ar no. ir no. eielson afb alaskaalaskacollection.library.uaf.edu/eafbsc/cd1/ar666-1.pdf ·...

AR No.

IR No.

EIELSON AFB ALASKA

Administrative Record Cover Sheet

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THE UNITED STATES AIR FORCE INSTALLATION RESTORATION PROGRAM

FINAL SITE SPECIFIC QUALITY ASSURANCE PROJECT PLAN

CONCEPTUAL SITE MODEL UPDATE SOURCE AREA ST48

EIELSON AIR FORCE BASE, ALASKA

Prepared for: Air Force Center for Engineering and the Environment

Contract No. FA8903-08-D-8791-0026

February 2012

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FINAL SITE SPECIFIC QUALITY ASSURANCE PROJECT PLAN

CONCEPTUAL SITE MODEL UPDATE SOURCE AREA ST48

EIELSON AIR FORCE BASE, ALASKA

Prepared for:

Air Force Center for Engineering and the Environment Contract No. FA8903-08-D-8791-0026

Prepared by:

EA Engineering, Science, and Technology, Inc. 3544 International Street Fairbanks, Alaska 99701

February 2012

Table of Contents Title: Site Specific QAPP for Source Area ST48 Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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TABLE OF CONTENTS SECTION PAGE List of Figures………...……………………………………………………………… ....... …..TOC-3 List of Tables………...……………………………………………………………… ........ …..TOC-4 List of Appendices.…………………………………………………………………. ............. .TOC-5 List of Acronyms And Abbreviations…………………………………………………. ........... .AA-1 1.0 INTRODUCTION ....................................................................................................... 1

1.1 Purpose ..................................................................................................................... 1 1.2 Background ............................................................................................................... 2 1.3 Objectives and Approach........................................................................................... 3 QAPP Worksheet #1 Title and Approval Page ............................................................... 1-1 QAPP Worksheet #2 QAPP Identifying Information ....................................................... 2-1 QAPP Worksheet #3 Distribution List ............................................................................ 3-1 QAPP Worksheet #4 Project Personnel Sign-Off Sheet ................................................. 4-1 QAPP Worksheet #5 Project Organizational Chart ........................................................ 5-1 QAPP Worksheet #6 Communication Pathways ............................................................ 6-1 QAPP Worksheet #7 Personnel Responsibilities and Qualifications Table .................... 7-1 QAPP Worksheet #8 Special Personnel Training Requirements Table .......................... 8-1 QAPP Worksheet #9 Project Scoping Session Participants Sheet ................................. 9-1 QAPP Worksheet #10 Problem Definition .................................................................... 10-1 QAPP Worksheet #11 Project Quality Objectives/Systematic Planning Process Statements ................................................................................................................. 11-1 QAPP Worksheet #12 Measurement Performance Criteria Table ................................ 12-1 QAPP Worksheet #13 Secondary Data Criteria and Limitations Table ........................ 13-1 QAPP Worksheet #14 Summary of Project Tasks ....................................................... 14-1 QAPP Worksheet #15 Reference List and Evaluation Tables ...................................... 15-1 QAPP Worksheet #16 Project Schedule/Timeline Table .............................................. 16-1 QAPP Worksheet #17 Sample Design and Rationale .................................................. 17-1 QAPP Worksheet #18 Sampling Locations and Methods/SOP Requirements Table .. 18-1 QAPP Worksheet #19 Analytical SOP Requirements Table ........................................ 19-1 QAPP Worksheet #20 Field Quality Control Sample Summary Table .......................... 20-1 QAPP Worksheet #21 Project Sampling SOP References Table ................................. 21-1 QAPP Worksheet #22 Field Equipment Calibration, Maintenance, Testing, and Inspection Table ........................................................................................................................... 22-1 QAPP Worksheet #23 Analytical SOP References Table ............................................ 23-1 QAPP Worksheet #24 Analytical Instrument Calibration Table .................................... 24-1 QAPP Worksheet #25 Analytical Instrument and Equipment Maintenance, Testing, and Inspection Table .......................................................................................................... 25-1 QAPP Worksheet #26 Sample Handling System ......................................................... 26-1 QAPP Worksheet #27 Sample Custody Requirements ................................................ 27-1 QAPP Worksheet #28 QC Samples Table ................................................................... 28-1 QAPP Worksheet #29 Project Documents and Records Table .................................... 29-1 QAPP Worksheet #30 Analytical Services Table ......................................................... 30-1 QAPP Worksheet #31 Planned Project Assessment Table .......................................... 31-1 QAPP Worksheet #32 Assessment Findings And Corrective Response Actions ......... 32-1 QAPP Worksheet #33 QA Management Reports Table ............................................... 33-1 QAPP Worksheet #34 Verification (Step I) Process Table ........................................... 34-1


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QAPP Worksheet #35 Validation (Steps IIa And IIb) Process Table ............................ 35-1 QAPP Worksheet #36 Validation (Steps IIa and IIb) Summary Table .......................... 36-1 QAPP Worksheet #37 Usability Assessment ............................................................... 37-1

2.0 REFERENCES ...................................................................................................... R-1


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FIGURES

Figure 10-1 Location of Source Area ST48 Figure 10-2 Site Features Figure 10-3 Historical Groundwater Monitoring Locations and Select Concentrations Figure 10-4 1988/1989 and 1993 Soil Sampling Summary Figure 10-5 2002 Post Bioventing Soil Sampling Locations and Detected Concentrations Figure 10-6 2002 Post Bioventing Soil Gas Sampling Locations and Detected Concentrations Figure 10-7 Bioventing System Site Layout Figure 10-8 Conceptual Site Model Figure 11-1 Benzene and NAPL Plumes with Potential Direct Push Sample Area


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TABLES Table 1-1 UFP Worksheets Table 10-1 Contaminants of Concern Summary (OU1 RI) Table 10-2 Concentrations of Chemicals of Potential Concern (OU1 BRA) Table 10-3 Chemical Specific Final Remediation Goals Table 10-4 Maximum Groundwater Monitoring Results Summary from Sitewide Monitoring Table 10-5 Concentrations (µg/L) of Organic Compounds in Groundwater Samples Table 10-6 Analytical Suites and Potentially Affected Matrices Table 11-1 Proposed Field Sampling Program Table 11-2 Existing Well Construction Information Table 15-1 Reference Limits and Project Quantitation Limits for Soil Table 15-2 Reference Limits and Project Quantitation Limits for Groundwater Table 15-3a Reference Limits and Project Quantitation Limits for Air (Indoor Air) Table 15-3b Reference Limits and Project Quantitation Limits for Air (Sub-slab and Soil Gas) Table 15-4 Evaluation Approach for Compounds for Which PALs Exceed Various Laboratory

Limits


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APPENDICES1 Appendix A EA Field Sampling Standard Operating Procedures Appendix B Field and Data Reporting Forms Appendix C TestAmerica Laboratories, Inc., Quality Assurance Manual and Environmental

Laboratory Accreditation Program Certification Appendix D TestAmerica Laboratories, Inc., Standard Operating Procedures Appendix E Air Toxics Ltd., Laboratory Quality Assurance Program Environmental Laboratory

Accreditation Program Certification Appendix F Air Toxics Ltd., Compendium Method TO-15 Appendix G Triad Environmental Solutions, Inc., Quality Assurance Plan for Field Use of the

Direct Sampling Ion Trap Mass Spectrometer using U.S. Environmental Protection Agency SW 846 Method 8265

Appendix H Triad Environmental Solutions, Inc., Standard Operating Procedure for Sampling

and Analysis of Volatile Organic Compounds in Water Using Direct Sampling Ion Trap Mass Spectrometry

Appendix I Method 8265 – Volatile Organic Compounds in Water, Soil, Soil Gas, and Air

by Direct Sampling Ion Trap Mass Spectrometry Appendix J 2011 Health and Safety Plan for Eielson Air Force Base Appendix K Statistically-Generated Laboratory Control Limits for Precision and Accuracy Appendix L Draft Vapor Intrusion Guidance for Contaminated Sites (2009) Appendix M Response to Comments (THIS APPENDIX CONTAINS INFORMATION

RELATED TO NATIONAL SECURITY AND SHOULD NOT BE RELEASED TO THE PUBLIC)

1 With the exception of Appendices L and M, all appendices are located in the Installation-Wide Generic Quality Assurance Project Plan, Eielson AFB (USAF 2012).


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Acronyms and Abbreviations Title: Site Specific QAPP for Source Area ST48 Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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ACRONYMS AND ABBREVIATIONS °C Degree(s) Celsius µg/L Microgram(s) per liter µg/kg Microgram(s) per kilogram AAC Alaska Administrative Code ADEC Alaska Department of Environmental Conservation AFB Air Force Base AFCEE Air Force Center for Engineering and the Environment ARAR Applicable or relevant and appropriate requirement ASTM American Society for Testing and Materials bgs Below ground surface BRA Baseline Risk Assessment BTEX Benzene, toluene, ethylbenzene, and xylene CERCLA Comprehensive Environmental Response, Compensation, and Liability Act CFR Code of Federal Regulations COC Contaminants of concern CSM Conceptual site model DBCP 1,2-dibromo-3-chloropropane DCA 1,2 dichloroethene DCE Dichloroethane DDD Dichlorodiphenyldichloroethane DDE Dichlorodiphenyldichloro-ethylene DDT Dichlorodiphenyltrichloroethane DL Detection limit DoD Department of Defense DQO Data quality objectives DRO Diesel range organic DSITMS Direct sampling ion mass trap spectrometry EA EA Engineering, Science, and Technology, Inc. EDB 1,2-dibromoethane (ethylene dibromide) ELAP Environmental Laboratory Accreditation Program ERPIMS Environmental Restoration Program Information Management System ESD Explanation of Significant Difference ft Foot (feet) FS Feasibility Study


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GPS Global Positioning System GRO Gasoline range organic IC Institutional Control ICP Inductively coupled plasma IDW Investigation-derived waste in. Inch(es) kd Distribution coefficient LOD Limit of detection LTM Long-term monitoring LTO Long-term operations MAROS Monitoring and Remediation Optimization System MCL Maximum contaminant level mg/kg Milligrams per kilogram mg/kg-day Milligrams per kilogram per day mL Milliliter(s) msl Mean sea level NA Not applicable NAPL Non-aqueous phase liquid O&M Operations and maintenance OU Operable unit PAH Polycyclic aromatic hydrocarbon PAL Project action level PCB Polychlorinated biphenyl PCE Tetrachloroethene pH Potential hydrogen PID Photoionization detector ppm Parts per million PQL Practical quantitation limit PQO Project quality objective PVC Polyvinyl chloride QA Quality assurance QAPP Quality assurance project plan QC Quality control QSM Quality Systems Manual


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RA Remedial Action RAO Remedial action objective RI Remedial Investigation RL Reporting limit ROD Record of Decision RPO Remedial Process Optimization RSD Relative standard deviation RSL Regional Screening Level SARA Superfund Amendments and Reauthorization Act of 1986 SOP Standard Operating Procedure SW USEPA Solid Waste Method SWMP Sitewide Monitoring Program SVE Soil Vapor Extraction SVOCs Semivolatile organic compound TCE Trichloroethene T&D Treatment and Disposal TDS Total dissolved solids TestAmerica TestAmerica, Inc. TOC Total organic carbon TPH Total petroleum hydrocarbons Triad Triad Environmental Solutions, Inc. UFP Uniform Federal Policy USAF U.S. Air Force USEPA U.S. Environmental Protection Agency VES Vapor extraction system VOC Volatile organic compound


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Introduction Title: Site Specific QAPP for Source Area ST48 Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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1.0 INTRODUCTION The Air Force Center for Engineering and the Environment (AFCEE) has contracted EA Engineering, Science, and Technology Inc. (EA) to perform a conceptual site model (CSM) update at Source Area ST48 at Eielson Air Force Base (AFB), Alaska. 1.1 Purpose The work is being performed under the Installation Restoration Program, which was developed to provide response actions for Department of Defense (DoD) installations as required by Section 120 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) (as clarified by Executive Order 12316 and amended by the Superfund Amendments and Reauthorization Act of 1986 [SARA]). The current DoD policy was specified in Defense Environmental Quality Program Policy Memorandum 81-5, dated 11 December 1981, and was implemented by the U.S. Air Force (USAF) in a message dated 21 January 1982. The DoD policy is to identify and fully evaluate suspected problems associated with past operations which may have caused hazardous waste contamination, and to implement remedial actions that will minimize the hazards to human health and the environment resulting from such past operations. This investigation is being performed to close data gaps in the current conceptual site model and to fully delineate source area(s) and plume boundaries. Results will be used to determine the protectiveness of the selected remedy, to select future remedial actions that are in compliance with the USAF’s new accelerated site completion policy, and ultimately to reach site closure under both State and Federal Regulations. An Explanation of Significant Difference (ESD) is not anticipated, but may be required if a change in remedy is necessary to achieve closure. This investigation will be performed using the Triad process where all stakeholders have input in decision making process to guide the investigation toward a common goal – complete delineation and optimally the protection of human health and the environment. As such, the data and analysis progress from existing data review to collection of screening level and definitive soil and groundwater data, followed by monitoring well construction and definitive data collection. The Triad process will culminate in permanent monitoring well construction and establishment of a permanent monitoring well network from which to evaluate plume stability and establish concentration trends. The report produced as a result of this investigation will discuss long-term monitoring (LTM) in the recommendations. This Quality Assurance Project Plan (QAPP) outlines the policies, organization, and specific quality assurance (QA)/quality control (QC) measures associated with the collection, analysis, and reporting of data collected in support of the remedial actions to achieve the data quality


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goals. This document meets the requirements and elements set forth in the Intergovernmental Data Quality Task Force Uniform Federal Policy (UFP) for QAPPs (U.S. Environmental Protection Agency [USEPA] 2005). An Installation-Wide Generic QAPP has been prepared to address multiple existing source areas at Eielson AFB for common elements or work sheets. This Site Specific QAPP has been prepared for Source Area ST48 and with the Installation-Wide Generic QAPP forms the complete UFP QAPP for ST48. Table 1-1 lists the 37 UFP QAPP worksheets and whether they have been designated generic or site specific. Site specific worksheets were developed for Source Area ST48 and compiled into this Site Specific QAPP. Generic worksheets within this QAPP refer back to the Installation-Wide Generic QAPP. This Site Specific QAPP and the Installation-Wide Generic QAPP will be used in combination as the UFP QAPP for Source Area ST48. The 37 UFP QAPP worksheets immediately follow this introduction. References used in the preparation of this QAPP are provided following the QAPP worksheets. Appendices consist of the following and are located in the Installation-Wide Generic QAPP:

• Appendix A: EA Field Sampling Standard Operating Procedures (SOPs)

• Appendix B: Field and Data Reporting Forms

• Appendix C: TestAmerica, Inc. (TestAmerica) QA Manual and Environmental Laboratory Accreditation Program (ELAP) Certification

• Appendix D: TestAmerica SOPs

• Appendix E: Air Toxics Ltd. Laboratory QA Program ELAP Certification

• Appendix F: Air Toxics Ltd. Compendium Method TO-15

• Appendix G: Triad Environmental Solutions, Inc. QA Plan for Field Use of the Direct

Sampling Ion Trap Mass Spectrometer using USEPA Solid Waste (SW) 846 Method 8265

• Appendix H: Triad SOP for Sampling and Analysis of Volatile Organic Compounds

(VOCs) in Water Using Direct Sampling Ion Trap Mass Spectrometry

• Appendix I: Method 8265 – VOCs in Water, Soil, Soil Gas, and Air by Direct Sampling Ion Trap Mass Spectrometry

• Appendix J: Health and Safety Plan


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• Appendix K: Statistically-Generated Laboratory Control Limits for Precision and Accuracy

• Appendix L: Draft Vapor Intrusion Guidance for Contaminated Sites (2009)

• Appendix M: Response to Comments

1.2 Background Eielson AFB is located 24 miles southeast of Fairbanks and includes an area of approximately 19,700 acres (Figure 10-1). Since its establishment in 1944, the mission of Eielson AFB has been to train and equip personnel for close air support of ground troops in an arctic environment. Operations at Eielson AFB have generated varying quantities of hazardous and non-hazardous wastes from industrial and airfield operations, fire training, and fuel management. On 21 November 1989, the USEPA listed Eielson AFB on the National Priorities List. This listing designated the facility as a federal Superfund site subject to the remedial response requirements of CERCLA, as amended by SARA. In May 1991, the USAF, State of Alaska, and USEPA entered into the Federal Facility Agreement under CERCLA Section 120, which established the procedural framework and schedule for developing, implementing, and monitoring CERCLA response actions. An additional goal of the Federal Facility Agreement was to integrate the USAF’s CERCLA response obligations and Resource Conservation and Recovery Act corrective action obligations. Under the Federal Facility Agreement, potential known source areas were either grouped into six Operable Units (OUs) based on similar contaminant and environmental characteristics, or were included for evaluation under a source evaluation report. The site-wide study followed the investigations under separate OUs to evaluate any cumulative risks at the Base. Source Area ST48 is in OU1 and is located in the east-central portion of Eielson AFB, near the intersection of Division Street and Industrial Drive. An unknown quantity of fuel has been released at this site with the source believed to be leakage from a buried multi-fuel pipeline. Remedial actions have taken place on this site since 1992 and remedies, as prescribed in the 1992 interim Record of Decision (ROD) and 1994 ROD, have included: free product removal through passive skimming; bioventing and soil vapor extraction to remediate soil contamination; and groundwater monitoring. In 1992, a vacuum extraction system was installed to remove non-aqueous phase liquid (NAPL), but the system was soon converted into bioventing wells. In 1996, it was updated to include air injection and extraction points. Bioventing operations at ST48 ended in 2002 and were decommissioned in 2003, because the goals set for remediation were met within the area of influence of the bioventing system. However, contamination remained in other areas of the site.


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1.3 OBJECTIVES AND APPROACH The objectives of the CSM update are to address data gaps in the nature and extent of contamination as follows:

1. Delineate the nature and extent of remaining soil impacts; 2. Delineate the horizontal and vertical extent of the groundwater solute plume; 3. Establish basic hydrogeologic characteristics.

The information collected will be used to address existing data gaps and prepare an updated CSM to provide a clear path forward regarding the protectiveness of future remediation and/or monitoring efforts. The overall strategy for conducting the field work is based on the application of the systematic planning process, which consists of a sequence of logical steps to address the sampling rationale, decision criteria, and approaches in selecting a sampling design. In addition, the Triad decision-making process for hazardous waste sites will be implemented. Triad offers a technically defensible methodology for managing decision uncertainty that leverages innovative characterization tools and strategies, and is based on three primary components: (1) systematic planning; (2) dynamic work strategies; and (3) real-time measurement systems.


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TABLE 1-1 UFP WORKSHEETS Worksheet No. Worksheet Title Generic vs. Site Specific

1 Title and Approval Page Site specific 2 QAPP Identifying Information Site specific 3 Distribution List Generic 4 Project Personnel Sign-Off Sheet Generic 5 Project Organizational Chart Generic 6 Communication Pathways Generic 7 Personnel Responsibilities and Qualifications Table Generic 8 Special Personnel Training Requirements Table Generic 9 Project Scoping Session Participants Sheet Site specific 10 Problem Definition Site specific

11 Project Quality Objectives/Systematic Planning Process Statements Site specific

12 Measurement Performance Criteria Table Generic 13 Secondary Data Criteria and Limitations Table Site specific 14 Summary of Project Tasks Site specific 15 Reference Limits and Evaluation Table Site specific 16 Project Schedule/Timeline Table Site specific 17 Sampling Design and Rationale Site specific

18 Sampling Locations and Methods/SOP Requirements Table Generic

19 Analytical SOP Requirements Table Generic 20 Field Quality Control Sample Summary Table Generic 21 Project Sampling SOP Reference Table Generic

22 Field Equipment Calibration, Maintenance, Testing, and Inspection Table Generic

23 Analytical SOP Reference Table Generic 24 Analytical Instrument Calibration Table Generic

25 Analytical Instrument and Equipment Maintenance, Testing, and Inspection Table Generic

26 Sample Handling System Generic 27 Sample Custody Requirements Generic 28 QC Samples Table Generic 29 Project Documents and Records Table Generic 30 Analytical Services Table Generic 31 Planned Project Assessment Table Generic 32 Assessment Findings and Response Actions Generic 33 QA Management Reports Table Generic 34 Sampling and Analysis Verification (Step I) Process Table Generic

35 Sampling and Analysis Validation (Steps IIa and IIb) Process Table Generic

36 Sampling and Analysis Validation (Steps IIa and IIb) Summary Table Generic

37 Data Usability Assessment Generic Note: Generic worksheets are provided in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).


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QAPP Worksheet #1 Title: Site Specific QAPP for Source Area ST48 Title and Approval Page Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #1 TITLE AND APPROVAL PAGE

Site Name/Project Name: Source Area ST48/Conceptual Site Model Update

Site Location: Eielson AFB, Fairbanks North Star Borough, Alaska

Document Title: Site Specific QAPP, Conceptual Site Model Update, Source Area ST48

Lead Organization: AFCEE

Preparer’s Name and Organizational Affiliation:

Mark Wilkinson (Project Manager/EA), Brenda Nuding (Project Chemist/EA), and John Harding (EA)

Preparer’s Address, Telephone, Number and E-mail address:

EA Engineering, Science, and Technology, Inc. 3544 International Street Fairbanks, Alaska 99701 (907) 456-4751

Preparation Date (Month/Year): February 2012

Investigative Organization’s Project Manager/Date: Printed Name/Organization: Mark Wilkinson/EA

Investigative Organization’s Project QA/QC Manager/Date: Printed Name/Organization: Frank Barranco/EA

Lead Organization’s Project Manager/Date: Printed Name/Organization: Tracy Kissler/AFCEE Contracting Officer’s

Representative Other Approval Signatures/Date:

Printed Name/Title: David Beistel/Eielson AFB

Other Approval Signatures/Date:

Printed Name/Title: Kimberly DeRuyter/Alaska Department of Environmental Conservation (ADEC)

Other Approval Signatures/Date:

Printed Name/Title: Aaron Lambert/USEPA Region 10

Document Control Numbering System: Not required for this project

QAPP Worksheet #1 Title: Site Specific QAPP for Source Area ST48 Title and Approval Page Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #2 Title: Site Specific QAPP for Source Area ST48 QAPP Identifying Information Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #2 QAPP IDENTIFYING INFORMATION Site Name/Project Name: Source Area ST48/Conceptual Site Model

Update Site Location: Eielson AFB, Fairbanks North

Star Borough, Alaska Title: Site Specific QAPP, Conceptual Site

Model Update, Source Area ST48 Site Number/Code: Not applicable (NA) Revision Number: 0 Operable Unit: Part of OU1 Revision Date: February 2012 Contractor Name: EA Engineering, Science, and Technology, Inc. Contract Title: Eielson AFB Multi-Site Investigation, Feasibility Study and

Technical/Regulatory Support Contract at Eielson AFB Contractor Number: NA Work Assignment Number: NA 1. Identify regulatory program: CERCLA Executive Order 12316 and amended by SARA 2. Identify approval entity: AFCEE/Eielson AFB/ADEC/USEPA Region 10 3. The QAPP is (select one): Generic X Project Specific 4. List dates of scoping sessions that were held: 10 May 2011 5. List dates and titles of QAPP documents written for previous site work, if applicable:

Title Approval Date

None since the ROD was approved. NA

6. List organization partners (stakeholders and connection with lead organization):

Partners Connection AFCEE Sponsor organization

Eielson AFB Lead organization/Technical oversight organization

USEPA Region 10 Federal regulatory agency ADEC State regulatory agency

7. List data users: Same as above under No. 6.

QAPP Worksheet #2 Title: Site Specific QAPP for Source Area ST48 QAPP Identifying Information Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #3 Title: Site Specific QAPP for Source Area ST48 Distribution List Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #3 DISTRIBUTION LIST This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #3 Title: Site Specific QAPP for Source Area ST48 Distribution List Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #4 Title: Site Specific QAPP for Source Area ST48 Project Personnel Sign-Off Sheet Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #4 PROJECT PERSONNEL SIGN-OFF SHEET This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #4 Title: Site Specific QAPP for Source Area ST48 Project Personnel Sign-Off Sheet Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #5 Title: Site Specific QAPP for Source Area ST48 Project Organizational Chart Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #5 PROJECT ORGANIZATIONAL CHART This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #5 Title: Site Specific QAPP for Source Area ST48 Project Organizational Chart Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #6 Title: Site Specific QAPP for Source Area ST48 Communication Pathways Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #6 COMMUNICATION PATHWAYS This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #6 Title: Site Specific QAPP for Source Area ST48 Communication Pathways Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #7 Title: Site Specific QAPP for Source Area ST48 Personnel Responsibilities and Qualifications Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #7 PERSONNEL RESPONSIBILITIES AND QUALIFICATIONS TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #7 Title: Site Specific QAPP for Source Area ST48 Personnel Responsibilities and Qualifications Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #8 Title: Site Specific QAPP for Source Area ST48 Special Personnel Training Requirements Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #8 SPECIAL PERSONNEL TRAINING REQUIREMENTS TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #8 Title: Site Specific QAPP for Source Area ST48 Special Personnel Training Requirements Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #9 Title: Site Specific QAPP for Source Area ST48 Project Scoping Session Participants Sheet Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #9 PROJECT SCOPING SESSION PARTICIPANTS SHEET Site Name/Project Name: Source Area ST48 Conceptual Site Model Update Site Location: Eielson AFB, Fairbanks North Star Borough, Alaska Projected Date(s) of Sampling: Spring/Summer 2012

Project Manager: Mark Wilkinson, EA Date of Session: 10 May 2011 Scoping Session Purpose: Discussed existing data, plume delineation and soil data gaps, and data needs.

Name Organization Project Role Phone E-mail Address Aaron Lambert USEPA USEPA Remedial Project Manager (206) 553-5122 [email protected] Amy Dahl Tech Law USEPA Contract Chemist (206) 577-3050 [email protected] Kim DeRuyter ADEC ADEC Project Manager (907) 451-2752 [email protected] Katie Beutel ADEC ADEC Project Manager (907) 451-2158 [email protected] Dave Beistel Eielson AFB Eielson Remedial Project Manager (907) 377-4299 [email protected] Mark Wilkinson EA EA Project Manager (907) 456-4751 [email protected] Jay Snyder EA EA Hydrogeologist (505) 224-9013 [email protected] Kwasi Boateng USEPA USEPA Hydrogeologist (206) 553-0526 [email protected] Comments The project scoping meeting for the updated CSM at Source Area ST48 took place on 10 May 2011, in Fairbanks, Alaska. Mr. Kwasi Boateng (USEPA Region 10), Mr. Aaron Lambert (USEPA Region 10), Ms. Amy Dahl (Tech Law), and Mr. Jay Snyder (EA) participated by conference call. The purpose of the scoping meeting was to provide the stakeholders an opportunity to discuss the CSM approach and gain consensus on the path forward. A description of the 10 May 2011 scoping meeting summary and materials presented for discussion by EA are included in the Eielson AFB Workgroup Meeting Minutes Notes, documenting the Eielson AFB Team meeting. This document has received the

QAPP Worksheet #9 Title: Site Specific QAPP for Source Area ST48 Project Scoping Session Participants Sheet Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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approval of the USAF, USEPA, and Alaska Department of Environmental Conservation (ADEC). The following list includes the items discussed during the meeting:

• The CSM was discussed as centering on humans as the receptor. • Plenty of existing data for both soil and vertical groundwater with no issue with either. • Investigate smear zone and shallow groundwater plumes.

QAPP Worksheet #10 Title: Site Specific QAPP for Source Area ST48 Problem Definition Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #10 PROBLEM DEFINITION This worksheet describes the environmental concerns at Source Area ST48. The site location and its vicinity are shown on Figure 10-1. The CSM was developed using existing information and working assumptions about the physical site conditions; the nature, occurrence, and distribution of contaminants; fate and transport processes; and the potential human and ecological receptors at the site. The CSM presented in this QAPP is based on the current understanding of site conditions, and will be refined or updated based on results of field sampling operations performed according to this QAPP. Project Background As discussed in the Introduction Worksheet, potential source areas at Eielson AFB requiring a Remedial Investigation (RI)/ Feasibility Study (FS) were grouped into six OUs based on similar contaminant or environmental characteristics. ST48 is in OU1 which consists of eight source areas where fuel contamination has been released to the soil and groundwater from fuel storage and/or fuel delivery systems. According to the OU1 Baseline Risk Assessment, potential source areas within OU1 were grouped together because they have NAPL (floating product) contamination. ST48 is located in the east-central portion of Eielson AFB, near the intersection of Division Street and Industrial Drive. The source area is approximately 1.5-acres in size with flat topography. The contaminants at this source area were initially discovered as part of an investigation for Source Area ST18. In 1987, more than 30 soil gas samples were installed and measured at ST18. The highest petroleum hydrocarbon concentration discovered during this initial survey was located south of Division Street and east of the railroad tracks (Figure 10-2). This location is near where the pipeline took a 90 degree turn from the west towards the north and evidently crossed Division Street (U.S. Army Corps of Engineers [USACE] 1995). It was determined that an unknown quantity of fuel was released south and west of the Base power and heat plant. According to the RI/FS for the Source Area ST48 Power Plant Fuel Leak (USAF 1992a), the suspected hydrocarbon source is an abandoned fuel system, consisting of two buried pipelines (3-inch diameter gasoline and 3-inch-diameter diesel-fuel pipes) that run along Industrial Drive and Division Street immediately south of the Power Plant. The fuel system connected the Eielson AFB bulk fuel storage tanks to an old military service station. The suspected source of petroleum contamination is leakage from the lines where they passed beneath Industrial Drive just south of Division Street. It is not known if the pipelines were drained and purged when they were taken out of service (USAF 1992a).


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In 1987, benzene, toluene, and trichloroethene (TCE) were detected in Well D (USAF 1992a). For security reasons, Well D is not identified on any maps. NAPL was observed at ST48, primarily in the area south of the intersection of Industrial Drive and Division Street. Product thickness in this area peaked between 1989 and 1991. However, floating product north of Industrial Drive appeared to be increasing in the early 1990s, possibly due to dewatering activities during construction in that area. Several chlorinated VOCs have been detected in groundwater at this source area over the years. The suspected chlorinated hydrocarbon source is a former dry well at Building 3423 in ST18, located approximately 500 feet (ft) south of ST48 (see Figure 10-2), which may have been used for solvent disposal (USAF 1994b). Remedial actions (RA) have taken place on this site since 1992. The remedies, as prescribed in the 1992 Interim ROD (USAF 1992b) and 1994 ROD (USAF 1994a), have included: vacuum extraction; free product removal through passive skimming; and bioventing and soil vapor extraction (SVE) to remediate soil contamination. In 1992, a vacuum extraction system (VES) was installed to remove NAPL, but the system was soon converted to bioventing. It was modified in 1996 to include air injection and extraction points (USAF 1997b). In addition, exposure to contaminated groundwater and soil at ST48 is prevented through the implementation of institutional controls (ICs). The ICs prevent human exposure to contaminants at concentrations above federal and state standards by restricting activities at the site (USAF 1998a). Additional background information regarding ST48 is presented in the synopsis of secondary data as well as in the historical site reports. The Problem to be Addressed by the Project A significant portion of ST48 was cleaned up via the interim remedial actions mentioned above. Recent review of confirmation samples collected at the termination of bioventing indicated a data gap in soil delineation at the upgradient edge of the former NAPL plume, as well as in the horizontal and vertical delineation of groundwater contamination. The existing CSM will be refined or updated based on the data collected under this QAPP to reflect current conditions, particularly with respect to remaining contaminant concentrations, and will be used to design a clear path forward regarding actions necessary to close the site. A network of permanent monitoring wells will be established and a regimen for groundwater monitoring will be developed to establish contaminant concentrations and trends, and to evaluate plume stability. LTM of this network will be addressed under a separate Installation-Wide Monitoring Program. The Environmental Questions Being Asked

• What are the contaminants of concern at ST48?


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Groundwater: • What is the horizontal extent of the groundwater plume?

• What is the vertical extent of the groundwater plume?

• What are the groundwater contaminant concentrations for all COCs? Future

groundwater monitoring (under the Installation-Wide Monitoring Program) will evaluate if the plume is stable or shrinking.

• Is NAPL still present at the site impacting any wells located in the vicinity?

Soil:

• What is the current horizontal extent of the soil source?

• What is the current vertical extent of the soil source?

• What are the current soil contaminant concentrations in the remediation area and in the impacted area at the upgradient edge of the former NAPL plume?

Air:

• Have contaminants volatilized from contaminated soil and/or groundwater to impact indoor air?

A Synopsis of Secondary Data or Information from Historical Site Reports Historical spills and operations have resulted in groundwater and soil contamination from petroleum-based products and chlorinated solvents at the site. The following sections summarize reports that describe results of investigations and studies completed at ST48. This historical information is further summarized and evaluated in this Worksheet under the sections “The Possible Classes of Contaminants and The Affected Matrices (Source Material)” and “The Rationale for Inclusion of Chemical and Nonchemical Analysis”. The following documents are discussed below:

• Draft Installation Restoration Program RI/FS, Stage 3, April 1989 (USAF 1989a)

• Installation Restoration Program RI/FS, Work Plan, May 1989 (USAF 1989b)

• Source Area ST48 Power Plant Fuel Leak, Installation Restoration Program RI/FS, Final Report, February 1992 (USAF 1992a)


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• Operable Unit 1B Interim ROD, September 1992 (USAF 1992b)

• Final Remedial Design Operable Unit 1B Source Area, ST48, October 1993 (USAF 1993b)

• Remedial Investigation Report: Operable Unit 1, February 1994 (USAF 1994b)

• Operable Unit 1 Final Baseline Risk Assessment, May 1994 (USAF 1994c)

• Operable Unit 1 ROD, September 1994 (USAF 1994a)

• Final Report on Microwell Investigations of Operable Units 1 & 2 at Eielson Air Force

Base, Alaska, April 1995 (USACE 1995)

• Final Remedial Design, Operable Unit 1, November 1995 (USAF 1995b)

• Final 1996 Operable Unit 1 Pilot Study Monitoring Report, October1997 (USAF 1997b)

• Operable Unit 1 Remedial Action Summary Report, August 1998 (USAF 1998a)

• First Five-Year ROD Review, September 1998 (USAF 1998c)

• Remedial Process Optimization (RPO), Draft Final RPO Phase II Technical Report, December 2002 (USAF 2002)

• Second Five-Year ROD Review, September 2003 (USAF 2004) • Third Five-Year ROD Review, September 2008 (USAF 2008)

• Sitewide Monitoring Program Reports: 1993 (USAF 1993c), 1994 (USAF, 1995a), 1995

(USAF 1996), 1996 (USAF 1997a), 1997 (USAF 1998b), 2001 (USAF 2002a), 2002 (USAF 2003a), and 2006 (USAF 2007)

Installation Restoration Program and Remedial Investigations (up until 1992) Two 10-inch diameter dewatering wells were installed in 1967 north of the plant. Fuel was observed in these wells in June 1987 and strong hydrocarbon odors were encountered in the water from two construction dewatering wells installed at the south end of the plant. Benzene, TCE, and toluene were detected in Well D in January 1987. Following up on these findings, from July to October 1988, an RI was performed at the site that included a soil gas survey, soil borings, excavation of test pits, collection of soil and groundwater samples, natural gamma geophysical borehole logging, water level measurements, installation of monitoring wells,


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installation of free product probes, and slug testing. During this investigation, floating fuel product was found near abandoned gasoline and diesel fuel lines beneath Industrial Drive. The subsurface exploration encountered surface fill (where present) that was composed of sand and fly ash from the power plant (USAF 1989a). Seven borings installed were converted to monitoring wells and no free product was found in any of these wells. In addition, three test pits were excavated. A total of 14 soil samples were collected for laboratory analyses from the borings and test pit locations and one groundwater sample was collected from each of the monitoring wells and from two production wells. Samples were analyzed as follows (USAF 1989a):

• Soil samples: VOCs, semivolatile organic compounds (SVOCs), organochlorine pesticide, polychlorinated byphenyls (PCBs), petroleum hydrocarbons, arsenic, and lead.

• Groundwater samples: purgeable halocarbons and aromatics, SVOCs, petroleum

hydrocarbons; total and dissolved arsenic, mercury, and inductively coupled plasma (ICP) scan; total dissolved solids (TDS); common anions; and nitrogen.

The analytical investigation detected total petroleum hydrocarbons (TPH), benzene, chlorobenzene, ethylbenzene, toluene, xylenes, 2-methylnaphthalene, naphthalene, phenanthrene, and polychlorinated biphenyl (PCB) 1254 in soil. TPHs; benzene, ethylbenzene, toluene, xylenes (BTEX); 2,4-methylphenol; 2-methylnaphthalene; and naphthalene were detected in groundwater (USAF 1992a). The soil gas investigation revealed BTEX concentrations in vapor samples ranging from 0.01 parts per million (ppm) to nearly 45 ppm (USAF 1989a). In November 1988, based largely on the results of the summer field work, the base installed a 10-inch diameter static recovery well near the southwest corner of the Power Plant. As of November 1989, approximately 5 gallons of fuel had been recovered from the well (USAF 1992a). Based on the 1988 investigation, a number of objectives were identified in the 1989 Work Plan (USAF 1989b) for further investigation at ST48. These objectives included assessing the lateral and/or vertical distribution of free product, TPH, and benzene, evaluating groundwater quality, assessing the significance of metals concentrations in comparison to background conditions, and evaluating the potential impacts the contaminants may have on human and environmental health (USAF 1989b).

An additional field investigation was conducted from August through November 1989, which involved a geophysical survey for boring clearances, drilling borings, installing new monitoring wells, installing product probes, measuring groundwater elevations and floating product thickness, collecting soil samples and groundwater samples (USAF 1992a).


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The key findings of the 1988 and 1989 field investigations include the following:

• Floating product and benzene above the maximum contaminant level (MCL) of 5 micrograms per liter (µg/L) were detected in the groundwater (USAF 1992a). At that time, the floating fuel product was estimated to be approximately 100 by 100 ft with a maximum thickness of 1.51 ft (USAF 1992b). The estimated extent of free product is shown on Figure 10-3.

• TPH above the ADEC 100 milligrams per kilogram (mg/kg) action level were identified in

surface and subsurface soil collected from three areas. These areas are shown on Figure 10-3. The maximum detected concentration was 32,000 mg/kg. At that time, the volume of contaminated subsurface soil at ST48 was estimated to be 1,250 cubic yards, which underlies an estimated overburden of 1,850 cubic yards of uncontaminated soil. The volume of contaminated surface soil at ST48 was estimated at 550 cubic yards (USAF 1992a). The isolated detect at boring 48SB18 was detected in surface soil and was attributed at the time to a localized spill (USAF 1992a).

• A maximum benzene concentration of 7,100 µg/L was detected in groundwater probe

48FW11 near the abandoned fuel line under Division Street (USAF 1989a). Field screening indentified toluene, ethylbenzene, and trans-dichloroethene (trans-DCE) were above MCL in the groundwater, although these results were not confirmed by an analytical laboratory. 2,4-dimethylphenol was also detected in one sample from well 48M01 (USAF 1992a).

• TPH and SVOCs, including 2-methylnapthalene, naphthalene, and bis(2-

ethylhexyl)phthalate were detected in groundwater collected from wells located in the vicinity of the area where floating product was present in 1989 (USAF 1992a). In 1988, 2-methylnapthalene and naphthalene were also detected in this area, while bis(2-ethylhexyl)phthalate was detected in groundwater collected from a production well located to the north of the coal piles (see Figure 10-3 for locations of coal piles) (USAF 1989a).

• Fuel-related polycyclic aromatic hydrocarbons PAHs were detected in a soil test pit

excavated just east of the free product area (USAF 1992a).

• In 1989, the groundwater sample from well 53M03 was analyzed for metals. Data from this groundwater sample indicated that iron, manganese, and dissolved residue (TDS) concentrations exceeded their respective secondary MCLs and calculated maximum background levels. Total lead, barium, copper, magnesium, manganese, vanadium, and zinc were also all detected above the calculated maximum background values in 1989. Additional wells were also tested for lead, out of 10 wells sampled, two exceeded the action level (USAF 1989a).


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The final RI/FS for ST48 concluded that while data were needed to evaluate and implement full remedial measures at ST48, available information generally was adequate to select a remedial alternative (see the Interim ROD discussed below) and proceed with preliminary design while additional studies were being conducted (USAF 1992a). The results from the 1988 and 1989 sampling events were used to develop the analytical objectives for the next investigation, which was conducted in 1993. Interim ROD for OU1B (1992) In 1992, seven of the eight sites within OU1, including ST48, were identified for advanced remedial action due to presence of floating product on the groundwater and the potential for contaminants to reach drinking water supply wells. The interim action for the OU1B sites was intended to prevent further degradation of the groundwater quality by significantly reducing the volume of petroleum product floating on the groundwater. The Interim ROD for OU1B (USAF 1992b) presented the selected interim remedy as vacuum extraction of floating petroleum product combined with enhanced aerobic degradation of the fuel hydrocarbons in the vadose zone. The chemicals of primary concern were listed as BTEX. Remedial Investigation Report OU1 (1994) The RI report for OU1 presented conclusions on the nature and extent of surface and subsurface contamination at the eight OU1 sites based on field investigations conducted prior to 1994. COCs were developed by comparing sampling data with the risk-based concentrations from the USEPA’s National Contingency Plan (40 Code of Federal Regulations [CFR] 300) and Part A of the Risk Assessment Guidance for Superfund, Volume 1, Human Health Evaluation Manual) (USEPA 1989a). The results of the RI as they relate to ST48 are summarized below (USAF 1994b). Soil and groundwater samples were analyzed for halogenated volatile organics, aromatic volatile organics, SVOCs, arsenic, lead, mercury, and ICP metals. Soil samples were also analyzed for organochlorine pesticides, PCBs, and TPH (1994b). The following discussion summarizes the results of the RI, by contaminant and media. Free Product At the time of the RI, floating product was centered near the intersection of Industrial Drive and Division Street, and was present near the ash house. Product thickness south of the intersection of Industrial Drive and Division Street appeared to have peaked between 1989 and 1991, with floating product thickness decreasing between 1991 and 1993 (USAF 1994b). However, floating product north of Industrial Drive and Division Street near the ash storage


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facility appeared to be increasing in the early 1990s. Dewatering activities during the construction of the ash storage space, located north of the intersection of Industrial Drive and Division Street, might have caused the floating product to migrate north, because there are no other known potential sources (USAF 1992b and 1994b). Fuel-Related Contaminants Soil. In 1993, TPH was detected near the coal piles (11 mg/kg), however TPH was not detected above the 100 mg/kg guideline for soil as it was during the earlier investigation (USAF 1994b). Fuel-related PAHs, including naphthalene, and kerosene-range fuel hydrocarbons were detected in the soil in 1989 and 1993. Anthracene, benzo(a)anthracene, benzo(a)pyrene, and several other PAHs were detected in a surface soil sample collected near Division Street. A complete list of PAHs detected in the surface soil sample is presented on Figure 10-3. The highest concentration for benzo(a)pyrene exceeded the cleanup level reported in the RI. During the 1993 sampling, a surface soil sample was collected near the coal piles to assess the PAHs in coal; there were no detectable concentrations of semivolatile organic materials in this sample (USAF 1994b). The fuel-related PAHs are believed to be associated with the free product and are detected in soils within the smear zone of the water table (USAF 1994b). Groundwater. A groundwater sample collected near the middle of the NAPL area, contained benzene at a concentration of 910 µg/L. Data suggested that the benzene plume in 1993 extended from the free product area to Well D. During sampling in 1993, benzene concentrations in Well D ranged from less than 0.2 µg/L to 1.4 µg/L. In the early 1990s, Well D appeared to be creating a downward hydraulic gradient that was pulling the benzene down through the aquifer to the screened interval of Well D. PAHs, naphthalene and 2-methylnaphthalene, were detected in the areas where floating product was measured in the past (USAF 1994b). 2-methylnaphthalene was detected in three of seven groundwater samples collected in 1993. Naphthalene was detected in four of seven groundwater samples collected in 1993. Soil Gas. A 1993 soil gas survey in the area along the abandoned pipeline indicated the highest concentrations of soil gas near the 90 degree bends in the abandoned pipeline (1,700 to 2,000 ppm). One soil gas survey point located near the ash house indicated low concentrations of total volatile hydrocarbons (USAF 1994b).


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Solvents In 1993, trans-1, 2-dichloroethene (trans-1, 2-DCE) and TCE were detected. TCE was present in low concentrations across ST48 with the highest concentrations in an upgradient well suggesting a source area upgradient of ST48. Neither trans-1,2-DCE nor TCE were detected in groundwater at concentrations above the MCLs. This report concluded that trans-1,2-DCE and TCE were not site-related COCs because of higher concentrations in an upgradient well from a source believed to be an offsite dry well at ST18 (OU-2) (USAF 1994b). PCBs Soil. PCB 1254 was detected in a subsurface soil sample collected from a monitoring well borehole in 1988. However, PCBs were not detected in three soil samples (surface, 6.6 ft, and 11.8 ft) from a single boring collected in 1993. The 1993 soil boring was located adjacent to the borehole where PCBs were detected in 1988 (USAF 1994b). Groundwater. PCBs were not measured in groundwater during the 1993 sampling event. Pesticides Soil. Dichlorodiphenyltrichloroethane (DDT) was detected in surface soil at concentrations exceeding applicable or relevant and appropriate requirement (ARARs), however, no pesticides were found in the subsurface soil. The DDT decay products, dichlorodiphenyldichloroethane (DDD) and dichlorodiphenyldichloro-ethylene (DDE), were also detected. Groundwater. Pesticides were not measured in groundwater during the 1993 sampling event. Metals Soil. In 1993, two soil samples were analyzed for metals. No metals exceeded risk-based levels in soil (USAF 1994b). Groundwater. In 1993, seven groundwater samples were analyzed for metals. Antimony, arsenic, beryllium, cadmium, lead, and manganese exceeded risk-based levels in groundwater. The 1994 RI report concluded that the detected metal concentrations in groundwater samples were determined to be within background values or likely background/naturally occurring, with the exception of lead and possibly manganese. Lead was detected in an unfiltered groundwater sample at a concentration above background but below the MCL; however, lead was not detected in a filtered sample collected from the same well (USAF 1994b).


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COCs identified as part of the RI for groundwater, surface soil, and subsurface soil are presented in Table 10-1.

TABLE 10-1. CONTAMINANTS OF CONCERN SUMMARY (OU1 RI) SOURCE AREA ST48

EIELSON AFB, ALASKA

Contaminants of Concern Groundwater Surface

Soil Subsurface

Soil Antimony(a) X Arsenic(b) X

Beryllium(a) X Cadmium (b) X

Lead(c) X Manganese X

Benzene X Toluene X Xylenes X TPH X X PAHs (d) X X(e)

Notes: PAH = polycyclic aromatic hydrocarbon TPH = total petroleum hydrocarbons (a) No background established. (b) Statistical t-test indicates the values are not outside of background

statistical boundaries. (c) Does not exceed risk levels but is within 1 to 4 µg/L of the limit. (d) PAHs refers to PAHs from fuel sources. (e) PAHs includes PAHs from exhaust-related sources.

OU1 Baseline Risk Assessment (BRA) (1994) The BRA identified the following primary contaminants of concern associated with the fuel leak at ST48: TPH; nonchlorinated volatile organics, such as BTEX; PAHs; and trace amounts of metals (USAF 1994c). Metals of concern included barium, lead, manganese, mercury, and zinc in groundwater and beryllium and lead in surface soils. The chemicals of potential concern and maximum detected values are listed in Table 10-2. The BRA stated that contamination of the ambient air may occur when contaminants with high vapor pressures are released to the atmosphere from soil contamination. No high-vapor-pressure contaminants were detected in the soils of this source area; therefore, there was no anticipated risk associated with this exposure pathway. For the current industrial land use, the BRA identified that groundwater was not currently used so the exposure pathways associated with the groundwater medium were not evaluated further. (Note: impacts to nearby Well D were not considered in the BRA, although this was an active


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well.) For the future residential housing land use, the BRA assumed that future residences would utilize groundwater as a potable supply and to have garden plots. The BRA also assumed that future military and industrial land uses would use the area’s groundwater as a potable supply on a limited basis. These assumptions resulted in increased cancer risks for the future land use scenarios over the existing industrial land use analyzed in the BRA.

TABLE 10-2. CONCENTRATIONS OF CHEMICALS OF POTENTIAL CONCERN (OU1 BRA) SOURCE AREA ST48

EIELSON AFB, ALASKA

Analyte Matrix Code(s) Units Max. Value Detected Groundwater 1,2-Dichloroethane Water µg/L 0.489 2,4-Dimethylphenol Water µg/L 10 Barium (Unfiltered) Water µg/L 722 Benzene Water µg/L 7100 Ethylbenzene Water µg/L 950 Lead (Unfiltered) Water µg/L 152 Manganese Water µg/L 5670 Mercury (Filtered) Water µg/L 0.7 Methylene chloride Water µg/L 2.5 Naphthalene Water µg/L 440 TPH Water µg/L 4.00E+05 Tetrachloroethene Water µg/L 3.3 Toluene Water µg/L 6600 Trichloroethene Water µg/L 2.1 Zinc (Unfiltered) Water µg/L 72.4 m,p-xylenes Water µg/L 3300 trans-1,2-Dichloroethylene Water µg/L 490 Surface Soil 4,4'-DDT Soil µg/kg 180 Benz(a)anthracene Soil µg/kg 970 Benzo(a)pyrene Soil µg/kg 980 Benzo(b)fluoranthene Soil µg/kg 950 Benzo(k)fluoranthene Soil µg/kg 870 Beryllium Soil µg/kg 400 Chrysene Soil µg/kg 1100 Lead Soil µg/kg 23500 Subsurface Soil Arsenic Soil µg/kg 7400 Kerosene Soil µg/kg 3.70E+05 Notes: µg/L = micrograms per liter µg/kg = micrograms per kilogram TPH = total petroleum hydrocarbons


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OU1 ROD (1994) The ROD states, “[T]he contaminants of concern in groundwater are BTEX and the chlorinated solvents, tetrachloroethene and trans-1,2-dichloroethylene. Trans-1,2-dichloroethylene in the groundwater is not targeted for cleanup because it was detected in one sample from one location. Additional samples will be collected during the remedial design for OU1 to verify that this chemical is not present. Tetrachloroethene in the groundwater is not targeted for cleanup because its contribution to risk is low. Removal of this chemical will not significantly impact the risk level at this site. Benzene, ethylbenzene, and toluene contamination of subsurface soil may also present a future risk to groundwater” (USAF 1994a).

The ROD remedy required expanding the bioventing and SVE systems to remediate soil contamination that could leach into the groundwater, installing passive skimmers for free product recovery, monitoring, and the implementation of ICs (USAF 1994a). The goal of remediation at ST48 is to restore the beneficial functions of the groundwater and protect human and environmental health by removing the source of groundwater contamination. To accomplish this, the following remediation goals were established (see Table 10-3) for in-situ remediation (USAF 1994a).

TABLE 10-3. CHEMICAL SPECIFIC FINAL REMEDIATION GOALS (OU1 ROD) SOURCE AREA ST48

EIELSON AFB, ALASKA

Constituent Final Remediation Goal for Groundwater Established

by ARARs (µg/L)a

Final Remediation Goal for Soil and Shallow Sediments

(mg/kg)b Benzene 5 0.2 Toluene 1,000 80 Ethylbenzene 700 140 Xylenes 10,000 760 Notes: (a) Maximum Contaminant Level (MCL): 40 CFR Part 131, and 18 ACC Chapter 70.010 a and d, 70.015 through 70.0110, 18 AAC 80.070 (b) Based on leaching to groundwater (Appendix D of OU1 RI/FS, USAF 1994b). ARARs = Applicable or relevant and appropriate requirements µg/L = micrograms per liter mg/kg = milligrams per kilogram

MicroWell Investigation (1995) Eielson AFB worked with the USACE Cold Regions Research and Engineering Laboratory to conduct small diameter well investigations during the fall of 1994 (USACE 1995). ST48 was covered under this investigation.


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The objectives of the investigation were to:

• Minimize remedial design uncertainty by identifying possible design limitations; • Determine distribution of VOC contamination on the horizontal and vertical planes.; and • Conduct soil gas sampling.

Seven microwells were installed and sequential sampling was conducted. BTEX was present throughout the water column. Five of the seven wells had benzene concentrations above MCLs at all depths. One location had benzene (900 µg/L) and toluene (4,900 µg/L) concentrations above MCLs between 8 and 18 ft below ground surface (bgs). TPH-gasoline range organics (GRO) and TPH-diesel range organics (DRO) concentrations were above the current ADEC Groundwater Cleanup Levels. Nine soil gas probes were also installed to investigate the presence of BTEX in soil gas matrix. All soil gas sample concentrations were below the detection levels for the respective compounds. Sitewide Monitoring Program (1994-2006) The Sitewide Monitoring Program (SWMP) covers long-term environmental monitoring and restoration of sites at Eielson AFB under the Federal Facility Agreement and other environmental regulations. Environmental samples were collected and analyzed for select chemicals based on location-specific rationale described in the RI/FS. Samples were collected to evaluate contaminant concentrations from year to year. At ST48, groundwater samples were collected under the SWMP in 1994, 1995, 1996, 1997, 2002, and 2006 to identify trends in concentrations of COCs (USAF 2008). Table 10-4 reports the maximum concentrations of chemicals detected at ST48 for the SWMP. See Figure 10-3 for the location of each well where the maximum concentrations were detected (provided in parentheses after the contaminant concentrations). Note that while 1,2-dichloroethane (1,2-DCA) was only measured at concentrations above MCL during one SWMP monitoring event in 1996, 1,2-DCA was detected at concentrations exceeding the MCL in other sampling events in 1994 and 1995. Table 10-5 presents historical groundwater data for ST-48 originally presented in the 2006 Sitewide Monitoring Report (USAF 2007). Trans-1,2-DCE was analyzed in 1997 and 2002. All results for trans-1,2-DCE were two orders of magnitude less than the MCL. Naphthalene was analyzed in 2002. The maximum concentration detected for naphthalene was 754 µg/L, which exceeds the current ADEC cleanup level.


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TABLE 10-4. MAXIMUM GROUNDWATER MONITORING RESULTS SUMMARY FROM SITEWIDE MONITORING

SOURCE AREA ST48 EIELSON AFB, ALASKA

Year Benzene1 Toluene1 Ethyl-benzene1 Xylenes1 TPH-

GRO2 TPH-DRO2 TCE2 1,2-DCA2

MCLs 5 1,000 700 10,000 2,200 1,500 5 5

1994 ND ND ND ND NA NA 1.4 (18-3) ND

1995 240 (53M03)

25 (53M03)

47 (53M03)

490 (53M03)

2,300 (53M03)

7,000 (53M03)

<1 (53M03)

<1 (53M03)

1996 6,700 (48PP13)

3,700 (48PP13)

550 (48M08)

3,600 (48PP28) NA NA 1.1

(18-3) 61

(48PP13)

1997 3,800 (48M01)

62 (48M01)

220 (48M01)

1,420 (48M01) NA NA <1.0

(48M01) 4

(48M01)

2002 882 (48M08)

12,500 (48M08)

1,600 (48M08)

6,820 (48M08) NA NA 2.2

(48M08) <1.0

(48M08)

2006 23 (48M08B)

1,400 (48M08B)

900 (48M08B)

3,000 (48M08B) NA NA NA NA

All results and standards reported in µg/L

1 ROD Cleanup Level 2 ADEC Cleanup Level NA = not analyzed Bold = concentrations above MCL Source = SWMP USAF 1994, 1995, 1996, 1997, 2002, and 2006.

QAPP Worksheet #10Problem Definition

Title: Site Specific QAPP for Source Area ST48Revision Number: 0

Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Well No.Date

SampledSampling Depth(ft) Benzene Toluene Ethylbenzene Xylenes TPH GRO TPH DRO TCE 1,2-DCA

trans-1,2-DCE Naphthalene

Analytical Methods Notes

MCLs 5 1,000 700 10,000 1,300ADEC 1,500ADEC 5 5 100 1,460

18-6 1986 <5.0 <5.0 <5.0 <5.0 -- -- -- -- -- --18-6 1986 <5.0 <5.0 <5.0 <5.0 -- -- -- -- -- --18-6 09/15/91 <5.0 <5.0 <5.0 <5.0 -- -- <5.0 -- -- -- 5,6,8 a18-6 05/18/93 <2.0 -- -- -- -- -- <1.0 -- -- --18-6 07/26/94 <1.0 <1.0 <1.0 <1.0 <50 <100 <1.0 -- -- -- 1-4 b18-6 10/04/94 <1.0 <1.0 <1.0 <1.0 <50 600 <1.0 -- -- -- 1-4 b

18-6B 09/15/06 14.0 <0.1 <0.2 <0.2 <0.2 -- -- -- -- -- -- 7

48M01 1989 1,390 49 143 1,550 -- -- -- -- -- 1,5 a48M01 05/19/93 910 -- -- -- -- -- <1.0 -- -- 1,4,548M01 07/27/94 3,900 350 230 1,960 14,000 230,000 <1.0 36 -- 1-4 b,d,e48M01 10/04/94 3,600 82 170 1,240 13,000 -- <1.0 54 -- 1,2,4 d48M01 07/27/95 2,900 200 110 1,100 4,600 50,000 <25 32 -- 1-4 b48M01 09/08/95 3,300 89 480 5,100 25,000 97,000 <20 <20 -- 1-4 b,d,i48M01 07/29/96 4,600 87 290 1,980 -- -- <5.0 14 -- 1,4 b,j48M01 9/11/97, 3,800 62 220 1,420 -- -- <1.0 4 <1.0 1,4 b,k

48M03 10/06/89 0.3 <0.3 <0.5 <0.9 -- -- -- -- --48M03 10/06/89 <0.02 <0.3 <0.5 <0.4 -- -- -- -- -- 1,5 a48M03 05/18/93 <2.0 -- -- -- -- -- 0.31 -- -- 1,4,548M03 07/25/94 <1.0 <1.0 <1.0 <1.0 <50 270 <1.0 <1.0 -- 1-4 b48M03 10/04/94 <1.0 <1.0 <1.0 <1.0 <50 120 <1.0 <1.0 -- 1-4 b48M03 07/24/95 <1.0 <1.0 <1.0 1.1 <50 2,900 <1.0 <1.0 -- 1-4 b

48M04 09/29/89 <0.02 <0.3 <0.5 <0.4 -- -- -- -- -- 1,5 a48M04 05/17/93 0.1 -- -- -- -- -- <1.0 -- -- 1,4,548M04 07/21/94 <1.0 <1.0 <1.0 <1.0 <50 120 <1.0 <1.0 -- 1-4 b48M04 08/03/94 <1.0 <1.0 <1.0 <1.0 -- -- <0.5 <0.5 -- 1,4 b48M04 10/05/94 <1.0 <1.0 <1.0 <1.0 <50 130 <1.0 <1.0 -- 1-4 b48M04 09/08/95 <1.0 <1.0 <1.0 <1.0 <50 150 <1.0 <1.0 -- 1-4 b48M04 07/23/96 <1.0 <1.0 <1.0 <1.0 -- -- <1.0 <1.0 -- 1,4 b,j48M04 09/15/97 <1.0 <1.0 <1.0 <1.0 -- -- <1.0 <1.0 <1.0 1,4 b,k48M04 09/18/02 18 <0.5 <1.0 <1.0 <2.0 -- -- <1.0 <1.0 <1.0 <2.0 7

48M05 09/29/89 29 <0.3 <0.5 1.6 -- -- -- -- --48M05 09/29/89 3.0 <0.3 <0.5 <0.4 -- -- -- -- -- 1,5 a48M05 05/17/93 1.3 -- -- -- -- -- 0.6 -- -- 1,4,548M05 07/21/94 1.3 <1.0 <1.0 <1.0 <50 230 <1.0 <1.0 -- 1-4 b48M05 08/03/94 <1.0 <1.0 <1.0 <1.0 -- -- <0.5 <0.5 -- 1,4 b48M05 10/05/94 <1.0 <1.0 <1.0 <1.0 <50 2,100 <1.0 <1.0 -- 1-4 b48M05 09/07/95 2.2 <1.0 <1.0 <1.0 56 <100 <1.0 <1.0 -- 1-4 b48M05 07/24/96 1.2 <1.0 <1.0 <1.0 -- -- <1.0 <1.0 -- 1,4 b,j48M05 09/15/97 5.0 <1.0 <1.0 <1.0 -- -- <1.0 <1.0 <1.0 1,4 b,k48M05 09/04/02 41 <0.5 <1.0 <1.0 <2.0 -- -- <1.0 <1.0 <1.0 <2.0 7

TABLE 10-5. CONCENTRATIONS (µg/L) OF ORGANIC COMPOUNDS IN GROUNDWATER SAMPLES ST48, POWER PLANT FUEL SPILL, EIELSON AFB, ALASKA

Page 10-15




Well No.Date




MCLs 5 1,000 700 10,000 1,300ADEC 1,500ADEC 5 5 100 1,460


48M06 09/28/89 <0.2 <0.3 <0.5 <0.9 -- -- -- -- --48M06 09/28/89 <0.2 <0.3 <0.5 <0.4 -- -- -- -- -- 1,5 a48M06 05/17/93 <2.0 -- -- -- -- -- 0.6 -- -- 1,4,548M06 07/26/94 <1.0 <1.0 <1.0 <1.0 <50 140 <1.0 <1.0 -- 1-4 b48M06 08/03/94 <1.0 <1.0 <1.0 <1.0 -- -- <0.5 <0.5 -- 1,4 b48M06 10/05/94 <1.0 <1.0 <1.0 <1.0 <50 2,900 <1.0 <1.0 -- 1-4 b48M06 09/07/95 <1.0 <1.0 <1.0 <1.0 <50 <100 <1.0 <1.0 -- 1-4 b48M06 07/25/96 <1.0 <1.0 <1.0 <1.0 -- -- <1.0 <1.0 -- 1,4 b,j48M06 09/15/97 <1.0 <1.0 <1.0 <1.0 -- -- <1.0 <1.0 <1.0 1,4 b

48M07 10/09/89 3.6 <0.3 <0.5 <0.4 -- -- -- -- -- 1,5 a48M07 05/18/93 0.4 -- -- -- -- -- 2.1 -- -- 1,4,548M07 07/20/94 <1.0 <1.0 1.1 2.0 300 1,100 <1.0 <1.0 -- 1-4 b,f48M07 10/04/94 <1.0 <1.0 <1.0 <1.0 <50 520 <1.0 <1.0 -- 1-4 b48M07 03/16/95 6.3 15 7.8 28 360 390 1.8 <1.0 -- 1-4 b,g48M07 07/25/96 <1.0 <1.0 <1.0 <1.0 -- -- <1.0 <1.0 -- 1,4 b,f,j

48M08 05/27/93 130 -- -- -- -- -- -- -- -- 1,4,548M08 07/24/95 210 3,200 830 3,700 11,000 4,500 <25 <25 -- 1-4 b48M08 07/25/96 570 2,300 550 2,160 -- -- <1.0 <1.0 -- 1,4 b,f,j48M08 09/26/02 12 882 12,500 1,600 6,820 -- -- 2.2 <1.0 <1.0 754 7 m

48M08B 09/12/06 13 23 1,400 900 3,000 -- -- -- -- -- -- 7

48PP13 07/26/95 7,200 5,400 370 1,800 32,000 60,000 <25 47 -- 1-4 b48PP13 07/18/96 6,700 3,700 250 1,360 -- -- <20 61 -- 1,4 b,j

48PP28 07/26/95 64 540 480 4,100 14,000 180,000 <25 <25 -- 1-4 b48PP28 07/18/96 <1.0 150 280 3,600 -- -- <1.0 <1.0 -- 1,4 b,j

48PP101 07/26/95 250 11 160 960 7,800 58,000 <5.0 <25 -- 1-4

48PP102 07/18/96 6.2 5.0 160 660 -- -- <1.0 <1.0 -- 1,4 b,f,j

48PS1A 09/09/94 3 ND ND ND ND ND ND n48PS1B 09/09/94 6 ND ND ND 8.0 ND ND n48PS1C 09/09/94 9 ND ND ND 3.0 ND ND n48PS1D 09/12/94 12 ND ND ND 5.0 ND ND n

48PS2A 9/12,15/1994 4 900 4,900 500 4,000 32,000 370,000 n48PS2B 9/14,15/1994 7 110 280 90 460 5,000 17,000 n

48PS3A 09/10/94 6 12 ND ND ND ND ND n48PS3B 9/9,10/1994 9 13 ND 5.7 16 210 ND n48PS3C 09/10/94 12 ND ND ND 8.5 ND ND n48PS3D 09/12/94 15 ND ND ND ND ND ND n

48PS4A 09/09/94 6 140 59 130 206 4,200 110,000 n48PS4B 09/09/94 9 48 18 77 85 2,500 22,000 n48PS4C 9/9,10/1994 12 24 5.3 ND 25 800 3,600 n48PS4D 09/09/94 15 20 ND ND 12 130 ND n48PS4F 09/12/94 18 ND ND ND 5.0 ND ND n

Page 10-16




Well No.Date




MCLs 5 1,000 700 10,000 1,300ADEC 1,500ADEC 5 5 100 1,460


53M03 10/06/89 299 53 <0.5 1,990 -- -- -- -- --53M03 9/91 460 53 100 890 -- -- 1.0 <5.0 -- 5,6,8 a53M03 05/18/93 120 -- -- -- -- -- 0.4 -- -- 1,4,553M03 07/27/94 220 44 110 660 9,100 45,000 <1.0 2.3 -- 1-4 b53M03 10/05/94 460 11 27 164 3,000 56,000 <1.0 1.2 -- 1-4 b53M03 03/10/95 1.9 2.9 1.6 9.3 <100 230 2.1 <1.0 -- 1-4 b53M03 07/24/95 190 15 27 260 2,400 61,000 <1.0 1.5 -- 1-4 b,h

53M03 09/08/95 240 25 47 490 2,300 7,000 <1.0 <1.0 -- 1-4 b53M03 07/25/96 390 26 87 410 -- -- <1.0 <1.0 -- 1,4 b,j53M03 09/02/97 170 21 72 570 -- -- <1.0 <1.0 <1.0 1,4 b,k53M03 09/26/02 14 25 4.6 11 68 -- -- <1.0 <1.0 <1.0 62 7 l

Source: USAF 2007Complete references are provided in Appendix B.

Notes: a For additional compounds detected, see reference.b No compounds other than those listed or noted were detected above the reporting limits.d Sampled without purging, sampled after 10 gal. purged 16 March 1995. e Additional compounds detected: chloroethane - 3.2 µg/L.f Additional compounds detected: chloromethane - 2.7 µg/L, 48M07 - 5.6 mg/L, 48M08 - 1.8 mg/L, 48 PP102 - 2.2 mg/L.g Well was frozen, hot water was introduced and 3 gal. purged before sampling. h Additional compounds detected: 1,4 dichlorobenzene - 2.4 µg/L.i Additional compounds detected: chloroform - 58 µg/L, probably the result of laboratory dilution water contamination.j Methylene chloride detected in concentrations ranging from 2.6 - 84 ug/L, suspected to be the result of laboratory contamination.k Additional compound detected: chloromethane - 2 mg/L (48M01), 0.7 mg/L (48M04), 1.0 mg/L (18-3,48M05, 53M03).l Additional compounds detected (µg/L): 2-butanone (MEK) 55.8, isopropylbenzene 1.33, n-propylbenzene 1.30, 1,3,5-TMB 14.6,

1,2,4-TMB 33.0, and 4-isopropyltoluene 1.69.m Additional compounds detected (µg/L): chromomethane 1.02, chloroethane 2.67, 1,2-dobromoethane 4.84, isopropylbenzene 46.1,

n-propylbenzene 111.0, 1,3,5-TMB 469.0, 1,2,4-TMB 1600.0, sec-butylbenzene 4.91, 4-isopropyltoluene 3.80, n-butylbenzene 7.39.n

AAC Alaska Administrative CodeADEC Alaska Department of Environmental ConservationTCE Trichloroethene

DCA Dichloroethane DCE Dichloroethene TPH GRO Total Petroleum Hydrocarbons Gasoline Range OrganicsTPH DRO Total Petroleum Hydrocarbons Diesel Range Organics

MCL Maximum contaminant levelBold Bold text indicates concentration exceeds MCL.

Analytical Methods:1. 8020 3. ADEC 8100M 5. 8270 7. 8260 9. AK1012. ADEC 8015M 4. 8010 6. 8080 8. 8240 10. AK102

Analysis performed by on site gas chromotograph

Page 10-17

QAPP Worksheet #10 Title: Site Specific QAPP for Source Area ST48 Problem Definition Revision Number: 0 Revision Date: February 2012

Contract No. FA8903-08-D-8791-0026

Page 10-18



Page 10-19

1996 OU1 Pilot Study Monitoring Report (1997) Interim RAs were implemented in 1992 and included installing a VES to remove NAPL (USAF 1997b). This was not a viable means of remediation because much less recoverable NAPL was present than estimated during design of the system. During September 1992, a bioventing system was installed utilizing wells associated with the VES. The system was expanded in 1997 based on groundwater and vadose zone monitoring results, and new air injection and extraction points were installed. Draft Final Remedial Process Optimization (RPO) (2002) The goals of the RPO were to ensure that RAs were effectively meeting goals, to optimize the site remediation schedule, and to increase the cost effectiveness of the RAs (USAF 2002). RPOs follow a three phased approach: Phase I is a RPO scoping visit where data is collected and reviewed, and updates are given for ongoing RAs, Phase II is an RPO evaluation that determines a variety of optimization opportunities, Phase III is the implementation of the new or optimized systems (USAF 2002b). Phase I of Eielson AFB’s RPO recommended that within OU1, BTEX in soil gas should be monitored continuously to act as an indicator of remedial progress. Soil gas profiling should also take place to help determine when shutdown of a bioventing system could begin. Additionally, to optimize groundwater monitoring, the Phase I RPO recommended:

• Create a process to track trends in the groundwater contamination plumes, like a Monitoring and Remediation Optimization System (MAROS), to help determine sampling location and frequencies.

• Collect natural attenuation parameters to see if natural biodegradation processes are at

play.

• Measure the distance between the ground surface and the top of the well to help determine if frost-jacking has occurred.

Phase II of the RPO for ST48 consisted of soil gas surveys and soil sampling and analyses to confirm the extent of the cleanup performed to date (see Figures 10-4 through 10-6). Soil gas samples were collected using direct push sampling technology and were analyzed on-site for BTEX. Oxygen and carbon dioxide were also measured. Samples displayed low levels of BTEX in the vadose soils, and moderate levels of carbon dioxide in most locations. Eight confirmatory soil samples were collected and analyzed for BTEX, TPH-GRO, and TPH-DRO. BTEX levels were below OU1 ROD cleanup criteria, and one sample exceeded ADEC cleanup criteria for DRO.


Page 10-20

Phase II determined that the average contamination biodegradation rate had decreased from 3.3 milligrams per kilogram per day (mg/kg-day) to 1 mg/kg-day. Bioventing was lowering BTEX concentrations in soil vapor and the soil concentrations of BTEX and TPH-GRO were below cleanup levels. The bioventing system, as it existed in 2002, is presented in Figure 10-6. The 2002 Phase II RPO Evaluation concluded that the bioventing system had achieved the final remediation goals for soil. It should be noted that this conclusion appears flawed in that subsurface soil appears to have been collected down to 6 ft bgs only whereas previous data indicated the highest concentrations of COCs were below 10 ft bgs. The bioventing system was shut down on 3 September 2002 as recommended by the RPO evaluation. Monitoring was being performed when this report was written, including groundwater sampling for COCs and LTM under the SWMP. Operations and maintenance (O&M) was also conducted in accordance with the OU1 Work Plan. The recommended ICs were still being implemented when this report was written. The RPO recommended the following for Phase III: performance of annual free product compositional analyses; shutdown of the bioventing system; leaving the VES intact as a backup provision; and continued groundwater monitoring until the groundwater cleanup criteria are met. The RPO also recommended that soil gas and soil samples be collected at multiple locations and depths in the area north of the utilidor located parallel to Division Street, on both sides of the street (USAF 2002b). Five-Year ROD Reviews (1998, 2003, 2008) The three Five-Year Reviews at Eielson AFB included OU1 through 6 and Sitewide OU (USAF 1998c, 2004, and 2008). The progress of RAs from their respective RODs was reviewed to ensure the protection of human and environmental health. The reviews also identified issues and recommended solutions. 1998: This review found that RAs at OU1 and ST48 were operating within their design parameters and progressing toward remediation goals. Recoverable amounts of floating product were no longer present at ST48 and contaminant concentrations declined or stabilized in the groundwater. The review concluded that the remedies were protective of human and environmental health, and long-term operations (LTO) and maintenance of remedial activities should continue until cleanup goals are met (USAF 1998c). 2003: This review found that the remedy for ST48 was expected to be protective of human and environmental health. It was estimated through respiration tests that approximately 12,900 gallons of fuel biodegraded between 1992 and 2002 (USAF 2004).


Page 10-21

This review did identify an issue at ST48; while bioventing reduced BTEX concentrations within the zone of influence, BTEX concentrations increased north of Division Street, downgradient of the bioventing system. To solve this issue, it was recommended that the plume located north of the site be monitored and future groundwater monitoring events include sampling for BTEX at monitoring well 48M08, and downgradient monitoring well 18-6 (see Figure 10-3). Respiration testing, groundwater monitoring, and RPO Phase II results indicated that remedial action objectives (RAOs) were being achieved but the final remediation goals from the ROD had not been attained. Therefore, groundwater monitoring was recommended to continue until BTEX concentrations met the MCLs. The review also recommended that implementation of ICs and land use controls continue until the remaining RAOs are reached (USAF 2004). 2008: Bioventing operations at ST48 ended in 2002 and the system was decommissioned in 2003, because the goals set for remediation were met within the area of influence of the bioventing system. The system had effectively biodegraded fuels in the source area, decreasing BTEX concentrations in local groundwater. The potential was identified for the existence of soil BTEX concentrations exceeding the cleanup levels north of Division Street and outside of the area of influence of the system, see Figure 10-7 (USAF 2008). Groundwater monitoring and the implementation of ICs at OU1 were recommended to continue until further RAOs were achieved. In addition, the review recommended that the vapor intrusion pathway be evaluated to determine if the pathway presents an unacceptable risk. Overall, this review found that the current remedies for ST48 were performing as expected in protecting human health and the environment, and that the interim exposure pathways were being controlled (USAF 2008). Background Concentrations Site background is not available, but it is currently being developed. Once approved, site background data will be used to compare to investigation results. Regional and Site Geology The Base is located in the Tanana River Valley and is underlain by approximately 250-300 ft of unconsolidated fluvial and glaciofluvial sediments. Underlying the fluvial deposits is bedrock consisting of quartz-biotite schist, referred to as Birch Creek Schist. The developed portion of the Base consists of predominantly three soil types: sand and gravel fill, alluvium, and loess. Permafrost conditions occur in undeveloped locations within the valley but in areas of surface development only localized pockets of permafrost remain. At ST48, the upper 82 ft of the site are made up of sandy gravel, with lenses/layers of silt or silty sand present. The developed portion of the Base is in an area of low relief and featureless, with elevations averaging 550 ft above mean sea level (msl). The undeveloped east and northeast sides of the Base are built on bedrock hills with elevations as high as 1,125 ft above msl (USAF 1994c).


Page 10-22

Regional and Site Hydrology The upper unconfined aquifer extends from near the ground surface to a depth of about 200-300 ft. Horizontal groundwater gradients are reported to be 0.001 ft per ft at the Base. Groundwater in the developed portion of the Base typically occurs at a depth of approximately 6 ft bgs, with seasonal fluctuations of approximately 2 ft. The highest groundwater elevations occur during May and early June when the spring thaw occurs. Groundwater in the shallow aquifer flows to the north-northwest. Groundwater flow is influenced by surface water bodies, including Garrison Slough, and water supply wells. Groundwater is the principal source of potable and non-potable water at the Base and in nearby communities. The eastern portion of the Base is underlain by fractured bedrock that acts as an aquifer. The bedrock aquifer is not well characterized though it is known to have a more variable hydraulic conductivity and groundwater gradient than the alluvial aquifer. Near the Ski Hill facility, the bedrock aquifer has been encountered at depths ranging between 50 and 200 ft bgs. Groundwater flow, both horizontal and vertical, at ST48 is influenced by pumping from Well D (USAF 1994a). Monitoring wells 48M04, 48M05, and 48M06 are nested wells that are screened at approximately 12.5 to 22.5 ft bgs, 37.5 to 47.5 ft bgs, and 89.0 to 99.0 ft bgs, respectively. These nested wells permit measuring water levels and sampling groundwater from discrete depths within the aquifer near Well D. The Possible Classes of Contaminants and The Affected Matrices (Source Material) After a review of the history at this site, the possible classes of contaminants and potentially affected matrices are summarized in this section. The primary sources of potential contamination at ST48 consist of leaking underground fuel pipelines, PCB-containing transformers, and use of pesticides. The site may also have been impacted by ash deposition related to the operating Base power plant, and by the adjacent coal storage. Additionally, migration of contaminants from the off-site dry well at ST18 is possible via groundwater; this dry well impacted by leaching from the dry well located at ST18, which may have been used for disposal of chlorinated solvents and machine shop waste (which could include arsenic, cadmium, chromium, and lead). Based on these potential sources of contamination, COCs expected at the site could include petroleum hydrocarbons (GRO, DRO, and RRO), VOCs, PAHs, various metals, PCBs, and pesticides. Floating product (NAPL) has been observed at ST48 and is likely a continuing source of contamination to the groundwater. During previous site investigations, several chemicals were detected in excess of cleanup levels applicable at the time of the investigations. In groundwater, several VOCs (benzene, toluene, ethylbenzene, trans-1,2-DCE, TCE, tetrachloroethene [PCE], and 1,2-DCA), PAHs, petroleum hydrocarbons, and several metals were detected at significant concentrations, often exceeding the MCLs.


Page 10-23

According to the BRA, PAHs, pesticides, and metals were detected in surface soil at levels of concern, as were BTEX, petroleum hydrocarbons, and metals in subsurface soil. PCB 1254 was measured at a value below the laboratory detection limit in a subsurface soil sample during the 1989 sampling event. The RI/FS Management Plan (USAF 1993a) identified the need for determining the locations of any transformer sites in the vicinity of the Central Heating and Power Plant and indicated that the identified areas should be sampled for PCBs. This investigation was never carried out. Therefore PCBs remain a COC. The affected matrices could include surface soil, subsurface soil, groundwater, and air. There is no accessible surface water in the vicinity of ST48. Therefore, no surface water or sediment samples will be analyzed for this site.

The Rationale for Inclusion of Chemical and Nonchemical Analysis The following discussion assesses the potential for COCs to occur at ST48 by analytical suite, based on the sources of contamination and historical information. COCs carried through the ROD were BTEX and as such, VOCs will be included in surface and subsurface soil and groundwater. VOCs will also be analyzed in soil gas samples, if the soil source and plume delineation render this evaluation necessary. The air pathway will also be considered for VOCs. Re-evaluation of the ARARs, since the ROD was approved, has resulted in a requirement for additional analyses for GRO, DRO and RRO in surface and subsurface and groundwater samples. Metals and PAHs have been historically detected in surface and subsurface soils at the site, are potentially related to ash storage and other power plant operations. As a result, surface and subsurface soil and groundwater samples will be analyzed for target analyte list (TAL) metals and PAHs. The current extent of any floating product (NAPL) should also be investigated. Due to a detection of pesticides in a composite surface soil sample, conservatively, surface soil samples will also be analyzed for pesticides. Because PCB contamination from transformers is possible at ST48 and this has not been previously investigated, PCBs in surface soils will be retained for this investigation. Table 10-6 summarizes the analytical suites and affected matrices that will be analyzed in the QAPP.


Page 10-24

TABLE 10-6. ANALYTICAL SUITES AND POTENTIALLY AFFECTED MATRICES SOURCE AREA ST48

EIELSON AFB, ALASKA

Analytical Suite

Affected Matrix Surface

Soil Subsurface

Soil Groundwater Air

NAPL X DRO/GRO/RRO X X X -- PAHs X X X -- VOCs X X X1 X SVOCs -- -- -- -- Pesticides X -- -- -- PCBs X X -- -- Metals-TAL X X X -- Notes: 1 Included analysis for ethylene dibromide for water samples X = indicates samples will be analyzed for this suite of contaminants in the matrix indicated PAH = polycyclic aromatic hydrocarbon DRO = diesel range organics GRO = gasoline range organics RRO = residual range organics VOC = volatile organic compounds SVOC = semi-volatile organic compounds PCB = polychlorinated biphenyl TAL = target analyte list

Soil cores obtained during drilling will be collected from select depth intervals representative of different soil types encountered and analyzed to support fate and transport analysis. These data include:

• Soil physical properties including dry bulk density, porosity, and moisture content

• Fraction organic carbon to evaluate contaminant partitioning (distribution coefficient [Kd]) and retardation

• Sieve analysis to estimate permeability from select zones.

In addition, groundwater will be field analyzed for basic parameters, i.e., temperature, pH, specific conductance, oxidation-reduction potential, dissolved oxygen, and turbidity. Field test kits will be used to analyze groundwater samples for ferrous iron and manganese.


Page 10-25

The Potential Contaminant Migration Pathways Contaminant migration pathways have been identified based on the presence of chemicals of concern in surface and subsurface soil and groundwater. The primary potential exposure pathway is from the future unrestricted use of contaminated groundwater. The potential transport mechanisms at this site include:

• Dissolution of trapped NAPL in areas influenced by Well D pumping and historic dewatering activities.

• Dissolved-phase transport in an isolated portion of the vadose zone just upgradient of the former NAPL plume where constituents may be leached into soil moisture and migrate to the water table by infiltrating precipitation. This pathway is potentially complete.

• Dissolved-phase transport in the saturated zone, which is driven by groundwater flow within the aquifer.

• Vapor transport, in which the processes of diffusion and advection transport vapors

away from the source area. Information Concerning Various Environmental Indicators (Source-Receptor Interaction) The CSM depicts the relationship between the COCs and their sources, transport mechanisms, and ultimately, the receptors. The impacted media at the site include surface and subsurface soil, groundwater, and potentially air. Receptors could be exposed to any of the impacted media through a complete exposure pathway. Human Receptors: The CSM evaluates the following human health receptors, for current and potential future land use scenarios:

• Current/Future Military Residential—Although the site does not currently maintain residents, military residents are present on Eielson AFB. Conservatively, it is assumed military residents may be exposed to contaminants in soil via ingestion and direct contact. This receptor may be exposed to groundwater contaminants via ingestion, direct contact, and inhalation of volatiles in tap water. There is a possibility of exposure to soil and groundwater contaminants via inhalation of soil gas volatiles in indoor or outdoor air.


Page 10-26

• Current/Future Visitor—Current and future visitors may be exposed to surface soil at the site via incidental ingestion, dermal contact, and inhalation of volatiles in ambient air. This receptor also may be exposed to subsurface soil and groundwater contaminants via inhalation of soil gas volatiles in indoor or outdoor air. This receptor could also be potentially exposed to groundwater via ingestion, dermal exposure, or inhalation of volatiles in tap water.

• Current/Future Construction Worker—The construction worker may be involved in

activities that include installation/maintenance of subsurface utilities (trenching) and structures, excavation of building foundations, etc. Exposure may be to surface and subsurface soils via ingestion, dermal contact, and inhalation of volatiles in ambient air while working in a trench. This receptor may also be exposed to groundwater in areas where depth to groundwater is less than or equal to 15 ft bgs via incidental ingestion, dermal contact, and inhalation of while working in a trench.

• Current Site Employee—This receptor represents onsite workers consisting of military

or civilian and may be potentially exposed to subsurface soil and soil gas, and groundwater volatiles via migration to indoor or outdoor air. Additionally, this receptor is conservatively assumed to be exposed to shallow groundwater as a drinking water source.

• Future Residential—The land use at Eielson AFB is not reasonably anticipated to

change under future use scenarios. However, there is a potential for residential development and it is conceivable that in the future the USAF may allow the property to be used for residential purposes as allowed by zoning restrictions. For this reason, a future onsite residential scenario is included in the CSM. This future receptor may be exposed to surface and subsurface soil via incidental ingestion or dermal contact. This receptor also may be exposed to subsurface soil and groundwater contaminants via inhalation of soil gas volatiles in indoor or outdoor air. Additionally, this receptor could be exposed to groundwater contaminants via ingestion, dermal exposure, or inhalation of volatiles.

• Future Industrial/Commercial Worker—This worker conducts typical operational

activities in an outdoor setting and is exposed to surface soil via incidental ingestion and dermal contact, and inhalation of volatiles in ambient air. Additionally, this receptor is conservatively assumed to use shallow groundwater as a drinking water source where it is available for commercial or industrial purposes.

Contaminants are not considered to bioaccumulate and are, therefore, not a risk to upper-trophic level organisms. There are no accessible surface water bodies within the immediate vicinity of the site that would be considered habitat to aquatic receptors.


Page 10-27

Ecological Receptors: Evaluation of ecological risks for the site is not necessary because pathways to receptors are not complete based on the following information:

• Sensitive Environments—There are no critical habitats within the source area.

• Historical/Cultural Resources—There are no documented cultural resources at the source area as the historical and current land use has been military.

Figure 10-8 presents the detailed CSM for Source Area ST48 illustrating the impacted media, exposure pathways, and potential current and future receptors. The CSM constitutes the basis for developing the sampling strategy and technical approach which follow in Worksheet #11, with additional details provided in Worksheet #14. Project Decision Conditions (“If..., then...” statements): The conditions that would cause the decision maker to choose among alternative response actions are stated below:

1. If soil analytical data collected from the source area are below the Final Remediation Goals as established in the ROD (USAF, 1994a) for BTEX and below the soil screening levels for all other compounds, then delineation of the extent of soil contamination in the source area will be considered complete; if not, soil screening and sampling will be expanded to facilitate source delineation. For metals, if a background concentration is available for comparison, then the comparison will be made to the higher of the background or the soil screening levels. If a background concentration is not available, the comparison will be made directly to the soil screening level.

2. If groundwater analytical data collected from discrete sample points are below the Final Remediation Goals for BTEX or the groundwater screening levels for all other compounds, then delineation of the extent of the groundwater plume will be considered complete; if not, additional groundwater screening and sampling data will be collected to the extent feasible to complete vertical and horizontal groundwater plume delineation. For metals, if a background value is available, the comparison will be made to the highest of the background value and the groundwater cleanup level. If a background concentration is not available, the comparison will be made directly to the groundwater cleanup level.

3. Field screening with Oil Screen Soil™, or equivalent, will be used to indicate the

presence of NAPL. If NAPL is detected, then the need for additional remedial activities for NAPL will be evaluated. Trapped NAPL will be evaluated below the water table in areas where NAPL is suspected to ensure no residual NAPL exists below the water table in areas formerly influenced by well pumping and/or dewatering (i.e., north of


Page 10-28

intersection of Industrial Drive with Division Street). If NAPL is not detected, then NAPL will not be considered a continuing contaminant source at the site.

4. If air or soil gas analytical data collected from buildings on the site (if applicable) indicate

the risk of vapor migration potentially exists, then vapor intrusion will be considered a complete pathway and its risk will be evaluated according to the ADEC Draft Vapor Intrusion Guidance for Contaminated Sites (ADEC 2009b).

ST48

Figure 10-1: Location of Source Area ST48, Eielson AFB, Alaska

Legend

Source Area ST48

´0 0.2 0.4 0.6 0.80.1

Miles

Figure 10-2: Site Features, ST48, Eielson AFB, Alaska

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GARRISON SLOUGH <--- Direction of Flow

3213

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ST11

INDUSTRIAL DRIVE

DIVIS

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ARCTIC AVENUE

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18-1

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48PS748M03

48PS1 48SG6

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48SG1

48SG2

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48PS6

53M03

48PS4

48SG4

48SG548PS548PS3

48PS2

48M01

48M02

48M0648M05

48M04

48M08

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48PP1348PP68

48PP05 48PP66

48PP6548PP1248PP11

48PP63

48PP03

48PP64 48PP01

48PP09

48SG10

48PP28

48M08B

48SVM03

18PWM01

48PP102

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ST48-UNKNOWN(01)

48PP67

48PP1048PP06

48PP08

ST48

ST18

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3423

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6203

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6210

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6203

3416 3417 341862032 6203462033

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6204

8985TEMP

8984TEMP

0 75 15037.5Feet

Legend@A Monitoring Well

&< Monitoring Well, decommissioned

Drywell, removed

D Fence Line

Abandoned POL Pilelines

Source Area Boundary per OU1 ROD (approximate)

Probable Location of Drywell

Structure, former location

Structure, existing µ

Path: C:\Users\jharding\Desktop\EA\1456026 Eielson 2011\GIS\ST48\ST48QAPP2011_DraftFinal_V2\Fig 10-2 Site Features ST48.mxd

Groundwater Direction

From AR240

Coal Piles

48PP28

48PP101

48PP102

48PP13

48M04

48M05

48M06

53M03

48MO8

18-648M07

48M01

ST48

48MO8B

18-6B

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INDUSTRIAL DRIVE

DIVI

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48SB24 48SB23 48SB22 48SB2148SB20

48SB19 48SB18

48SB17

48SB16 48SB1548SB14

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48SB11

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48SB09

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ST48

Figure 10-4: 1988/1989 and 1993 Soil Sampling Summary, ST48, Eielson AFB, Alaska

´ Legend&< Monitoring Well, plugged@A Monitoring WellD Fence Line


Composite Pesticide Sampling Location# Test Pit Location

Soil Boring LocationTPH above 100 mg/kg

0 50 100 150 20025Feet

³

Location Contaminant Result(ug / kg)1

NEW WELL Anthracene 400(48M08) Benzo(a)anthracene 970

Benzo(a)pyrene 980Benzo(b)fluoranthene 950Benzo(ghi)perylene 540Benzo(k)fluoranthene 870Chrysene 1,100Fluoranthene 2,200Indeno (1,2,3-cd)pyrene 510Phenanthrene 1,500Pyrene 2,000

53M03 2-Methylnaphthalene 46,000Naphthalene 16,000PCB-1254 ND

COAL PILE TPH-diesel 11,0001 All results in ug / kg

1993 Soil Sampling Results (USAF 1994b)

SampleID

Depth(bgs, ft) mg / kg1 Sample

IDDepth

(bgs, ft) mg / kg1

48SB01 0-1.5 20 48SB14 0-2.0 143.0-4.5 ND 3.0-4.5 ND6.0-8.0 120 6.0-8.0 ND

48SB02 0-1.5 ND 48SB15 0-1.5 5503.0-4.5 ND 0-1.5 2705.0-7.0 32,000 3.0-4.5 51

48SB03 0-1.5 ND 6.0-8.0 ND4.0-5.5 33 48SB16 0-1.5 280

10.0-12.0 3,900 3.0-4.5 1313.0-14.5 12,000 6.0-8.0 ND

48SB04 4.0-5.5 ND 6.0-8.03 ND8.0-9.5 ND 48SB17 3.0-4.5 ND

11.0-13.0 ND 8.0-9.5 ND48SB05 1.0-2.5 ND 10.5-12.5 ND

4.0-6.0 ND 48SB18 0-1.5 4608.0-9.5 ND 4.0-5.5 ND

11.0-12.5 ND 8.0-9.5 ND48SB06 0-2.0 ND 10.5-12.5 ND

3.0-4.5 ND 48SB19 0-1.5 ND5.0-6.5 94 4.0-5.5 ND

10.0-12.0 150 8.0-9.5 ND10.0-12.03 76 10.5-12.5 ND

48SB082 0-1.5 160 10.5-12.53 ND3.0-4.5 ND 48SB20 3.0-4.5 ND6.0-8.0 ND 8.0-9.5 ND

48SB09 0-1.5 ND 10.5-12.5 ND3.0-4.5 13 48SB21 8.0-9.5 ND6.0-8.0 ND 10.0-11.5 ND

48SB10 0-2.0 32 14.0-15.5 ND4.0-5.5 43 48SB22 8.0-9.5 228.0-9.5 82 10.0-11.5 77

11.0-12.5 1,700 13.0-14.5 1348SB11 0-1.5 ND 48SB23 8.0-9.5 65

3.0-4.5 ND 10.0-11.5 ND5.5-7.5 ND 12.5-14.0 ND

48SB12 0-1.5 26 48SB24 0-1.5 533.0-4.5 ND 5.0-6.5 145.5-7.5 2,600 9.0-10.5 ND

48SB13 0-1.5 13 11.0-12.5 ND3.0-4.5 ND5.5-7.5 ND

1989 TPH Concentrations for Boring Samples (USAF 1992a)

1 All results in mg / kg2 48SB07 was not drilled because HLA was unable to obtain utility clearance.3 Duplicate sample.

Sample ID Depth (bgs, ft) Contaminant1 Result2

(mg/kg)48M01SA 5-6.5 TPH 32748M02SA 0-1.25 TPH 14248M03SA 10-11.25 TPH 89.048M04SA 10-10.5 TPH 38.6

2-Ethylhexyl phthalate (bis) 1.248DPS01 10-10.5 TPH 76.048M06SA 2-4 TPH 46.948TP03SA 4.5-5.5 TPH 63.148TP04SA 13-14.5 TPH 13000

2-Methylnaphthalene 42Naphthalene 21

53M03SA 10-11.3 TPH 7402-Methylnaphthalene 3.0Naphthalene 1.4Di-n-octylphthalate 0.70Fluorene 0.21Phenanthrene 0.11PCB-1254 0.24

2 All results in mg / kg1 TPH = total petroleum hydrocarbons

Note: All samples tested for 2-ethylhexyl phthalate (bis), 2-methylnaphthalene, naphthalene, di-n-octylphthalate, fluorene, phenanthrene, TPH, and lead. This table presents results for these contaminants. If no sample is listed, then the result is ND for these contaminants. Exception is that 53M03SA was the only sample tested for PCB-1254.Note: All samples also tested for benzene, ethylbenzene, toluene, xylenes (total) (BTEX), chlorobenzene, and lead. BTEX and chlorobenzene detected in 48TP04SA and xylenes detected in 53M03. Lead detected in 9 of 13 samples. Exception is that 53M03SA was the only sample not tested for lead.

1988 Soil Sampling Results (USAF 1989a)

Path: C:\Users\jharding\Desktop\EA\1456026 Eielson 2011\GIS\ST48\ST48QAPP2011_DraftFinal_V2\Fig 10-4 1988-1989 and 1993 Soil Sampling Summary.mxd

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INDUSTRIAL DRIVE

DIV

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SB208

SB207SB205

SB204

SB206

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SB202SB201

ST48

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8985TEMP

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Figure 10-5: 2002 Soil Sampling Locations and Detected Concentrations, ST48, Eielson AFB, Alaska

´

Legend

&= Soil Boring Location

@A Monitoring Well

D Fence Line


NOTE:BTEX concentrations at all soil boring locationsidentified were below levels specified by theOU1 ROD to protect groundwater (USAF2002b).

0 40 80 120 16020Feet

³

Sample IDSample Depth

(bgs)Contaminants Result Units

SB201 3' TPH DRO 16 mg/Kg

6' TPH DRO 73 Q mg/Kg

SB202 3' TPH DRO 1.1 F mg/Kg

6' Ethylbenzene 0.19 mg/Kg

6' TPH GRO 9.8 F mg/Kg

6' TPH DRO 12 mg/Kg

SB203 2.5' TPH DRO 8.3 mg/Kg

5' TPH DRO 14 Q mg/Kg

SB204 6' TPH DRO 0.89 F mg/Kg

SB205 3' TPH DRO 1.5 mg/Kg

6' Ethylbenzene 0.089 F mg/Kg

6' TPH GRO 20 mg/Kg

6' TPH DRO 1,300 Q mg/Kg

SB206 2.5' TPH DRO 15 mg/Kg

6' Ethylbenzene 0.13 mg/Kg

6' TPH GRO 0.28 mg/Kg

6' TPH DRO 52 mg/Kg

SB207 2.5' TPH DRO 1.9 mg/Kg

5' TPH GRO 11 mg/Kg

5' TPH DRO 11,000 Q mg/Kg

SB208 3' TPH DRO 1 F mg/Kg

5' TPH DRO 3.4 mg/Kg

Q = Elevated Reportng Li mi t�

F = Trace Level

Q = Elevated Reporting Limits

F = Trace Level

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SGS218<5 µg/L

SGS217<5 µg/L

SGS215<5 µg/L

SGS214<5 µg/L

SGS213<5 µg/L

SGS212<5 µg/L

SGS211<5 µg/L

SGS210<5 µg/L

SGS209<5 µg/L

SGS208<5 µg/L

SGS207<5 µg/L

SGS206<5 µg/L

SGS205<5 µg/L

SGS204not sampledSGS203

<5 µg/L SGS202<5 µg/L

SGS201<5 µg/L

INDUSTRIAL DRIVE

DIVIS

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STRE

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ST48

6203

62035

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6210

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6211

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6204

8985TEMP

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Figure 10-6: 2002 Soil Gas Sampling Locations and Detected Concentrations, ST48, Eielson AFB, Alaska

´Legend! Soil Gas Survey Point<1 BTEX Concentration (USAF 2002b)D Fence Line


0 40 80 120 16020Feet

³

UTILIDORMANHOLE

UTILIDORMANHOLES

UTILIDOR

UT

ILI D

OR

Military Residential Visitor Construction

Worker Site Employee Subsistance Residential Visitor Construction Worker

Industrial/Commercial Subsistance

Ingestion ◑ ◑ ◑ ◑ ◌ ◑ ◑ ◑ ◑ ◌Direct Contact ◑ ◑ ◑ ◑ ◌ ◑ ◑ ◑ ◑ ◌

CURRENT RECEPTORS FUTURE RECEPTORS

HUMAN HEALTH RECEPTORS

ContaminationSources

Release Mechanisms Impacted Media

Migration to Subsurface Soils

Transport Mechanisms Exposure Media Exposure

Route

SoilSurface Soil1

and Uptake ◑ ◑ ◑ ◑ ◌ ◑ ◑ ◑ ◑ ◌ Inhalation

Fugitive Dust ◑ ◑ ◑ ◑ ◌ ◑ ◑ ◑ ◑ ◌

Inhalation of VOC in tapwater ◑ ◑ ◑ ◑ ◌ ◑ ◑ ◑ ◑ ◌

Ingestion ◑ ◑ ◑ ◑ ◌ ◑ ◑ ◑ ◑ ◌Direct Contact

and Uptake ◑ ◑ ◑ ◑ ◌ ◑ ◑ ◑ ◑ ◌

Ingestion of wild foods ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌

Indoor Inhalation ◑ ◑ ◑ ◑ ◌ ◑ ◑ ◑ ◑ ◌Outdoor

Inhalation ◑ ◑ ◑ ◑ ◌ ◑ ◑ ◑ ◑ ◌

The sources at Area ST48 have been

identified as a buried multi-fuel pipeline, power plant operations, ash and

coal piles, and an upgradient well at ST18.

Leaks in the pipeline



Subsurface Soil2

Groundwater


AirVolatilization

Migration to Groundwater

Transport Mechanisms

Fl

Exposure Media Exposure Route

Groundwater

Biota

Soil

Runoff/ Erosion

Uptake byPlants/Animals

Surface Soil1

x

Ingestion ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌Direct Contact ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌

Ingestion ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌Direct Contact ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌ ◌

● Complete Pathway◑ Potentially Complete Pathway◌ Incomplete Exposure Pathway (no expected exposure)- Not Applicablex Incomplete Pathway







Subsurface Soil2

Groundwater


AirVolatilization


INTEGRATED CONCEPTUAL SITE MODEL FOR ST48 Eielson Air Force Base, Alaska.

February 2012

Source: ADEC Guidance on Developing Conceptual Site Models October 2010


Flow to surface

water body


Groundwater

Surface Water3

Sediment

Biota

Notes:1- Surface Soil 0-2 ft bgs2-Subsurface Soil >2 ft3-There are no surface water bodies within the boundaries of this source area.

Soil

Runoff/ Erosion


Surface Soil1

Flow to sediment

x

x

x

Figure 10-8: Conceptual Site Model, ST48, Eielson AFB, Alaska







Subsurface Soil2

Groundwater


AirVolatilization


INTEGRATED CONCEPTUAL SITE MODEL FOR ST48 Eielson Air Force Base, Alaska.

February 2012

Source: ADEC Guidance on Developing Conceptual Site Models October 2010


Flow to surface

water body


Groundwater

Surface Water3

Sediment

Biota

Notes:1- Surface Soil 0-2 ft bgs2-Subsurface Soil >2 ft3-There are no surface water bodies within the boundaries of this source area.

Soil

Runoff/ Erosion


Surface Soil1

Flow to sediment

x

x

x

QAPP Worksheet #11 Title: Site Specific QAPP for Source Area ST48 Project Quality Objectives/ Revision Number: 0 Systematic Planning Process Statements Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 11-1

QAPP WORKSHEET #11 PROJECT QUALITY OBJECTIVES/SYSTEMATIC PLANNING PROCESS STATEMENTS An integral part of a UFP QAPP is the formulation of the project quality objectives (PQOs). The PQOs incorporate the elements of an USEPA Data Quality Objectives (DQOs) process, which in turn consists of a series of seven planning steps that are designated to ensure that the type, quantity, and quality of the environmental data used in the decision making are appropriate for their intended application. The DQOs process is outlined in the USEPA 2006 guidance document entitled “Guidance on Systematic Planning Using the Data Quality Objectives Process” (USEPA/240/B-06/001, February 2006) (USEPA 2006). Procedures on documenting deviations to the planning documents are provided in Worksheet #32 of the QAPP. The PQOs for this site are defined by covering the following elements: (1) who will use the data; (2) what will the data be used for; (3) what type of data are needed; (4) matrix; (5) how “good” the data need to be in order to support the environmental decision; (6) how much data are needed; (7) where, when, and how should the data be collected/generated; (8) who will collect and generate the data; (9) how will the data be reported; and (10) how will the data be archived. The specific QA/QC requirements developed for the site are consistent with those presented in the DoD Quality Systems Manual (QSM), Version 4.2 (DoD 2010). WHO WILL USE THE DATA? The data will be used by the Eielson AFB team, consisting of USAF, state, and federal agency representatives. WHAT WILL THE DATA BE USED FOR? The data will be used to update the CSM, characterize the nature and extent of contamination, and evaluate potential risks to human health associated with exposures to surface soil, subsurface soil, groundwater, and air (as necessary). Although a comprehensive risk assessment is not planned at this time, the results of this investigation may indicate the need for further risk assessment. WHAT TYPE OF DATA ARE NEEDED? (target analytes, analytical groups, field screening, onsite analytical or offsite laboratory techniques, sampling techniques) Table 11-1 summarizes the sampling program (including target analytes, analytical groups and sampling techniques) that is proposed to satisfy the scope of the investigation. Field screening for groundwater quality will also be performed by an onsite analytical laboratory.


Page 11-2

Matrices The matrices for samples collected at Source Area ST48 are groundwater, soil, and potentially air. HOW “GOOD” DO THE DATA NEED TO BE IN ORDER TO SUPPORT THE ENVIRONMENTAL DECISION? Laboratory analytical data must be determined to be useable and reporting limits (RLs) must be at or below evaluation criteria when possible. Collected data needs to be of adequate quality to make the decisions established for this site and will be compared initially to Project Action Limits or evaluation criteria that are specified in Worksheet #15. The reference limits and evaluation criteria are shown in Worksheet 15; Table 15-1 for soil, Table 15-2 for groundwater, and Tables 15-3a and 15-3b for air samples (indoor air and sub-slab/soil gas, respectively). Analytical methods were selected during the planning process to ensure that the RLs for the various analytes are adequate to make the project decisions. Any compounds for which the RLs are above the action levels are discussed in Worksheet #15. Field instrumentation will be selected to cover the range of variation for the parameters being measured (refer to Worksheet #22). Additional detail on sampling methodology, analyses, and equipment is provided in subsequent QAPP worksheets. The sample concentrations will be compared to the performance measurement criteria shown in Worksheet #12 to determine usability to meet the goals of the investigation. HOW MUCH DATA ARE NEEDED? (Number of samples for each analytical group, matrix, and concentration.) Because a Triad approach is planned for use, this is not a prescriptive plan, but rather a systematic plan that outlines the use of dynamic work strategies and real-time measurements to reach the goals of the investigation. In general, the approach to characterize nature and extent (and residual impacts post-remediation) at ST48 will include:

• Soil sampling in localized area(s) for analysis by an offsite laboratory to delineate soil impacts with definitive data;

• Groundwater sampling from direct push borings for analysis by a field laboratory and

offsite laboratory with screening level and definitive data, respectively, to delineate solute impacts;


Page 11-3

• Review soil and groundwater data collected during this event to determine if either the indoor or outdoor air exposure pathway requires evaluation. If appropriate, the evaluation of this pathway and the decision making for sampling will be determined following the steps outlined in the ADEC Vapor Intrusion Guidance (ADEC 2009);

• Soil gas and air sampling to evaluate the vapor intrusion pathway, if needed;

• Installation of permanent monitoring wells in key locations for collection of definitive

groundwater data; and

• Establishment of long-term groundwater monitoring regimen to establish concentration trends and evaluate plume stability.

The technical approach for each stage of the field work is described in detail in Worksheet #14. The sampling rationale is also discussed in Worksheet #17. For this reason, Table 11-1 contains both sampling information that is to a large extent certain (such as collection of water samples from existing wells), but also approximate information such as to install up to five new shallow monitoring wells for long-term monitoring of the plume. This lack of specificity in number of sampling points rests on the fact that progressive data collection (such as using a field screening technique) will better support installation of permanent wells. Although the numbers and locations of field activities cannot be specified a priori, Table 11-1 aggregates the critical information necessary for the field team to implement the QAPP, such as matrix, concentration levels, sampling tools and SOPs to be implemented, rationale for sampling, and the analytical suites for which the samples will be analyzed. WHERE, WHEN, AND HOW SHOULD THE DATA BE COLLECTED/GENERATED? Where: Groundwater samples will be collected from the four existing monitoring wells identified on Figure 11-1. Table 11-2 provides well construction information for these wells. Locations for installation of permanent monitoring wells will be discussed/decided upon with stakeholder input, following review of results from the direct push soil and groundwater plume delineation activities. Direct push soil and groundwater samples will be collected within the grid area depicted on Figure 11-1. The grid was established to allow easier description of sample locations during completion of the field program. Each grid area (50-ft spacing) is identified by row and column designators so that reference to direct push locations during step outs are readily identifiable to decision makers. Only selected locations within the grid will be sampled; locations will be determined in the field using the Triad approach. If site conditions indicate the potential for vapors to migrate to indoor air, soil gas and potentially indoor and outdoor air samples will be collected in the vicinity of occupied buildings present within the contaminant plume area, in accordance with ADEC Vapor Intrusion Guidelines (ADEC 2009). Again,


Page 11-4

because dynamic work strategies and real-time measurements will be used, not all locations could be depicted on these figures. When: Sampling will be initiated as soon as this QAPP is approved and will proceed according to the project schedule shown on Worksheet #16. How: The sampling design and rationale is outlined in detail in Worksheet #17. The design is presented for each medium in Worksheet #11, Table 11-1. The table includes the following information: sample media, sample numbers and identifications, analytical suites, QC samples, sampling tools, and sampling rationale. WHO WILL COLLECT AND GENERATE THE DATA? The EA team will collect the field data and environmental samples. TestAmerica and the Triad Environmental Solutions, Inc. field laboratory will analyze the environmental samples and generate laboratory results. HOW WILL THE DATA BE REPORTED? Interim results from the initial mobilizations for data collection will be reported as memoranda transmitted via email to the stakeholders. These memoranda will be used to make the next decision in the dynamic investigation approach. A report will be prepared at the conclusion of the field operations and will consist of a comprehensive compilation of the data collected under this project. The report will include a detailed narrative of each field activity and a summary of the sampling and analyses conducted. Site drawings, figures, laboratory analytical reports, field forms, survey coordinates, and photographs documenting field activities will be included as attachments to the report. The analytical data will be reported in Excel™ summary tables to facilitate data analysis. Ultimately, the report will be comprehensive in nature and no additional sources of information will be necessary to capture the full extent of the field operations and data collected. HOW WILL THE DATA BE ARCHIVED? The data will be saved in existing electronic formats (i.e., portable document format) in project archives at the contractor’s office. Electronic deliverables will be uploaded electronically in the AFCEE database. Additional information, such as digital photographs, will be stored in an electronic format that is efficiently transmittable. Data compression, image quality, and content will be in conformance with AFCEE deliverable requirements. Moreover, analytical data should


Page 11-5

meet the Environmental Restoration Program Information Management System (ERPIMS) data deliverable requirements for this Task Order. The field and laboratory data will be recorded and entered into a computerized submission format in accordance with the most recent version of the ERPIMS Data Loading Handbook. The electronic data deliverables and the laboratory data reports will be collected in project archives in existing electronic formats provided by the analytical laboratory. These will include the executable files delivered by the laboratory.


Page 11-6


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Figure 11-1: Benzene and NAPL Plumes with Potential Direct Push Sample Area, ST48, Eielson AFB

´

Legend

Potential Direct Push Sampling Area 50 foot grid spacing

D Fence LineApproximate Benzene Plume Based on Historic Groundwater Results (See Figure 10-2)Approximate Limit of NAPLOccurrence Based on Thickness Observed from 1988-1998Source Area Boundary per OU1 ROD (approximate)

0 50 100 150 20025Feet

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Proposed Initial Direct Push Sample Location Monitoring Well, Existing Monitoring Well or Sampling Point, Decommissioned

TABLE 11‐1 PROPOSED FIELD SAMPLING PROGRAM

SOURCE AREA ST48 EIELSON AIR FORCE, ALASKA

Sample Location Total Depth (ft bgs)

Point ID (Location ID)

Sample ID (the last digits for soil samples identify

the bottom of the sampling interval)

Matrix Sample Type

Sampling Method/Tool

Sampling/Measurement

Frequency

Sample Depth (ft bgs)

Expected Concentration

Level

VOC

s - 8

260B

1

VOC

s - T

O-1

5 1

VOC

s - T

O-1

5 SI

M 1

GR

O/ D

RO

/ RR

O 2

(AK

101

,102

,103

)

EDB

- 80

11

PAH

s 82

70C

SIM

Pest

icid

es 8

081A

PCB

s - 8

082

TAL

Met

als

60

20/ 7

471A

Bul

k D

ensi

ty

AST

M D

7263

-09

Poro

sity

- AST

M

D68

36-0

2(08

)

TOC

- 90

60

Moi

st. C

onte

nt

AST

M D

7263

-09

Gra

in S

ize-

AST

M

D42

2-63

(07)

VOC

s - 8

265

Fe /

Mn

Test

Kit

NA

PL D

ye K

it

PID

pH

Con

duct

ivity

Tem

pera

ture

DO

OR

P

Turb

idity

Sampling Rationale EA Field SOP

Baseline Groundwater Sampling

48M04 48M04 1 0 0 1 1 1 0 0 1 0 0 0 0 0 0 Y N Y Y Y Y Y Y Y

48M05 48M05 1 0 0 1 1 1 0 0 1 0 0 0 0 0 0 Y N Y Y Y Y Y Y Y

48M06 48M06 1 0 0 1 1 1 0 0 1 0 0 0 0 0 0 Y N Y Y Y Y Y Y Y

48M07 48M07 1 0 0 1 1 1 0 0 1 0 0 0 0 0 0 Y N Y Y Y Y Y Y Y

4 0 0 4 4 4 0 0 4 0 0 0 0 0

Field QC Samples

Field Duplicates (10 percent rounded up) Various

Same as the sample it duplicates

Blind Sample - To be assigned a fictitious well ID Water Low flow pump 10% rounded up


Low to Medium 1 0 0 1 1 1 0 0 1 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA Field QC - indicative of precision Same as for sample duplicated

Trip Blanks for water samples (assume 2 coolers) NA NA TBB-01 and TBB-02

(trip blank for Baseline) Water Laboratory-prepared One per cooler NA Low 2 0 0 2 0 0 0 0 0 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA Field QC - indicative of accuracy

Equipment Blank 3 NA NA EBB-01(EB for Baseline) Water Grab One per event NA Low 0 0 0 0 0 0 0 0 0 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA Field QC - indicative of accuracy

(use of disposable equipment planned)

MS/MSDs (5 percent rounded up) NA Various Same as the monitoring

well associated with it Water Low flow pump 5% rounded upSame as the

sample with which it is associated

Low 1 0 0 1 1 1 0 0 1 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA Laboratory QC - indicative of precisionSame as primary sample, only extra volume collected.

Same as for associated sample

8 0 0 8 6 6 0 0 6 0 0 0 0 0Soil Source Delineation

0 - 2 ft Low to Medium T 0 0 T 0 T T 0 T 0 0 0 0 0 0 N N Y N N N N N N

2 ft - Water table Low to High T 0 0 T 0 T 0 0 T 0 0 0 0 0 0 N N Y N N N N N N

Variable Capillary Fringe Medium to High 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 N Y N N N N N N NA soil sample will be collected from the capillary fringe in borings in and near the source area for field screening for NAPL.

Water table - 15 ft Water table - 15 ft Low 0 0 0 0 0 0 0 0 0 5 5 5 5 5 0 N N N N N N N N N Soil samples for physical testing will be collected from non-

contaminated areas surrounding the benzene plume.

T 0 0 T 0 T T 0 T 5 5 5 5 5Field QC Samples

Field Duplicates (10 percent rounded up)

0 ft - Water Table


Blind Sample - To be assigned a fictitious

sample ID Soil Direct Push Sampler 10% rounded up


Low to High T 0 0 T 0 T T 0 T 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA Field QC - indicative of precision Same as for sample duplicated

Trip Blanks for soil samples (assume 4 days of sampling and 2 coolers per day)

NA NATBSS-01 through

TBSS-04 (TB for soil samples)

Methanol Laboratory-prepared One per cooler NA Low 8 0 0 8 0 0 0 0 0 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA Field QC - indicative of accuracy

Equipment Blanks (assume 4 days of sampling by direct push)

NA NA

EBSS-01 through EBSS-02

(equipment blank for soil samples)

Water Grab One per day NA Low 4 0 0 4 0 4 4 0 4 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA Field QC - indicative of accuracy

MS/MSDs (5 percent rounded up) NA Various Same as the sample

associated with it Soil Direct Push Sampler 5% rounded upSame as the


Low T 0 0 T 0 T T 0 T 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA Laboratory QC - indicative of precisionSame as primary sample, only extra volume collected.


T 0 0 T 0 T T 0 T 5 5 5 5 5

Field TestingAnalytical Suite/Method

Existing Monitoring Wells See Table 11-2 Water Grab

Soil sample locations will be selected within the source area to confirm current concentrations. Direct push sampling locations will be stepped outward until evidence of contamination is not detected (including benzene less than or equal to 1 ug/L in associated direct push groundwater samples based on field laboratory results). Two samples will be collected per borehole. One surface soil sample (0 to 2 ft) and one subsurface soil sample (2 ft to the water table) will be collected from the most impacted depth, as evidenced by PID readings.

SOP-001SOP-002SOP-004SOP-005SOP-011SOP-025SOP-047

Baseline Groundwater Sampling - Environmental Samples

Total Samples for Baseline Well Sampling

QC

Direct Push Boring Soil Samples

0 ft - Water table

Point location and number of

samples to be determined by

Triad approach; for planning

purposes, assume approximately 30

locations and samples



Triad approach.

Grid node ID-sample depth-date (DDMMYY)

Example: At location A4 for a sample collected from 8' on 10/9/11 the sample

ID isA4-08-100911

Soil Grab Direct Push Sampler Once

SOP-001SOP-002SOP-004SOP-005SOP-010SOP-013 SOP-036SOP-043SOP-048

Low flow pump Once

Middle of the submerged

screened zone. Refer to screened interval on Table 11-2. For water

table wells, collect sample from the upper few feet of

water table.

Soil Source Delineation - Environmental Samples

Total Samples for Soil Source Delineation

QC SOP-001SOP-002SOP-004

SOP-001SOP-002SOP-004

Low to Medium

These wells will be surveyed to create a common reference. Wells will be gauged to determine the depth to water and the direction of groundwater flow. The analytical data will be used to establish a baseline for groundwater quality at the site prior to field activities and to guide the placement of the initial direct push sampling locations. Note well screen interval on Table 11-2.

Page 1 of 3







Matrix Sample Type



Frequency



Level

VOC

s - 8

260B

1

VOC

s - T

O-1

5 1

VOC

s - T

O-1

5 SI

M 1

GR

O/ D

RO

/ RR

O 2

(AK

101

,102

,103

)

EDB

- 80

11

PAH

s 82

70C

SIM

Pest

icid

es 8

081A

PCB

s - 8

082

TAL

Met

als

60

20/ 7

471A

Bul

k D

ensi

ty

AST

M D

7263

-09

Poro

sity

- AST

M

D68

36-0

2(08

)

TOC

- 90

60

Moi

st. C

onte

nt

AST

M D

7263

-09

Gra

in S

ize-

AST

M

D42

2-63

(07)

VOC

s - 8

265

Fe /

Mn

Test

Kit

NA

PL D

ye K

it

PID

pH

Con

duct

ivity

Tem

pera

ture

DO

OR

P

Turb

idity



Groundwater Plume Delineation

Direct Push Boring Groundwater Samples, collected during the direct push soil sampling

Variable



Triad approach; for planning

purposes, assume approximately 30

locations

Grid node ID-sample depth (or screen mid-point)-date

(DDMMYY)

Example: At location A4 for a sample collected from screen interval 10-13' on 10/9/11 the sample ID is

A4-11.5-100911

Water Grab SP16 with inertial foot valve Once

Just below the water table.

Additional deeper samples will be

collected for vertical delineation.

Low to Medium T 0 0 T T T 4 0 0 T 4 0 0 0 0 0 T N N N N N N N N N

Groundwater samples will be collected from each direct push sampling location to confirm current concentrations and delineate the current extent of contamination. Samples will be immediately analyzed by the field lab for VOCs. In each location, a sample will be collected from 2 to 5 ft below the water table. Near the source area and where needed to define the vertical extent, a sample also will be collected from 12 to 15 ft below the water table. Additional deeper samples will be collected at 5-ft intervals, if necessary, to define the vertical extent of contamination. Sampling locations will be stepped outward until evidence of contamination is not detected (benzene concentrations less than or equal to 1 ug/L based on field laboratory results). Confirmation samples will be submitted to the offsite lab to confirm the outer boundaries of the solute plumes to action levels (horizontal and vertical). Samples for offsite laboratory analysis (all COCs) will also be collected from selected locations within the plume to support permanent monitoring well placement and to delineate the extent of each of the COCs (see Worksheet #14). However, groundwater samples will not be collected from areas with NAPL.

T 0 0 T T T 4 0 0 T 4 0 0 0 0 0 TField QC Samples



Blind Sample - To be assigned a fictitious ID Water SP16 with inertial foot

valve 10% rounded upSame as the

sample it duplicates

Low to Medium T 0 0 T T T 4 0 0 T 0 0 0 0 0 T NA NA NA NA NA NA NA NA NA Field QC - indicative of precision Same as for sample duplicated

Trip Blanks for water samples NA NA 1TB-01 through 1TB-02 Water Laboratory-prepared One per cooler NA Low T 0 0 T 0 0 0 0 0 0 0 0 0 0 0 NA NA NA NA NA NA NA NA NA Field QC - indicative of accuracy

Equipment Blanks NA NA 1EB-01 through 1EB-04 Water Grab One per day NA Low T 0 0 T T T 0 0 T 0 0 0 0 0 0 NA NA NA NA NA NA NA NA NA Field QC - indicative of accuracy


associated with it Water SP16 with inertial foot valve 5% rounded up

Same as the sample with which

it is associated Low T 0 0 T T T 4 0 0 T 4 0 0 0 0 0 T NA NA NA NA NA NA NA NA NA Laboratory QC - indicative of precision

Same as primary sample, only extra volume collected.Same as for

associated sample

T 0 0 T T T 4 0 0 T 4 0 0 0 0 0 TTransformer Area Soil Sampling

0 - 2 ft Low to High 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 N N N N N N N N N

SOP-001SOP-002SOP-004SOP-005SOP-025SOP-047

2 ft - Water table Low 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 N N N N N N N N N0 0 0 0 0 0 0 8 0 0 0 0 0 0 0

Field QC Samples

Field Duplicates (10 percent rounded up)

0 ft - Water Table


Blind Sample - To be assigned a fictitious

sample ID Soil Direct Push Sampler 10% rounded up


Low to High 0 0 0 0 0 0 0 1 0 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA Field QC - indicative of precision Same as for sample duplicated

Equipment Blanks (assume 2 days of sampling by direct push)

NA NA

EBSS-03 through EBSS-04

(equipment blank for soil samples)

Water Grab One per day NA Low 0 0 0 0 0 0 0 2 0 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA Field QC - indicative of accuracySOP-001SOP-002SOP-004


associated with it Soil Direct Push Sampler 5% rounded upSame as the




0 0 0 0 0 0 0 12 0 0 0 0 0 0

Total Samples for Groundwater Plume Delineation

Groundwater Plume Delineation - Environmental Samples

SOP-001SOP-002SOP-004QC

SOP-001SOP-002SOP-004SOP-005 SOP-036 SOP-043 SOP-047

QC

Total Samples for Transformer Area Soil Sampling

0 ft - Water table


samples to be determined based on records search;

assume approximately 4

locations

Transformer Area Soil Sampling - Environmental Samples

Direct Push Boring Soil Samples

Location ID-sample depth-date (DDMMYY)

Example: At transformer location #2 for a sample

collected from 1' on 7/10/11 the sample ID is

PCB2-01-071011

Soil Grab Direct Push Sampler Once

Base records will be searched to identify the locations of any transformer sites at ST48. Soil samples will be collected from any locations identified (estimated at 4). Two samples will be collected per borehole to evaluate the possible presence of PCBs due to leaks/spills. One surface soil sample (0 to 2 ft) and one subsurface soil sample (2 ft to the water table) will be collected. The subsurface soil sample will typically be collected approximately midway between 2 ft bgs and the water table.

Page 2 of 3







Matrix Sample Type



Frequency



Level

VOC

s - 8

260B

1

VOC

s - T

O-1

5 1

VOC

s - T

O-1

5 SI

M 1

GR

O/ D

RO

/ RR

O 2

(AK

101

,102

,103

)

EDB

- 80

11

PAH

s 82

70C

SIM

Pest

icid

es 8

081A

PCB

s - 8

082

TAL

Met

als

60

20/ 7

471A

Bul

k D

ensi

ty

AST

M D

7263

-09

Poro

sity

- AST

M

D68

36-0

2(08

)

TOC

- 90

60

Moi

st. C

onte

nt

AST

M D

7263

-09

Gra

in S

ize-

AST

M

D42

2-63

(07)

VOC

s - 8

265

Fe /

Mn

Test

Kit

NA

PL D

ye K

it

PID

pH

Con

duct

ivity

Tem

pera

ture

DO

OR

P

Turb

idity



Install and sample up to 5 new shallow wells Variable Based on

monitoring well IDSample ID will be based on

monitoring well ID WaterLow flow peristaltic

pump with inertial foot valve


screened zoneLow to Medium 5 0 0 5 5 5 0 0 5 0 0 0 0 0 0 Y N N Y Y Y Y Y Y

New shallow wells will be used to supplement existing wells and to delineate the horizontal extent of the groundwater plume and establish concentrations trends. Wells will be installed with a 10 ft screen intersecting the water table. The number of samples listed is per event.

Install and sample 1 new vertical extent well Variable Based on

monitoring well IDSample ID will be based on

monitoring well ID Water Low flow pump Middle of the submerged

screened zoneLow 1 0 0 1 1 1 0 0 1 0 0 0 0 0 0 Y N N Y Y Y Y Y Y

The well will be used to delineate the vertical extent and document trends. The well depth will be determined based on the results of the vertical plume delineation sampling.

Sample 4 existing shallow wells

See Table 11-2

48MW04, 48M05, 48M06, 48MW07

48MW04, 48M05, 48M06, 48MW07 Water Low flow pump


screened zoneLow 4 0 0 4 4 4 0 0 4 0 0 0 0 0 0 Y N N Y Y Y Y Y Y The wells will be used to delineate the horizontal extent of the

groundwater plume and establish concentrations trends.

10 0 0 10 10 10 0 0 10 0 0 0 0 0

Field QC Samples



Blind Sample - To be assigned a fictitious well ID Water QC Low flow pump 10% rounded up


Low to Medium 1 0 0 1 1 1 0 0 1 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA Field QC - indicative of precision Same as for sample duplicated

Trip Blanks for water samples (assume 3 days of field sampling, 2 coolers per day)

NA NA 2TB-01 through 2TB-3 Water Laboratory-prepared One per cooler NA Low 6 0 0 6 0 0 0 0 0 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA Field QC - indicative of accuracy

Equipment Blanks 3 NA NA 2EB-01 through 2EB-03 Water Grab One per day NA Low 0 0 0 0 0 0 0 0 0 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA Field QC - indicative of accuracy (use of disposable equipment planned)

MS/MSDs (5 percent rounded up) NA Various Same as the monitoring

well associated with it Water Low flow pump 5% rounded upSame as the




18 0 0 18 12 12 0 0 12 0 0 0 0 0

Air Sampling

0

0

T T T 0 0 0 0 0 0 0 0 0 0 0

Field QC Samples

Duplicate (10 percent rounded up)

Same as being duplicated

Same as sample it duplicates

Blind Sample - To be assigned a fictitious ID Air Cumulative

Summa Canister, apply vacuum 3.8

ml/min over 24 hoursOnce

3-5 ft above floor level (breathing

zone)Low 0 T T 0 0 0 0 0 0 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA Field QC - indicative of precision Same as for sample

duplicated

Outdoor Samples (assume 1 per building/per day sampled)

3-5 ft above ground level (breathing

zone)

AirOut-(Bldg #) -(Sample #)

AirOut-Bldg #-Sample #-DDMMYY Air Cumulative


ml/min over 24 hoursOnce

3-5ft above ground level (breathing

zone)Low 0 T T 0 0 0 0 0 0 0 0 0 0 0 NA NA NA NA NA NA NA NA NA NA

One upwind air sample will be collected on every day that indoor air sampling is performed; these samples will be used to determine if any impact to indoor air may be due to sources located outdoors, rather than as a consequence of vapor intrusion.

SOP-001 SOP-002 SOP-004 SOP-005 SOP-006

T T T 0 0 0 0 0 0 0 0 0 0 0

Notes:bgs = below ground surface NA = not applicable ug/L = micrograms per literCOC = contaminant of concern NAPL = non-aqueous phase liquid VOC = volatile organic compoundDO = dissolved oxygen ORP = oxidation-reduction potentialEDB = ethylene dibromide PAH = polycyclic aromatic hydrocarbon 1 = VOC methods: for soil/groundwater use 8260B; for sub-slab/soil gas samples use TO-15; for indoor (and outdoor) air use both TO-15 and TO-15SIM.EV = extra volume PCB = polychlorinated biphenyl 2 = Exception will be made for sample locations that contain floating product.Fe = Iron PID = photoionization detector 3 = Dedicated sampling equipment will be used.ft = foot/feet QC = quality control 4 = Groundwater plume delineation will use filtered samples for metals and PAH analyses due to turbidity issues.ID = Identification SOP = standard operating procedureM. Content = moisture content T = Quantity to be determined by Triad approach.Mn = manganese TAL = target analyte list MS/MSD = matrix spike/matrix spike duplicate TOC = total organic carbon

Indoor Samples

3-5 ft above floor level (breathing

zone)

Air Cumulative Once3-5 ft above floor level (breathing

zone)Low

1.5 Low

Total Samples for Groundwater Post Plume Delineation

Groundwater Sampling Post Plume Delineation

SOP-001SOP-002SOP-004SOP-005 SOP-010 SOP-013 SOP-019 SOP-036 SOP-043 SOP-048

NA

NA NA NA NA NA

SOP-001SOP-002SOP-004

OnceGrab

Total Air Samples

Total Environmental Air Samples

00

SOP-001 SOP-002 SOP-004 SOP-005 SOP-006

0 0

0 0

0 0

NA

NA NA

NA NA NANA NA NA NA NA

0

0

0

0T T

T 01.5Sub-slab Samples Air CumulativeAirSS-(Bldg #) -(Sample #)

AirSS-Bldg #-Sample #-DDMMYY

AirIn-(Bldg #) -(Sample #)

AirIn-Bldg #-Sample #-DDMMYY


ml/min over 24 hours

Once

QC

NA0

Groundwater Post Plume Delineation - Environmental Samples

0 0 0 NAThe need for air sampling will be evaluated following the direct push soil and groundwater sampling. If needed, air sampling will be performed in accordance with ADEC vapor intrusion guidelines.

0

0 0 0 0 0

NA

Page 3 of 3


Table 11-2: EXISTING WELL CONSTRUCTION INFORMATION SOURCE AREA ST48

EIELSON AIR FORCE BASE

Well ID Date Installed

Diameter (inches)

Depth to Water* (feet)

Total Depth (feet)

Screened Interval

(feet) Slot Source

48M04 15-Aug-88 2 17.06 23 12.5-22.5 -- EA Well Inventory 2010 48M05 5-Sep-88 2 16.39 48 37.5-47.5 -- EA Well Inventory 2010 48M06 13-Sep-88 2 17.65 99.5 89-99 -- EA Well Inventory 2010 48M07 6-Oct-88 2 18.5 16 6-16 -- EA Well Inventory 2010

* Depth to Water measurements are from historical data and are questionable. Water level measurements will be obtained during the field program.

QAPP Worksheet #12 Title: Site Specific QAPP for Source Area ST48 Measurement Performance Criteria Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 12-1

QAPP WORKSHEET #12 MEASUREMENT PERFORMANCE CRITERIA TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #12 Title: Site Specific QAPP for Source Area ST48 Measurement Performance Criteria Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 12-2


QAPP Worksheet #13 Title: Site Specific QAPP for Source Area ST48 Secondary Data Criteria and Limitations Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 13-1

QAPP WORKSHEET #13 SECONDARY DATA CRITERIA AND LIMITATIONS TABLE

Secondary Data

Data Source (Originating Organization, Report

Title, and Date)

Data Generator(s) (Originating Organization,

Data Types, Data Generation/Collection

Dates) Limitations on

Data Use How Data Will Be Used 2008 ROD Review EA. Final Five-Year Review ROD Report.

September 2008. EA. General Site Information. Report Generated: September 2008.

None General information regarding the project areas; data will assist in developing project background. Historical groundwater information; data will assist in developing the sampling approach.

2002 RPO Earth Tech, Inc. Document. Remedial Process Optimization, Draft Final RPO Phase II Technical Report. December 2002.

Earth Tech, Inc. Soil gas and soil sampling data and locations. Collected: 2001/2002.

None Provides soil gas survey and soil sampling results for field work conducted in 2001/2002. Data will assist in developing the sampling approach.

1992 OU1B Interim ROD

Eielson AFB Document. Record of Decision for the United States Air Force Eielson Air Force Base, Alaska. September 1992.

Eielson AFB. Product Thickness Data. Collected: 1988-1991.

None Provides product thickness information from 1988-1991. Data will assist in developing the sampling approach.

1993 Remedial Design

Armstrong Laboratory, Brooks Air Force Base. Draft Final Remedial Design, OU1B Source Area ST-48, Eielson AFB, Alaska. September 1993.

Armstrong Laboratory, Brooks Air Force Base. Product Thickness Data. Collected: 1989-1993.


1994 ROD Eielson AFB Document. Eielson Air Force Base Operable Unit 1 Declaration of the Record of Decision. September 1994.

Eielson AFB. Product Thickness Data. Collected: 1993.

None Provides product thickness information from 1993. Data will assist in developing the sampling approach.

QAPP Worksheet #13 Title: Site Specific QAPP for Source Area ST48 Secondary Data Criteria and Limitations Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 13-2

Secondary Data

Data Source (Originating Organization, Report

Title, and Date)

Data Generator(s) (Originating Organization,

Data Types, Data Generation/Collection

Dates) Limitations on

Data Use How Data Will Be Used 1998 Sitewide Monitoring Program Report

EA. Final 1998 Sitewide Monitoring Program Report. April 1999.

EA. Product Thickness Data. Collected: 1995-1998.


Installation Restoration Program RI/FS Stage 3

Harding Lawson Associates. Installation Restoration Program Remedial Investigation/Feasibility Study Stage 3. April 1989.

Harding Lawson Associates. Soil Gas, Soil, Groundwater, and Free Product Data. Collected 1988.

Data was not validated.

Provides information on the contamination prior to remediation.

Installation Restoration Program RI/FS Stage 4

Harding Lawson Associates.. Installation Restoration Program Remedial Investigation/Feasibility Study Stage 4. May 1990.

Harding Lawson Associates. Groundwater Data. Collected: 1989.

Data was not validated.

Provides information on the contamination prior to remediation.

Well Inventory Spreadsheet

EA, Well Inventory Spreadsheet. Continuously updated.

EA. Excel spreadsheet containing historic well information collected over time.

Data are useful; however, the source cannot be verified or located for all data.

Historic groundwater monitoring well construction information.

QAPP Worksheet #14 Title: Site Specific QAPP for Source Area ST48 Summary of Project Tasks Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 14-1

QAPP WORKSHEET #14 SUMMARY OF PROJECT TASKS The project tasks identified in this worksheet provide details for the data collection activities to be performed in support of updating the CSM for Source Area ST48. In addition to listing the technical approach and specific tasks required for investigational activities at ST48, this worksheet identifies and explains the logic behind where sampling will begin, how it will progress, and when it can conclude. Samples will be collected to evaluate the current extent of soil and groundwater contamination at ST48. Sub-slab soil gas and air sampling will also be performed, if needed. The first step will be baseline groundwater sampling from existing site monitoring wells. Additionally, base records will be searched to identify the location of transformer sites at ST48, if possible. Following the baseline sampling, direct push soil and groundwater samples will be collected from areas of known impacts to document the current contaminant concentrations. Additional direct push samples will be collected to evaluate the extent of contamination by stepping out from the source areas, and collecting samples until delineation criteria have been met. The soil and groundwater delineation work will be completed using direct push (e.g., Geoprobe™) techniques in concert. Each direct push location, in increasing depth and in order of sample progression, will render:

• Shallow soil samples (0 to 2-ft depth);

• Subsurface soil samples for migration to groundwater pathways;

• NAPL screening using field test kit in the capillary fringe/smear zone within and proximal to the former NAPL plume;

• Collection of aquifer soil matrix samples for total organic carbon (TOC) and physical

properties in non-impacted areas to evaluate solute transport and retardation;

• Collection of groundwater samples at each location from just below the water table using direct push techniques to delineate the horizontal extent of contamination (based on real-time data from the field laboratory); and

• Collection of groundwater samples from deeper intervals as necessary to delineate the

vertical extent of contamination (based on real-time data from the field laboratory). After evaluation of the direct push analytical data, locations for additional permanent monitoring wells will be agreed upon by stakeholders. Additional monitoring wells will be installed including shallow wells for source area monitoring and horizontal plume delineation, and deeper wells for


Page 14-2

vertical delineation. A regimen for long-term monitoring (LTM) will be established to allow evaluation of trends, plume stability, and protectiveness of remedy to support subsequent five year reviews. LTM will be addressed under a separate Installation-Wide Monitoring Program. Air sampling (indoor, outdoor, and/or sub-slab soil gas) will be performed in, around, and beneath occupied buildings present within the contaminant plume area, if necessary, in accordance with ADEC’s Draft Vapor Intrusion Guidance for Contaminated Sites (ADEC 2009b). Results for indoor air and sub-slab soil gas samples, if collected, will be compared to allowable concentrations (see Tables 15-3a and 15-3b, respectively) to establish if the pathway is complete. There are several areas where data gaps and/or lack of repeatable groundwater data have been identified, and it is in these areas that the intrusive investigations will focus, as follows:

• Residual soil impacts post-remediation were confirmed at SB205 and SB207 (Figure 10-3). These sample locations are proximal to grid locations K-5 to L-6 shown on Figure 11-1. Sampling will begin in this general area.

• The southeast flank of the solute plume (e.g., grid locations K-9 to G-8, from south to north, Figure 11-1) lacks repeatable data. This area will be assessed for current groundwater contaminants and an adequate permanent groundwater monitoring network will be established for LTM.

• A “hot-spot” in the vicinity of 48M08 and 48M08B (area of H-2 to I-3; Figure 11-1) will be

assessed and delineated cross-gradient to the west and downgradient to the north.

• Residual NAPL impacts will be evaluated starting from two principal areas: starting at K-6 (Figure 11-1) in the area that has been remediated and between D-5 and D-6, at the leading edge of the former NAPL plume;

• The downgradient limit of solute impacts (near A-4, Figure 11-1) will be established as

well as an adequate groundwater monitoring network to support LTM.

• The RI/FS Management Plan (USAF 1993a) identified the need for determining the locations of any transformer sites in the vicinity of the Power Plant and indicated that the identified areas should be sampled for PCBs. This investigation was never carried out; therefore, soil samples will be collected from any transformer sites identified and analyzed for PCBs.

Task Sequence Following is the sequence of tasks to be performed. Details of the tasks are provided in the following sections.


Page 14-3

1. Well Survey and Baseline Groundwater Monitoring a. Survey existing wells b. Gauge existing wells c. Sample wells using low flow techniques d. Field testing of groundwater samples

2. Soil and Groundwater Plume Delineation

a. Search base records for locations of transformer sites b. Obtain Subsurface/Utility Clearance c. Determine sampling locations d. Direct push soil sampling e. Field testing and screening for soil samples f. Direct push groundwater sampling g. Geoprobe borehole abandonment h. Global Positioning System (GPS) measurements

3. Indoor Air Pathway (Vapor Intrusion)

a. Evaluate the need for air and sub-slab soil gas sampling b. Sub-slab soil gas point installation c. Indoor air and outdoor air sampling

4. Monitoring Well Installation and Sampling a. Select permanent monitoring well locations b. Drill and install wells c. Develop wells d. Sample wells using low flow techniques e. Survey Wells

5. Decontamination Procedures 6. Investigation-Derived Waste (IDW) Management

Technical Approach to Project Tasks The technical approach to be used for each task and its logic is detailed below. Areas for sampling are depicted in Figure 11-1. The grid system identified on Figure 11-1 was prepared so that stakeholders could reference certain areas of the plume and more clearly discuss the sample locations and horizontal extent of contamination in each matrix as the investigation activities are ongoing. Additional sampling details are provided in Table 11-1. Sample bottles, preservatives, and holding times are provided in Worksheet #19.


Page 14-4

1. Well Survey and Baseline Groundwater Monitoring: Baseline groundwater monitoring will be performed using existing monitoring wells at the site, as follows. a. Survey Existing Wells The four existing monitoring wells at ST48 will be surveyed to create a common datum. The four wells include 48MW04, 48MW05, 48MW06, and 48MW07. Well construction information for the existing wells is provided in Table 11-2. b. Gauge Existing Wells

Water levels in the wells will be gauged using a water level indicator or oil/water interface probe. The gauging results will be used in the creation of hydrographs and potentiometric surface maps. c. Sample Wells Using Low Flow Techniques The four existing wells will be purged and sampled using low-flow sampling protocols in accordance with ADEC’s Draft Field Sampling Guidance (ADEC 2010) and EA SOP No. 048 (Installation-Wide Generic QAPP, Appendix A). An initial water level measurement will be collected upon opening each of the wells. The pump intake will be positioned near the middle of the submerged screened interval. Groundwater will be purged at a maximum flow rate of 0.5 liters per minute because low-flow sampling requires that minimal drawdown is maintained throughout purging of the well to ensure that the water being purged is in fact entering the pump from the formation, and not as a result of lowering water levels within the well. Water level measurements will be collected periodically during purging of the well to confirm that only the permitted drawdown of 0.3 ft has not occurred. If excessive drawdown is occurring, the purge flow-rate can be slowed to minimize drawdown. Additionally, field water quality parameters will be measured and documented at regular intervals using a closed flow-through cell water quality meter. In accordance with the ADEC Draft Field Sampling Guidance, purging will continue until water quality parameters are considered stable for three successive readings, collected 3 to 5 minutes apart. ADEC considers stable to be:

• ± 3% for temperature (minimum of ± 0.2 degrees Celsius [°C]) • ± 0.1 for pH • ± 3% for conductivity • ± 10 millivolts for redox potential • ± 10% for turbidity


Page 14-5

Measurement of field parameters is further described in EA SOP No. 043 (Installation-Wide Generic QAPP, Appendix A). If a well is low yield and purged dry, a sample will not be collected until the groundwater has recharged to approximately 80% of its pre-purge volume, when practical. Otherwise, once these parameters are met, the required groundwater samples will be collected. Groundwater samples will be analyzed by an offsite laboratory for the parameters listed in Table 11-1. Over the course of the groundwater sampling event, the following will be recorded on groundwater sampling forms (included in the Installation-Wide Generic QAPP, Appendix B): the volume of water removed from the well; the depth of the pump intake; the depth-to-water measurements prior to, during, and at the completion of purging and sampling; and the identification of samples collected. d. Field Testing of Groundwater Samples Manganese and Ferrous Iron Test Kits—A Hach™ AcuVac or similar test kit will be used to test groundwater samples in the field for manganese and ferrous iron. When using Hach test kits, the sample water is placed into the provided test tube, the reagent mixed in, and the sample allowed to sit for approximately two minutes. The now colored test tube will be placed into the color wheel to compare with a separate sample, without the reagent, to determine the level of manganese and ferrous iron in the sample. See the specific Hach or AcuVac instruction manual for more information.

2. Soil and Groundwater Plume Delineation: Direct push sampling will be used to obtain a better understanding of the nature and extent of the contamination as well as the site characteristics, including soil types and physical properties. Direct push drilling refers to the tools and/or sensors that are "pushed" into the ground to remove soil or to advance a downhole instrument. A direct push machine relies on a relatively small amount of static (vehicle) weight combined with percussion as the energy for advancement of a tool string. Direct push borings will allow for mapping of the site stratigraphy, characterization of residual NAPL, delineation of the soil and groundwater contaminant plumes, and development of geologic cross sections. a. Obtain Subsurface/Utility Clearance Base Civil Engineering Work Clearance Requests (Air Force Form 103, i.e., “Dig Permits”) will be completed prior to commencing any subsurface activities at the site. Locations will be adjusted, as necessary, based on the presence of underground or overhead utilities.


Page 14-6

b. Determine Sampling Locations Direct push sampling locations will be selected based on the historical soil and groundwater data and the results of the baseline groundwater monitoring. Additional direct push sampling locations may be sampled in transformer areas, if identified, for soil sampling only. The approximate extent of the benzene plume in groundwater and the historical limits of the NAPL plume at the site are shown on Figure 11-1. Direct push sampling will begin as follows:

1. Begin sampling in the vicinity of grid cell J-5 (see Figure 11-1) within the former source area. Collect both soil and groundwater samples for analysis from each direct push boring location. Submit groundwater samples to the field laboratory for VOC analysis for screening level data. Submit selected groundwater samples to the offsite laboratory for definitive level data, as described in (e) of this task. Confirmation samples to be submitted to the offsite laboratory include samples used to confirm the outer boundaries of the solute plumes, both horizontal and vertical. Additional definitive data for groundwater samples will be obtained during sampling of permanent monitoring wells to be installed at the site. Collect soil samples and submit to the offsite laboratory, as described in (c) of this task. Conduct NAPL field screening tests to identify the presence or absence of free product and define the current extent of NAPL, as described in (d) of this task.

2. Collect groundwater samples from selected locations (at least three) within the source

area(s) for offsite laboratory analysis of the constituents identified in Table 11-1. However, groundwater samples will not be collected for offsite laboratory analysis from areas with NAPL.

3. Benzene concentrations in groundwater, based on field analyses, will be used as an

indicator of the plume extent. If results from the field laboratory indicate that benzene in the groundwater is greater than 1 µg/L, then step out approximately 50 ft to the south. Perform direct push drilling and collect samples (soil and groundwater) approximately every 50 ft until the benzene concentration in groundwater is less than or equal to 1 µg/L. Alternatively, step out at greater intervals until benzene in groundwater is less than 1 µg/L, then step back to refine the plume extent. Conduct the same process in the east and west directions from the initial sample location. When the perimeter of the plume appears to be identified based on field screening (first sample with benzene less than or equal to 1 µg/L), submit a groundwater sample from that location to the offsite laboratory for confirmation, as described in (e) of this task. Similarly, submit groundwater samples to the offsite laboratory to confirm the vertical extent of contamination as described in (e) of this task. Additional groundwater samples collected from selected locations between the source area(s) and the perimeter of the benzene plume will be submitted for laboratory analysis, as described in (e) of this task.


Page 14-7

4. To delineate the northern edge of the plume, move approximately 100 ft to the north of the initial sample location and collect samples. Submit groundwater samples to the field laboratory and soil samples to the offsite laboratory. Continue this process, collecting samples, until the benzene concentration in the groundwater is less than or equal to 1 µg/L. Samples will be submitted to the offsite laboratory as described in step 3, above, and (e) of this task.

5. When the northern boundary is determined, sample transverse lines, generally to the

east and west from the sampling locations used to delineate the northern boundary. Sample approximately every 100 ft. Samples will be submitted to the offsite laboratory as described in step 3, above, and (e) of this task.

6. Additional soil samples will be collected from locations of transformers, if identified. A

surface and a subsurface soil sample will be collected from one direct push boring at each transformer location. These samples will be submitted for laboratory analysis of PCBs only.

c. Direct Push Soil Sampling Using direct push drilling methods, collect continuous soil cores to the depth of groundwater (anticipated to be approximately 9 ft bgs) or a maximum depth of 15 ft bgs, using the 4-ft long continuous sampler with Lexan™ liner. When opening the direct push sampler and liner, screen soil for VOCs using a photoionization detector (PID), as described in task 2.d. Collect soil samples from two depths at each boring location: surface and sub-surface. The surface soil samples will be collected between 0 and 2 ft bgs. The subsurface soil sample will be collected between 2 ft bgs and the water table, from the soil interval that exhibits the highest PID measurement. Soil samples will be submitted to an offsite laboratory for analysis of the constituents listed in Table 11-1 to determine current contaminant concentrations. Additionally a sample will be collected from the capillary fringe for testing using a NAPL field dye test, as described below. During the completion of direct push soil borings, document the lithology in the log book or designated field form. Describe soil physical properties in accordance with American Society for Testing and Materials (ASTM) D2488-00 along with the Munsell soil color chart. Collect and preserve VOC soil samples as follows:

• Collect a minimum of 25 grams of soil with minimum disturbance directly into a tared 4 ounces or larger jar with a Teflon®-lined septum fused to the lid. Interim storage/containers (e.g., re-sealable polyethylene bags) are not allowed.


Page 14-8

• Immediately after collection, add a 25-milliliter (mL) aliquot of methanol until the sample is completely submerged. Complete this step as quickly as possible, within approximately 10 seconds of placing the soil in the sample jar. If an extended time period between soil collection and preservation is necessary due to site conditions or safety concerns, this will be recorded in the field notes and documented in the final report.

• Do not place tape, including evidence tape, on the sample container directly.

• Cool and retain samples in their containers at <6°C by keeping them on ice in a cooler

when onsite until they can be transferred to a refrigerator or to the lab.

• Collect another sample of the same material from the same location in an unpreserved jar for percent moisture determination.

• Discard any remaining soil from the boring into the 55-gallon drums being used for

collection of cuttings. Handle the cuttings in accordance with the IDW procedures described later in this task.

• Decontaminate sampling implements in accordance with procedures described later in

task 5.

Soil Samples for Physical Property Analysis—In addition to the samples collected for plume delineation, collect five soil samples for analysis of physical properties including bulk density by ASTM D7263-09; effective porosity by ASTM D6836-02(08), Method D; moisture content by ASTM D7263-09; total organic carbon (TOC) by Method 9060; and grain size analysis by ASTM D422-63(07). Collect these samples from representative soils, below the water table. Soil samples for physical property analysis will be selected from uncontaminated areas, outside of the plume boundaries at each compound. In general, these five sample locations will be distributed outside the perimeter of the plume, allowing evaluation of varying soil types, if present. These samples will be submitted to an offsite laboratory for analysis. d. Field Testing and Screening for Soil Samples NAPL Dye Test—Evaluate the potential presence of NAPL in the capillary fringe zone of each direct push sample location with a field dye test kit (OilScreenSoil™ or similar). Fill a test kit supplied bottle with soil and shack with the cap on. The underside of the cap has a water soluble cube that will stain any petroleum hydrocarbons present in the sample a bright blue color. To dissolve in the groundwater, the sample must be 20°C or more; therefore warm samples through activities such as by briefly and partially submerging the sample bottle in a container of warm water. Conduct the field test as instructed in the Field Screening Test Instruction Manual (Cherion Resources Ltd. 2008).


Page 14-9

PID Screening—Use a PID to detect organic vapors, and to select soil intervals for sampling. Collect a sample of the soil with the highest PID readings between 2 ft and the water table for analysis. No headspace samples are being collected. Perform PID screening directly from soil cores to allow rapid sample collection and minimize the loss of VOCs, using the following procedure:

• Immediately after the soil core is removed from the drill rod, cut the Lexan liner along the length of the core.

• Immediately place the PID probe above the freshly exposed soil, being careful not to touch the sample.

• Collect a sample from the area exhibiting the highest PID reading.

• Document field screening results in the field record or log book. Calibrate the PID field instruments each day according to the manufacturer’s specifications and requirements, and EA SOP No. 011 (Installation-Wide Generic QAPP, Appendix A). e. Direct Push Groundwater Sampling Collect groundwater samples from each direct push sampling location. The subcontracted driller will collect the groundwater samples during direct push sampling by advancing an SP-16 sampler or similar. The device consists of a stainless steel screen within the drive tip rod. The SP-16 sampler and drill string is driven to the desired sample depth and the screen is held down using a trip rod while the drill string is retracted, thus exposing the screen section (typically about 3 ft long) for acquiring aqueous samples. Disposable polyethylene tubing with an inertial foot valve installed on the bottom is used to oscillate the water from depth to the surface for sample collection. Field screening for the groundwater samples will include VOC Method 8265 analysis performed by a subcontractor, Triad, who will be running the field laboratory. Triad’s SOP for VOC sampling is provided in the Installation-Wide Generic QAPP, Appendix H. Method 8265 is described in the Installation-Wide Generic QAPP, Appendix I. At each location, collect one sample from 2 to 5 ft below the water table and immediately deliver the sample to the field laboratory for VOC analysis under chain-of-custody protocols. If evidence of contamination is observed or if, based on real time data, benzene in that groundwater sample exceeds 1 µg/L, then collect a second sample from 12 to 15 ft below the water table. If results from the field laboratory indicate the deeper sample exceeds 1 µg/L benzene, collect a sample at the 17 to 20 ft interval below the water table and at subsequent depths (in 5-ft intervals) until vertical delineation is established. This may require leaving rods and the sampler in place, and temporarily moving to another location to sample, while waiting for the field laboratory results. At subsequent locations, continue sampling at depth intervals


Page 14-10

required for vertical delineation until data from the field laboratory indicate that the extent of benzene has been defined. Continue stepping out, as described in section 2.b, until the horizontal and vertical extent of benzene contamination has been delineated based on field analyses. If evidence of contamination is observed (odor or staining) beyond the apparent limits of benzene impacts based on the field laboratory data, continue stepping out until apparent contamination is no longer observed. Once VOC results from the field laboratory indicate that the horizontal or vertical extent of benzene contamination in groundwater has been defined (below 1 µg/L), then collect samples for submittal to the offsite laboratory for analysis of the constituents indicated in Table 11-1. To define the vertical extent of contamination, a sufficient number of samples will be submitted to the offsite laboratory for analysis, with the number dependent on site conditions but not less than two samples. To define the horizontal extent, a shallow groundwater sample from the outermost direct push boring in each traverse sampled will be submitted to the offsite laboratory for analysis. In addition to the confirmation samples for benzene plume delineation, selected groundwater samples from within currently impacted areas will be submitted to the offsite laboratory for analysis of the constituents listed in Table 11-1 to define the extent of less mobile site contaminants. In general, these samples will be collected at approximately 100-ft intervals between the source area and the benzene plume extent. However, these locations may be adjusted based on professional judgment including consideration of real-time water quality parameters obtained during sampling, mobility of the COCs, locations of release points, and quantities of contaminants expected to have been released to groundwater. f. Geoprobe Borehole Abandonment Abandon Geoprobe boreholes according to ADEC’s Monitoring Well Guidance (ADEC 2009a). Using tremie pipe, place grout from the bottom of the hole to the ground surface. Include in the records of work boring logs, samples, completion records, and abandonment procedures. g. Global Positioning System (GPS) Measurements After performing the direct push boring and sample collection, survey the boring location (location can be marked with labeled flag and surveyed at a later time) using a handheld Trimble GPS or equivalent with sub meter accuracy. The survey points will be post-processed to bring into the existing database of Universal Transverse Mercator survey coordinates with a system reference of WGS 84 Universal Transverse Mercator meters.


Page 14-11

3. Indoor Air Pathway a. Evaluate the Need for Sub-Slab Soil Gas and Air Sampling Soil and groundwater data collected during the direct push sampling will be reviewed to determine if the air exposure pathway requires evaluation. If appropriate, the evaluation of this pathway and the decision making for sampling will be determined following the steps outlined in the ADEC Vapor Intrusion Guidance (ADEC 2009b). Sub-slab soil gas samples and indoor air samples, if warranted, will be collected to test for contaminant exposure pathways and assure protection of human health and the environment. Outdoor air samples will be collected to evaluate the ambient background air concentration if indoor air samples are collected. See Tables 15-3a and 15-3b for limits on VOC concentrations in air (indoor and sub-slab/soil gas, respectively). b. Sub-slab Soil Gas Point Installation Sub-Slab Soil Gas Sampling—Collect a minimum of three sub-slab soil gas samples per building sampled to evaluate the vapor intrusion pathway. Follow the procedures below for the selection and installation of each sub-slab soil gas point location.

• Complete a visual assessment of the condition of the floor of each building. Select the locations of the sub-slab soil gas points out of the line of traffic, away from major cracks and other floor penetrations (sumps, pipes, etc.), and a minimum of 5 ft from an exterior wall.

• Once the location is determined, drill a ⅜-in. diameter hole approximately 2 in. below the concrete floor slab using an electric hammer drill. Use a 1-in. diameter drill bit to over drill the top ½ in. of the borehole to create an annular space for the surface seal. Sweep away concrete dust and flooring material from the drill hole and wipe with a dampened towel.

• Insert Teflon™-lined polyethylene tubing (¼-in. outside diameter/⅛-in. inside diameter, and approximately 3-ft long) into the borehole drilled in the concrete floor, extending no further than 2 in. below the bottom of the floor slab.

• Pour melted beeswax around the tubing at the floor penetration and allow to set tightly

around the tubing.


Page 14-12

• Once the sub-slab soil gas points are installed and the bees wax is significantly dry, perform leak tests using helium tracer gas. Utilize a leak test bucket to infuse the area surrounding the sub-slab soil gas point with helium; once helium detector concentrations indicate approximately 100 percent helium within the leak bucket, purge the sub-slab soil gas point of approximately 2 to 3 liters (L) of air using a GilAir 5 air pump. Discharge the purge air into a Tedlar bag connected directly to the air pump. Purge the Tedlar bag first with the ppbRAE to record total VOC concentrations and then with the helium detector to assess the competency of the sub-slab seal. Record the associated readings on the field sampling form.

• Connect a 6-L Summa® canister (provided by an independent laboratory) with a vacuum

gauge and flow controller to the sample tubing using a compression fitting and place on the floor adjacent to the sampling point. The canisters will be individually certified clean in accordance with USEPA Method TO-15 and under a vacuum pressure of no less than -25 in. of mercury (Hg) or a replacement canister will be used. Regulate flow controllers to collect at 3.8 milliliters per minute (mL/min) over a 24-hour collection period.

• The serial number of the canister and associated flow regulator will be recorded on the

field sampling form. Sample identification including sample name, sample start date/time, vacuum gauge pressure, and required analysis (USEPA Method TO-15) will be recorded on the canister identification tag and the field sampling form.

• A digital photograph will be taken of the canister setup and the surrounding area.

Record pertinent sample information on the associated chain of custody and repackage into the originating box. Submit soil gas samples to Air Toxics Ltd. for VOC analysis by USEPA Method TO-15. Upon completion of the sampling, remove the temporary sub-slab soil gas sampling points and seal them with hydraulic cement. c. Indoor Air and Outdoor Air Sampling Indoor Air—Collect representative air samples from within the breathing zone (i.e., 3-5 ft above the floor) in each building evaluated, if results of sub-slab sampling indicate a potential pathway. Samples will be collected on the ground floor of the building evaluated. One sample will be collected per 1,000 square feet of floor space per building. Follow sampling and documentation instructions for air sample collection as described below. Air samples will be collected in accordance with ADEC Vapor Intrusion Guidance (2009b) and EA SOP No. 006 (Installation-Wide Generic QAPP, Appendix A). Connect a 6-L Summa® canister (provided by an independent laboratory) with a vacuum gauge and flow controller to the sample tubing using a compression fitting and place on the floor adjacent to the sampling point. The canisters will be individually certified clean and under a vacuum pressure of no less than -


Page 14-13

25 in. of Hg or a replacement canister will be used. Regulate flow controllers to collect at 3.8 mL/min over a 24-hour collection period. The serial number of the canister and associated flow regulator will be recorded on the field sampling form. Sample identification including sample number, sample start date/time, vacuum gauge pressure, and required analysis (USEPA Method TO-15) will be recorded on the canister identification tag and the field sampling form. A digital photograph will be taken of the each canister setup and the surrounding area. After the sample collection period, close the canister valves to terminate the sample collection. If the canister vacuum gauges will be recorded at -5 in. of Hg or below, before the 24-hour collection period had concluded, close the canister valves to terminate the sample collection. Due to the inherent error associated with flow regulator gauges, terminate sample collection prior to reaching -4 in. of Hg when access to the canister will be limited. Record the flow controller ending gauge pressures and sample end times on the canister identification tags and the field sampling forms. Once sample collection is terminated, remove the canisters and flow controllers from the sample tubing and place them into the shipping box. Record pertinent sample information on the associated chain-of-custody and submit with sample. All air samples will be sent to Air Toxics Ltd. for VOC analysis by USEPA Method TO-15. Outdoor Air—These samples represent outdoor ambient air and will be utilized to determine if any impact to indoor air may be due to sources located outdoors, rather than a consequence of vapor intrusion. Outdoor air samples are collected as field QC. Collect one sample on every day that indoor air sampling is performed. Outdoor ambient air samples will be collected upwind from the study area. Collect outdoor ambient air samples from within the breathing zone (i.e., 3-5 ft above the ground surface) during a sample period corresponding with indoor air sampling. If sample locations are unable to achieve the elevated sampling zone, use dedicated Teflon-lined polyethylene tubing to reach the breathing zone. Follow sampling instructions as described above. 4. Monitoring Well Installation and Sampling a. Select Permanent Monitoring Well Locations After plume delineation from direct push sampling, install permanent monitoring well locations in areas where coverage is not available by existing wells. Up to five monitoring wells with screens intersecting the water table will be installed to delineate the horizontal extent of the plume or to monitor concentrations in the source area(s). In addition, one deeper well (estimated to extend 20 ft below the water table) will be used to evaluate the vertical extent of the plume. The screen depth for this well will be selected based on the vertical extent of contamination detected during the direct push groundwater plume delineation activities. Locations will be discussed/decided on with the stakeholders, following review of results from the direct push soil and groundwater plume delineation activities.


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b. Drill and Install Wells Install permanent monitoring wells using either hollow stem auger or direct push drilling equipment in accordance with ADEC’s monitoring well guidance and EA SOP No. 019 (Installation-Wide Generic QAPP, Appendix A). During hollow stem auger drilling, a sampler is typically driven every 5 ft in depth to allow for logging of lithology, characterization of soil stratigraphy, and sample collection for physical properties. With direct push drilling a continuous soil core will be collected to the depth of the well to be installed, to allow for logging of lithology, characterization of soil stratigraphy, and sample collection for physical properties. Construct wells with a 2-in. diameter schedule 40 polyvinyl chloride (PVC) threaded casing with 10-ft of 0.010-in. slot well screen. Construct the sand pack surrounding the well screen to consist of either 10/20 or 20/40 silica sand and to extend to approximately 2 ft above the top of the screen. Seal the annulus above the sand pack with hydrated bentonite. Monitoring wells may be completed as either above ground stickups in protective shrouds or surface completions with a flush-set protective well cover. Completion will be determined in the field based on the location surroundings. Install a set of three bollards around any stick up completions. c. Develop Wells Well development should not proceed until 48 hours after well installation to allow annular seal materials to set or cure. Develop wells by using a combination of pumping and/or bailing and surging as described in EA SOP #19 (Installation-Wide Generic QAPP, Appendix A). Monitor water quality parameters such as turbidity, pH, dissolved oxygen, temperature, and specific conductance periodically during well development and record in the log book. Continue development until turbidity decreases, and target values for water quality parameters are met, as listed in SOP No. 19. d. Sample Wells Using Low Flow Techniques Collect low flow samples as directed above in Task 1.c. Parameters for sampling are listed in Table 11-1. Sample new wells for VOC by 8260, EDB by 504.1, lead. Field test kits will be used for analysis of ferrous iron and manganese, as described in Task 1.d. After installation of the new wells, begin a sampling schedule of two sampling events per year for two years for site monitoring wells, or as determined in a subsequent LTM plan. The groundwater samples collected during these events will be used to further characterize the groundwater quality and plume characteristics of Source Area ST48 and to monitor the long term trends. Consistent sampling across delineated plume areas will generate reproducible long term data and provide justification for future site closures.


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e. Survey Wells A licensed land surveyor will survey the new wells using a GPS or Total Station to the existing datum. Horizontal locations (X,Y) will be surveyed to an accuracy ± 0.1 ft and elevations (Z) will be surveyed to an accuracy ± 0.01 ft. Horizontal and vertical measurements will be collected in the WGS 84 Universal Transverse Mercator meters coordinate system. The new well information will be incorporated into the existing gauging network to further develop hydrographs and potentiometric surface maps. Survey measurements will also be recorded in the master well list for the base. 5. Decontamination Procedures Decontaminate all field equipment (such as drilling rods, water elevation meters, and groundwater sampling equipment) prior to the initial use, between sample locations, and after final use to ensure no cross-contamination occurs. Decontamination will be performed according to EA SOP No. 005 (Installation-Wide Generic QAPP, Appendix A) and protocols will be strictly adhered to minimize cross contamination. Collect, containerize, label for disposal, and handle liquids generated during the decontamination process in accordance with the IDW management procedures described in task 5. To the degree possible, use dedicated and/or disposable sampling equipment. If non-dedicated equipment is used, collect equipment blank samples to verify that no residual contamination remains on the equipment and proper decontamination procedures have been implemented. 6. IDW Management IDW (both soil and water) will be placed in drums pending disposal and where applicable, will be characterized for disposal using analytical data generated during the field sampling program. Additional information on IDW characterization is provided under IDW Profiling. No container will be labeled as a “Hazardous Waste” unless the contents are in fact known to be hazardous as defined by 40 Code of Federal Regulations FR 261. IDW may be disposed onsite if it is: (1) initially screened, or evaluated to determine whether it is contaminated; (2) not abandoned in an environmentally unsound manner; and (3) not inherently waste-like. IDW are to be considered contaminated if they: (1) are visually or grossly contaminated, (2) have activated any field monitoring device which indicates that the level exceeds standard Level 1, (3) have previously been found to exhibit levels of contamination above environmental quality standards, and (4) the responsible party and/or appropriate regulator deem(s) that records of historical uses indicate that additional testing of the IDW is needed, or additional caution is warranted handling IDW from a given site.


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a. IDW Containerization All water, soil, and other wastes from sampling and initial development of new wells, and purge water generated during groundwater sampling will be containerized in Department of Transportation approved 55-gal drums. Decontamination fluids may be bulk-containerized until completion of field tasks. Label all containers as to type of media, the date the container was sealed, the point-of generation, and the points-of-contact. The well number and container number will be identified on the container. All wastes will be transported in accordance with appropriate waste manifesting procedures. Containerized decontamination fluids or soils may be characterized by obtaining one grab samples from the drums, by bailer for liquids, or using stainless steel sampling scoops for soil. These grab samples will be submitted to an offsite laboratory for analysis of COCs from the specific source area from which the material was generated. b. IDW Profiling Profiling for soil cuttings and purge groundwater will be based on investigation sample results. For this reason, all soil IDW from the soil source delineation borings and purge and development water will not be resampled. Because the plume delineation will require installation of borings outside of the source area, it is anticipated that the soil will not be highly contaminated. Soil cuttings from these borings will be characterized by compositing aliquots from no more than 10 drums from the same boring. The aliquots will be collected with a hand auger from the center of each drum. These aliquots are considered representative of each drum, as the soil IDW was mixed initially when it came up during drilling and then again when loaded up in drums. The collection of the aliquots from the center of the drum will ensure that for soil sampled was not exposed to the ambient air and volatilization was minimized. These aliquots will be composited into one sample which will be sent to the offsite laboratory for analysis by Alaska Methods AK102 and AK103 for DRO and RRO. For VOC and GRO analysis, one grab sample will be collected for each 10-drum group from each boring. This sample, which is considered representative for each group, will be analyzed by the analytical laboratory by USEPA method SW8260B for VOCs and Alaska Method AK101 for GRO. The cuttings from borings installed in the source area will be characterized by compositing aliquots from no more than 5 drums from the same boring. The aliquots will be collected with a hand auger from the center of each drum. These aliquots are considered representative of each drum, as the soil IDW was mixed initially it came up during drilling and then again when loaded up in drums. The collection of the aliquots from the center of the drum will ensure that for soil sampled was not exposed while stored to the ambient air and volatilization was minimized. These and will be sent to the offsite laboratory for analysis by Alaska Methods AK102 and AK103 for DRO, and RRO. For VOC and GRO analysis, one grab sample will be


Page 14-17

collected for each 5 drum group from each boring. These samples will be analyzed by USEPA method SW8260B for VOCs and Alaska Method AK101 for GRO. If roll off bins are used, 8 aliquots will be collected from each bin and will be composited for analysis of non-volatile type compounds. For VOC and GRO analysis, two samples will be collected, one from each end of the roll off bin. Decontamination water will be sampled by collection a composite of aliquots collected from no more 10 drums. The samples will be sent to the offsite laboratory for analysis by USEPA methods SW8260B for VOCs, SW8011 for EDB, and Alaska Methods AK101, AK102, and AK103 for GRO, DRO, and RRO. c. IDW Intended Disposal Purge water will be treated onsite using a portable carbon filter and discharged onsite near where it was collected. Decontamination water will be treated onsite using a portable carbon filter and containerized and sampled. Pending analytical results, decontamination water will either be discharged onsite or properly disposed of offsite at a permitted Treatment and Disposal (T&D) facility. Soil cuttings will be containerized in 55-gallon drums and characterized for disposal at a proper T&D facility. Analysis Tasks: Samples for laboratory analysis will be sent to the offsite laboratory, which will process, prepare, and analyze chemicals of concern in soil and groundwater. PID measurements, water quality parameters, manganese and ferrous iron field screening, field screening for VOCs in groundwater by Method 8265, and NAPL dye test screening are planned for in the field. See Table 11-1 for analytical requirements for each sample. Quality Control Tasks: Field and laboratory QC samples are listed on Worksheet #12 and on Table 11-1. Table 11-1 depicts only the laboratory QC samples that have an impact on field collection, such as the matrix spike (MS)/matrix spike duplicates (MSDs). Laboratory QC samples will be prepared and analyzed according to the analytical method requirements and the laboratory’s QA Plan. Laboratory technical systems audits will be conducted by the Contract Laboratory QA manager prior to the start of the field sampling program, as identified in Worksheet #7. The Project Chemist will review data as it is submitted to ensure that the laboratory is reporting in conformance with the QAPP and QC non-conformance issues are tracked and resolved as soon as possible.


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Secondary Data: See Worksheet # 10 for a synopsis of secondary data. Data Management Tasks: Analytical data will be ultimately placed in the ERPIMS database after verification and validation. The analytical requests will be coordinated by the Field Team Leader and the Project Chemist and chain-of-custody documentation will be filled out in the field by the sampling team. Field measurements will also be included in the ERPIMS. The final computer-aided drafting and design drawings will be prepared in Microstation 95 or higher and Geographic Information System data in Environmental Systems Research Institute (ArcView®/ArcInfo) format, and conform to the Spatial Data Standards Facility, Infrastructure, and Environment data standard. EA will ensure that the data are maintained electronically and stored in the Eielson AFB spatial database. A series of software applications will be used to handle chemical data from the time of sample collection to processing for the report. At the end of the project, the chemical data and associated location information, field sample information, and chain-of-custody information will be stored in the USAF ERPIMS database. Documentation and Records: Soil sample locations will have GPS locations surveyed and recorded; a field notebook will be used to record information about each sample, along with field measurements. Monitoring wells will have northing, easting, top-of-casing elevation, and ground elevation surveyed by a licensed surveyor as described in task 4.e. Each sample will be tracked using secure chain-of-custody protocol until receipt at the laboratory and using laboratory sample logs afterward. Air bills for overnight courier service will be retained. Site conditions, field measurements, and soil descriptions will be recorded in the field logbook. Additional field forms may be completed as required by SOPs (Installation-Wide Generic QAPP, Appendices A and B). Boring logs will be completed for each monitoring well borehole and a well completion diagram will be prepared in the field. Development times, volumes, field measurements, and notes will be recorded in the field notebook and on appropriate field forms. Well purging information will be recorded on a field form, including notes on groundwater sample collection. Well logs from all new monitoring wells will be included in the report to be submitted after field work is completed. An administrative record will be maintained in accordance with US EPA policy and guidelines. An index of documents shall be maintained in the administrative records on a quarterly basis, if changes have occurred. All documentation and records will be maintained within EA’s project files which are located at the EA office in Fairbanks, Alaska. The documents to be retained are


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indicated in Worksheet #29. All data and report records will be retained for a minimum of ten years and offered to EPA and ADEC prior to disposal per the Eielson Federal Facility Agreement. Assessment/Audit Tasks: Field sample collection and documentation audits will be conducted on site by the EA Project QA/QC Manager, as identified in Worksheet #7. Data Review Tasks: The analytical data package from the offsite laboratory will be validated by the EA Project Chemist independent of data collection and analysis activities, or a third-party, in accordance with the National Functional Guidelines for Superfund Organic Methods Data Review (USEPA 2008) and the National Functional Guidelines for Inorganic Superfund Inorganic Data Review (USEPA 2010) with respect to QA/QC parameters and as specified in the project-specific planning documents and this QAPP. Ten percent of the data packages will receive full validation. The remaining data packages will receive a less thorough validation that will meet the requirements of the DEC Laboratory Data and Quality Assurance Policy - Technical Memorandum. Packages for full validation will be selected randomly; however, full validation will be performed on packages containing results for all media. An assessment of data usability will be performed as described in Worksheet #37 using precision, accuracy, representativeness, completeness, comparability, and sensitivity parameters. Any limitations will be compared to the PQOs and evaluation criteria. Corrective actions will be made upon decision of necessity to maintain the overall quality of the project. The electronic data will be verified by comparison to the hard copy data packages. Although manual data entry will be avoided if at all possible, manual entry may be necessary for some field parameters or survey data. If manual data entry is performed, verification will be performed by a second person. The electronic data to be imported into the ERPIMS database will be verified by the third-party data validator. The final verified and validated data will be electronically uploaded and stored in the ERPIMS database using the ERPIMS guidance and tools located at http://www.afcee.af.mil/resources/restoration/erpims/index.asp.

http://www.afcee.af.mil/resources/restoration/erpims/index.asp


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QAPP Worksheet #15 Title: Site Specific QAPP for Source Area ST48 Reference List and Evaluation Tables Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 15-1

QAPP WORKSHEET #15 REFERENCE LIST AND EVALUATION TABLES Tables 15-1, 15-2, 15-3a and 15-3b present the reference list and action level criteria for soil, groundwater, indoor air, and subslab/soil gas, respectively. These tables detail the analytical groups and concentration levels for each compound for which soil, groundwater, and air samples may be analyzed during the CSM update at Source Area ST48 at Eielson AFB. For each target analyte, the screening criteria have been identified as follows.

1. For the soil samples, the screening levels will be based on the 18 Alaska Administrative Code (AAC) 75 ADEC Cleanup Levels (ADEC 2008). If these values are not available, the USEPA Regional Screening Levels (RSLs) (USEPA 2011) will be used. If the RSLs are updated, the screening levels will be updated. The screening values have been modified for direct contact and inhalation to reflect an increased risk factor for a non-cancer hazard quotient of 0.1 and a cancer risk of 1 × 10-6. Soil screening levels are shown in Table 15-1.

2. For water samples, the screening levels will be based on the ADEC Groundwater Cleanup Levels in 18 AAC 75 (ADEC 2008). Groundwater screening levels are shown in Table 15-2.

3. For indoor air and subslab/soil gas samples, the screening levels will be based on the

Draft Vapor Intrusion Guidelines for Contaminated Sites (ADEC 2009b) and the Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils (USEPA 2002). If the USEPA RSLs are updated, the screening levels will be updated. Screening levels for indoor air and subslab/soil gas are shown in Tables 15-3a and 15-3b, respectively. Outdoor air samples will be collected as quality control samples to confirm that indoor air quality is not affected by ambient air quality; therefore, results of outdoor air samples will not be compared to any standards.

Tables 15-1, 15-2, 15-3a, and 15-3b present the project action levels (PALs) for the target analytes, along with the achievable laboratory limits. Please note that matrix effects or necessary dilutions may affect the laboratory limits actually reported for project samples.

Definitions for the laboratory quantitation limits are provided in Worksheet #37 (Installation-Wide Generic QAPP). The PAL is the lowest of the available screening criteria for this source based on the CSM presented in Worksheet #10. Ideally, the practical quantitation limit (PQL) has been established at one tenth of the value of the PAL. In some cases, however, the achievable laboratory limits do not support a PQL established at one tenth of the value of the PAL. For these analytes, the limit of quantitation (LOQ) has been used as the PQL. For a small subset of the target analytes, the LOQ exceeds the PQL (shown as highlighted and in bold font in Tables

QAPP Worksheet #15 Title: Site Specific QAPP for Source Area ST48 Reference List and Evaluation Tables Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 15-2

15-1, 15-2, 15-3a, and 15-3b). The text below describes how these compounds will be evaluated in the instances in which the LOQ exceeds the PAL.

Quantitative concentration results within specified limits of precision and bias can only be achieved at or above the LOQ; however, the analytical laboratories may identify analytes between the detection limit (DL) and the LOQ. In these instances, the laboratories will report concentration values between the DL and the LOQ as estimated values. The laboratory will report nondetectable values as less than the LOD.

Compounds for which the PQL is higher than the PAL will be approached on a case-by-case basis in collaboration with stakeholders as follows:

1. The potential for the compound to be present at the site will be evaluated based on previous detections in either of the media (soil or groundwater) previously sampled at the site.

2. The potential for the compound to be present at the site will be evaluated based on previous known historical operations.

3. The potential for the compound to be present at the site due to migration from upgradient sources will be evaluated.

Table 15-4 summarizes the handling of compounds for which the LOQ, LOD, and DL are higher than the screening levels and provides an assessment by medium and by compound. It also provides an approach for the determination of data gaps because of laboratory limits that exceed screening levels. Note that while residential indoor air screening levels are not considered applicable for existing site buildings, if residential buildings are constructed at the site in the future, indoor air sampling and/or mitigation measures may be appropriate at that time.

A risk assessment is not planned for this data gap study, which will be performed to acquire data for the CSM update. However, the uncertainty associated with the use of estimated values reported below the LOQ will be discussed in the data usability section of the report.

The calculation of site-specific screening levels for migration of compounds from soil to groundwater noted in Table 15-4 will be performed according to the USEPA RSL User’s Guide (USEPA 2011).

TABLE 15-1 REFERENCE LIMITS AND PROJECT QUANTITATION LIMITS FOR SOIL, SOURCE AREA ST48, EIELSON AIR FORCE BASE, ALASKA

Screening LevelsRisk-Based

Screening Level (Direct Contact) 1

Screening Level (Outdoor

Inhalation) 2

Cleanup Levels (Migration to

Groundwater) 3LOQ LOD DL

Total Petroleum HydrocarbonsGasoline Range Organics (C6 to C10) AK101 NS mg/kg 1,400 1,400 300 300 30 4.0 1.1 0.46Diesel Range Organics (C10 to C25) AK102 NS mg/kg 10,250 12,500 250 250 25 20 6.2 2.0Residual Range Organics (C25 to C36) AK103 NS mg/kg 10,000 22,000 11,000 10,000 1,000 50 32 10Volatile Organic Compounds Acetone SW8260B 67-64-1 µg/kg nc 9,130,000 6,860,000 88,000 88,000 8,800 400 300 100Benzene SW8260B 71-43-2 µg/kg c 15,000 1,100 25 25 16 16 10 4.0Bromobenzene SW8260B 108-86-1 µg/kg nc 30,000 * NS 59 * 59 40 40 30 10Bromochloromethane SW8260B 74-97-5 µg/kg nc 16,000 * NS 21 * 21 40 40 30 12Bromodichloromethane SW8260B 75-27-4 µg/kg c 13,000 1,000 44 44 40 40 30 10Bromoform SW8260B 75-25-2 µg/kg c 110,000 42,000 340 340 40 40 30 11Bromomethane (Methyl bromide) SW8260B 74-83-9 µg/kg nc 14,000 1,400 160 160 140 140 100 352-Butanone (Methyl ethyl ketone) SW8260B 78-93-3 µg/kg nc 6,080,000 2,330,000 59,000 59,000 5,900 400 300 100n-Butylbenzene SW8260B 104-51-8 µg/kg nc 100,000 4,200 15,000 4,200 420 40 30 10sec-Butylbenzene SW8260B 135-98-8 µg/kg nc 100,000 4,100 12,000 4,100 410 40 30 10t-Butylbenzene SW8260B 98-06-6 µg/kg nc 100,000 7,000 12,000 7,000 700 40 30 10Carbon disulfide SW8260B 75-15-0 µg/kg nc 480,000 25,000 12,000 12,000 1,200 40 30 10Carbon tetrachloride SW8260B 56-23-5 µg/kg c 6,400 310 23 23 20 20 15 5.0Chlorobenzene SW8260B 108-90-7 µg/kg nc 200,000 20,000 630 630 63 40 30 10Chloroethane (Ethyl chloride) SW8260B 75-00-3 µg/kg c 290,000 2,300 580,000 2,300 400 400 300 100Chloroform SW8260B 67-66-3 µg/kg c 100,000 320 460 320 40 40 30 10Chloromethane (Methyl chloride) SW8260B 74-87-3 µg/kg c 64,000 2,500 210 210 400 400 300 1002-Chlorotoluene SW8260B 95-49-8 µg/kg nc 160,000 * NS 710* 710 71 40 30 104-Chlorotoluene SW8260B 106-43-4 µg/kg nc 160,000 * NS 710* 710 71 40 30 131,2-Dibromo-3-chloropropane (DBCP) SW8260B 96-12-8 µg/kg c 5.4 * NS 0.00014 * 0.00014 200 200 150 66Dibromochloromethane (Chlorodibromomethane) SW8260B 124-48-1 µg/kg c 9,900 1,400 32 32 40 40 30 101,2-Dibromoethane (Ethylene dibromide [EDB]) SW8260B 106-93-4 µg/kg c 420 60 0.16 0.16 40 40 30 10Dibromomethane (Methylene bromide) SW8260B 74-95-3 µg/kg nc 100,000 37,000 1,100 1,100 110 40 30 101,2-Dichlorobenzene SW8260B 95-50-1 µg/kg nc 910,000 4,500 5,100 4,500 450 40 30 101,3-Dichlorobenzene SW8260B 541-73-1 µg/kg nc 910,000 6,900 28,000 6,900 690 40 30 101,4-Dichlorobenzene SW8260B 106-46-7 µg/kg c 35,000 3,000 640 640 64 40 30 10Dichlorodifluoromethane SW8260B 75-71-8 µg/kg nc 2,030,000 38,000 140,000 38,000 3,800 40 30 101,1-Dichloroethane SW8260B 75-34-3 µg/kg c 2,030,000 90,000 25,000 25,000 2,500 40 30 101,2-Dichloroethane SW8260B 107-06-2 µg/kg c 9,100 480 16 16 40 40 30 101,1-Dichloroethene SW8260B 75-35-4 µg/kg c 1,400 85 30 30 20 20 15 5.01,2-Dichloroethene (cis) SW8260B 156-59-2 µg/kg nc 100,000 13,000 240 240 40 40 30 101,2-Dichloroethene (trans) SW8260B 156-60-5 µg/kg nc 200,000 16,000 370 370 40 40 30 101,2-Dichloropropane SW8260B 78-87-5 µg/kg c 12,000 530 18 18 12 12 10 3.91,3-Dichloropropane SW8260B 142-28-9 µg/kg nc 160,000 * NS 250 * 250 40 40 30 102,2-Dichloropropane SW8260B 594-20-7 µg/kg NS NS NS NS 40 40 30 101,1-Dichloropropene SW8260B 563-58-6 µg/kg NS NS NS NS 40 40 30 101,3-Dichloropropene (cis) SW8260B 10061-01-5 µg/kg NS NS NS NS 16 16 10 4.01,3-Dichloropropene (trans) SW8260B 10061-02-6 µg/kg NS NS NS NS 16 16 10 4.01,3-Dichloropropene (total) SW8260B 542-75-6 µg/kg c 8,300 2,700 33 33 32 32 20 8.0Ethylbenzene SW8260B 100-41-4 µg/kg c 1,010,000 11,000 6,900 6,900 690 40 30 10Hexachlorobutadiene SW8260B 87-68-3 µg/kg c 1,300 380 120 120 40 40 30 102-Hexanone SW8260B 591-78-6 µg/kg nc 21,000 * NS 11 * 11 200 200 150 50Isopropylbenzene (Cumene) SW8260B 98-82-8 µg/kg nc 1,010,000 6,200 51,000 6,200 620 40 30 10p-Isopropyltoluene SW8260B 99-87-6 µg/kg NS NS NS NS 40 40 30 104-Methyl-2-pentanone (Methyl isobutyl ketone) SW8260B 108-10-1 µg/kg nc 810,000 210,000 8,100 8,100 810 200 150 50Methylene chloride SW8260B 75-09-2 µg/kg c 110,000 16,000 16 16 40 40 30 10Methyl-tertiary-butyl ether SW8260B 1634-04-4 µg/kg c 460,000 29,000 1,300 1,300 130 40 30 10Naphthalene SW8260B 91-20-3 µg/kg nc 140,000 2,800 20,000 2,800 280 40 30 10n-Propylbenzene SW8260B 103-65-1 µg/kg nc 100,000 4,200 15,000 4,200 420 40 30 10Styrene SW8260B 100-42-5 µg/kg nc 2,030,000 20,000 960 960 96 40 30 101,1,1,2-Tetrachloroethane SW8260B 630-20-6 µg/kg c 1,900 * NS 0.20 * 0.20 40 40 30 101,1,2,2-Tetrachloroethane SW8260B 79-34-5 µg/kg c 4,200 550 17 17 10 10 8.8 3.3Tetrachloroethene (PCE) SW8260B 127-18-4 µg/kg c 1,500 1,000 24 24 16 20 15 5.0Toluene SW8260B 108-88-3 µg/kg nc 810,000 22,000 6,500 6,500 650 40 30 101,2,3-Trichlorobenzene SW8260B 87-61-6 µg/kg nc 4,900 * NS 87 * 87 40 40 30 101,2,4-Trichlorobenzene SW8260B 120-82-1 µg/kg nc 100,000 4,100 850 850 85 40 30 101,1,1-Trichloroethane SW8260B 71-55-6 µg/kg nc 2,030,000 36,000 820 820 82 40 30 101,1,2-Trichloroethane SW8260B 79-00-5 µg/kg c 15,000 1,100 18 18 12 12 8.8 3.0Trichloroethene (TCE) SW8260B 79-01-6 µg/kg c 2,100 57 20 20 16 16 10 4.0Trichlorofluoromethane SW8260B 75-69-4 µg/kg nc 3,040,000 99,000 86,000 86,000 8,600 40 30 101,2,3-Trichloropropane SW8260B 96-18-4 µg/kg c 120 17 0.53 0.53 40 40 30 121,2,4-Trimethylbenzene SW8260B 95-63-6 µg/kg nc 510,000 4,900 23,000 4,900 490 40 30 101,3,5-Trimethylbenzene SW8260B 108-67-8 µg/kg nc 510,000 4,200 23,000 4,200 420 40 30 10Vinyl chloride SW8260B 75-01-4 µg/kg c 550 430 8.5 8.5 8.0 8.0 5.0 2.0m- & p-Xylenes SW8260B 179601-23-1 µg/kg nc 59,000 * NS 200 * 200 40 40 30 10o-Xylene SW8260B 95-47-6 µg/kg nc 69,000 * NS 200 * 200 40 40 30 10Xylenes (total) SW8260B 1330-20-7 µg/kg nc 2,030,000 6,300 63,000 6,300 630 80 60 20Polycyclic Aromatic HydrocarbonsAcenaphthene SW8270C SIM 83-32-9 µg/kg nc 280,000 NS 180,000 180,000 18,000 5.0 2.5 1.5Acenaphthylene SW8270C SIM 208-96-8 µg/kg nc 280,000 NS 180,000 180,000 18,000 5.0 2.5 1.5Anthracene SW8270C SIM 120-12-7 µg/kg nc 2,060,000 NS 3,000,000 2,060,000 206,000 5.0 2.5 1.5Benzo(a)anthracene SW8270C SIM 56-55-3 µg/kg c 490 NS 3,600 490 49 5.0 2.5 1.5Benzo(b)fluoranthene SW8270C SIM 205-99-2 µg/kg c 490 NS 12,000 490 49 5.0 2.5 1.5Benzo(k)fluoranthene SW8270C SIM 207-08-9 µg/kg c 4,900 NS 120,000 4,900 490 5.0 2.5 1.5Benzo(g,h,i)perylene SW8270C SIM 191-24-2 µg/kg nc 140,000 NS 38,700,000 140,000 14,000 5.0 2.5 1.5Benzo(a)pyrene SW8270C SIM 50-32-8 µg/kg c 49 NS 2,100 49 5.0 5.0 2.5 1.5Chrysene SW8270C SIM 218-01-9 µg/kg c 49,000 NS 360,000 49,000 4,900 5.0 5.0 1.5Dibenz(a,h)anthracene SW8270C SIM 53-70-3 µg/kg c 49 NS 4,000 49 5.0 5.0 2.5 1.5Fluoranthene SW8270C SIM 206-44-0 µg/kg nc 190,000 NS 1,400,000 190,000 19,000 5.0 2.5 1.5Fluorene SW8270C SIM 86-73-7 µg/kg nc 230,000 NS 220,000 220,000 22,000 5.0 2.5 1.5Indeno(1,2,3-cd)pyrene SW8270C SIM 193-39-5 µg/kg c 490 NS 41,000 490 49 5.0 2.5 1.51-Methylnaphthalene SW8270C SIM 90-12-0 µg/kg nc 28,000 76,000 6,200 6,200 620 5.0 5.0 1.52-Methylnaphthalene SW8270C SIM 91-57-6 µg/kg nc 28,000 75,000 6,100 6,100 610 5.0 5.0 2.0Naphthalene SW8270C SIM 91-20-3 µg/kg nc 140,000 2,800 20,000 2,800 280 5.0 5.0 2.0Phenanthrene SW8270C SIM 85-01-8 µg/kg nc 2,060,000 NS 3,000,000 2,060,000 206,000 5.0 2.5 1.5Pyrene SW8270C SIM 129-00-0 µg/kg nc 140,000 NS 1,000,000 140,000 14,000 5.0 2.5 1.5

Analyte Analytical Method CASRN Units

PAL based on Risk Values 4

Achievable Laboratory Limits

PQL 5c/nc

Page 1 of 2

TABLE 15-1 REFERENCE LIMITS AND PROJECT QUANTITATION LIMITS FOR SOIL, SOURCE AREA ST48, EIELSON AIR FORCE BASE, ALASKA

Screening LevelsRisk-Based

Screening Level (Direct Contact) 1

Screening Level (Outdoor

Inhalation) 2

Cleanup Levels (Migration to

Groundwater) 3LOQ LOD DL


PAL based on Risk Values 4


PQL 5c/nc

Organochlorine PesticidesAldrin SW8081A 309-00-2 µg/kg c 30 NS 70 30 3.0 1.0 0.30 0.22alpha-BHC SW8081A 319-84-6 µg/kg c 120 NS 6.4 6.4 1.0 1.0 0.30 0.28beta-BHC SW8081A 319-85-7 µg/kg c 400 NS 22 22 2.2 1.0 0.50 0.32delta-BHC SW8081A 319-86-8 µg/kg NS NS NS NS 1.0 1.0 0.30 0.15gamma-BHC (Lindane) SW8081A 58-89-9 µg/kg c 560 NS 9.5 9.5 1.0 1.0 0.30 0.30alpha-Chlordane SW8081A 5103-71-9 µg/kg c 1,900 NS 2,300 1,900 190 1.0 0.30 0.13gamma-Chlordane SW8081A 5103-74-2 µg/kg c 1,900 NS 2,300 1,900 190 1.0 0.30 0.134,4-DDD SW8081A 72-54-8 µg/kg c 3,000 NS 7,200 3,000 300 2.0 0.30 0.154,4-DDE SW8081A 72-55-9 µg/kg c 2,100 NS 5,100 2,100 210 2.0 0.30 0.144,4-DDT SW8081A 50-29-3 µg/kg c 2,100 NS 7,300 2,100 210 2.0 0.30 0.15Dieldrin SW8081A 60-57-1 µg/kg c 32 NS 7.6 7.6 2.0 2.0 0.30 0.12Endosulfan I SW8081A 959-98-8 µg/kg nc 61,000 NS 64,000 61,000 6,100 1.0 0.30 0.10Endosulfan II SW8081A 33213-65-9 µg/kg nc 61,000 NS 64,000 61,000 6,100 2.0 0.30 0.17Endosulfan sulfate SW8081A 1031-07-8 µg/kg nc 61,000 NS 64,000 61,000 6,100 2.0 0.30 0.19Endrin SW8081A 72-20-8 µg/kg nc 200 NS 290 200 20 2.0 0.30 0.16Endrin aldehyde SW8081A 7421-93-4 µg/kg nc NS NS NS NS 2.0 2.0 0.30 0.20Endrin ketone SW8081A 53494-70-5 µg/kg nc NS NS NS NS 2.0 2.0 0.50 0.26Heptachlor SW8081A 76-44-8 µg/kg c 130 NS 280 130 13 1.0 0.50 0.46Heptachlor epoxide SW8081A 1024-57-3 µg/kg c 63 NS 14 14 1.4 1.0 0.30 0.0030Methoxychlor SW8081A 72-43-5 µg/kg nc 32,000 NS 23,000 23,000 2,300 10 0.30 0.26Toxaphene SW8081A 8001-35-2 µg/kg c 750 NS 3,900 750 100 100 50 10Polychlorinated Biphenyls (PCBs)Aroclor 1016 8082 12674-11-2 µg/kg nc 390 * NS 92 * 92 10 10 5.0 3.2Aroclor 1221 8082 11104-28-2 µg/kg c 140 * NS 0.12 * 0.12 10 10 8.0 8.0Aroclor 1232 8082 11141-16-5 µg/kg c 140 * NS 0.12 * 0.12 10 10 8.0 7.0Aroclor 1242 8082 53469-21-9 µg/kg c 140 * NS 5.3 * 5.3 10 10 5.0 2.1Aroclor 1248 8082 12672-79-6 µg/kg c 140 * NS 5.2 * 5.2 10 10 3.0 3.0Aroclor 1254 8082 11097-69-1 µg/kg c 140 * NS 8.8 * 8.8 10 10 5.0 2.1Aroclor 1260 8082 11096-82-5 µg/kg c 140 * NS 24 * 24 10 10 5.0 3.0

Total PCBs 8082 1336-36-3 µg/kg c 1,000 NS NS 1,000 100 10 8.0 8.0Total MetalsAluminum SW6010B 7429-90-5 mg/kg nc 7,700 * NS 55,000 * 7,700 770 50 8.9 8.9Antimony SW6020 7440-36-0 mg/kg nc 4.1 NS 3.6 3.6 0.36 0.20 0.080 0.042Arsenic SW6020 7440-38-2 mg/kg c 0.45 NS 3.9 0.45 0.50 0.50 0.40 0.18Barium SW6020 7440-39-3 mg/kg nc 2,030 NS 1,100 1,100 110 0.20 0.040 0.030Beryllium SW6020 7440-41-7 mg/kg c 20 NS 42 20 2.0 0.20 0.040 0.022Cadmium SW6020 7440-43-9 mg/kg c 7.9 NS 5.0 5.0 0.50 0.20 0.020 0.0080Calcium SW6010B 7440-70-2 mg/kg NS NS NS NS 55 55 3.1 3.1Chromium SW6020 7440-47-3 mg/kg nc 30 NS 25 25 2.5 0.20 0.15 0.11Cobalt SW6020 7440-48-4 mg/kg nc 2.3 * NS 0.49 * 0.49 0.20 0.20 0.040 0.019Copper SW6020 7440-50-8 mg/kg nc 410 NS 460 410 41 0.20 0.20 0.098Iron SW6010B 7439-89-6 mg/kg nc 5,500 * NS 640 * 640 64 10 0.61 0.61Lead SW6020 7439-92-1 mg/kg 400 NS NS 400 40 0.20 0.020 0.013Magnesium SW6010B 7439-95-4 mg/kg NS NS NS NS 55 55 3.2 3.2Manganese SW6020 7439-96-5 mg/kg nc 180 * NS 57 * 57 5.7 0.50 0.20 0.17Mercury SW7471A 7439-97-6 mg/kg nc 3.0 1.8 1.4 1.4 0.14 0.020 0.010 0.0063Nickel SW6020 7440-02-0 mg/kg nc 200 NS 86 86 8.6 0.20 0.14 0.20Potassium SW6020 7440-09-7 mg/kg NS NS NS NS 165 165 16 16Selenium SW6020 7782-49-2 mg/kg nc 51 NS 3.4 3.4 0.70 0.70 0.40 0.20Silver SW6020 7440-22-4 mg/kg nc 51 NS 11 11 1.1 0.20 0.020 0.012Sodium SW6010B 7440-23-5 mg/kg NS NS NS NS 100 100 15 15Thallium SW6020 7440-28-0 mg/kg nc 0.81 NS 1.9 0.81 0.50 0.50 0.26 0.13Vanadium SW6020 7440-62-2 mg/kg nc 71 NS 3,400 71 7.1 0.70 0.50 0.47Zinc SW6020 7440-66-6 mg/kg nc 3,040 NS 4,100 3,040 304 2.0 1.5 1.12Total Organic CarbonTotal Organic Carbon SW9060 NS mg/kg NS NS NS NS 2,000 2,000 1,500 608Notes:c - carcinogenic; nc - noncarcinogenicAnalytes shown in bold and blue highlight have a PQL that is higher than the PAL.

2 ADEC Soil Cleanup Levels (2008), 18AAC 75.340 Table B1, Method 2, Outdoor Inhalation, Under 40-inch zone, (corrected for HQ =0.1 and ca = 1 x 10-6 with the exception of TPH).

4 PALs refer to lowest applicable screening levels.5 PQLs are set to 1/10 the PAL, if achievable. If not achievable or there is no specified PAL, the PQL has been established at the LOQ.µg/kg = microgram(s) per kilogram LOQ = limit of quantitationmg/kg = milligram(s) per kilogram. NS = not specifiedCASRN = Chemical Abstracts Service Registry Number PAL = project action limitDL = detection limit PQL = practical quantitation limitHQ - hazard quotient SIM = selected ion monitoringLOD = limit of detection

3 ADEC Soil Cleanup Levels (2008), 18 AAC 75.340 Table B1, Method 2, Migration to Groundwater. If no ADEC cleanup level is available, the appropriate EPA Risk-based Soil Screening Level (June 2011) for protection of groundwater (dilution attenuation factor [DAF]=1) isshown with *. Note that the final evaluation of site data will be made to the lower of the applicable EPA or ADEC criteria.

1 Alaska Department of Environmental Conservation (ADEC) Soil Cleanup Levels (2008), 18 Alaska Administrative Code (AAC) 75.341 Table B1, Method 2, Direct Contact, Under-40 inch zone (corrected for noncarcinogenic risk of HQ = 0.1 and carcinogenic risk level of 1x10-6

with the exception of lead, TPH, and PCBs). If no ADEC cleanup level is available, the appropriate U.S. Environmental Protection Agency (EPA) Regional Screening Level (November 2011) for direct contact is shown with *. The noncarcinogenic RSLs have been corrected for HQ = 0.1; the carcinogenic RSL have not been corrected as the cancer risk is 10-6 as presented at EPA website (http://www.epa.gov/region9/superfund/prg/). Note that the final evaluation of site data will be made to the lower of the applicable EPA or ADEC criteria.

Page 2 of 2

TABLE 15-2 REFERENCE LIMITS AND PROJECT QUANTITATION LIMITS FOR GROUNDWATER, SOURCE AREA ST48, EIELSON AIR FORCE BASE, ALASKA

LOQ LOD DL

Total Petroleum HydrocarbonsGasoline Range Organics (C6 to C10) AK101 NS µg/L nc 2,200 2,200 220 50 44 15Diesel Range Organics (C10 to C25) AK102 NS µg/L nc 1,500 1,500 150 100 60 22Residual Range Organics (C25 to C36) AK103 NS µg/L nc 1,100 1,100 110 100 60 27Volatile Organic Compounds Acetone SW8260B 67-64-1 µg/L nc 33,000 33,000 3,300 10 4.5 1.7Benzene SW8260B 71-43-2 µg/L c 5.0 5.0 1.0 1.0 0.45 0.15Bromobenzene SW8260B 108-86-1 µg/L NS NS 1.0 1.0 0.45 0.15Bromochloromethane SW8260B 74-97-5 µg/L NS NS 1.0 1.0 0.70 0.24Bromodichloromethane SW8260B 75-27-4 µg/L c 14 14 1.4 1.0 0.45 0.15Bromoform SW8260B 75-25-2 µg/L c 110 110 11 1.0 0.45 0.15Bromomethane (Methyl bromide) SW8260B 74-83-9 µg/L nc 51 51 5.1 5.0 2.3 0.752-Butanone (Methyl ethyl ketone) SW8260B 78-93-3 µg/L nc 22,000 22,000 2,200 10 4.5 1.5n-Butylbenzene SW8260B 104-51-8 µg/L nc 370 370 37 1.0 0.45 0.15sec-Butylbenzene SW8260B 135-98-8 µg/L nc 370 370 37 1.0 0.45 0.15t-Butylbenzene SW8260B 98-06-6 µg/L nc 370 370 37 1.0 0.45 0.15Carbon disulfide SW8260B 75-15-0 µg/L nc 3,700 3,700 370 1.0 0.45 0.15Carbon tetrachloride SW8260B 56-23-5 µg/L c 5.0 5.0 1.0 1.0 0.45 0.15Chlorobenzene SW8260B 108-90-7 µg/L nc 100 100 10 1.0 0.45 0.15Chloroethane (Ethyl chloride) SW8260B 75-00-3 µg/L c 290 290 29 5.0 2.3 0.75Chloroform SW8260B 67-66-3 µg/L c 140 140 14 1.0 0.45 0.15Chloromethane (Methyl chloride) SW8260B 74-87-3 µg/L c 66 66 6.6 5.0 2.3 0.752-Chlorotoluene SW8260B 95-49-8 µg/L NS NS 1.0 1.0 0.45 0.154-Chlorotoluene SW8260B 106-43-4 µg/L NS NS 1.0 1.0 0.45 0.151,2-Dibromo-3-chloropropane (DBCP) SW8260B 96-12-8 µg/L NS NS 2.0 2.0 1.5 0.52Dibromochloromethane (Chlorodibromomethane) SW8260B 124-48-1 µg/L c 10 10 1.0 1.0 0.90 0.321,2-Dibromoethane (Ethylene dibromide [EDB]) SW8011 106-93-4 µg/L c 0.050 0.050 0.010 0.010 0.0030 0.0020Dibromomethane (Methylene bromide) SW8260B 74-95-3 µg/L nc 370 370 37 1.0 0.45 0.151,2-Dichlorobenzene SW8260B 95-50-1 µg/L nc 600 600 60 1.0 0.45 0.151,3-Dichlorobenzene SW8260B 541-73-1 µg/L nc 3,300 3,300 330 1.0 0.45 0.151,4-Dichlorobenzene SW8260B 106-46-7 µg/L c 75 75 7.5 1.0 0.45 0.15Dichlorodifluoromethane SW8260B 75-71-8 µg/L nc 7,300 7,300 730 1.0 0.45 0.151,1-Dichloroethane SW8260B 75-34-3 µg/L c 7,300 7,300 730 1.0 0.45 0.151,2-Dichloroethane SW8260B 107-06-2 µg/L c 5.0 5.0 1.0 1.0 0.45 0.151,1-Dichloroethene SW8260B 75-35-4 µg/L c 7.0 7.0 1.0 1.0 0.45 0.151,2-Dichloroethene (cis) SW8260B 156-59-2 µg/L nc 70 70 7.0 1.0 0.45 0.151,2-Dichloroethene (trans) SW8260B 156-60-5 µg/L nc 100 100 10 1.0 0.45 0.151,2-Dichloropropane SW8260B 78-87-5 µg/L c 5.0 5.0 1.0 1.0 0.45 0.151,3-Dichloropropane SW8260B 142-28-9 µg/L NS NS 1.0 1.0 0.45 0.152,2-Dichloropropane SW8260B 594-20-7 µg/L NS NS 1.0 1.0 0.45 0.151,1-Dichloropropene SW8260B 563-58-6 µg/L NS NS 1.0 1.0 0.45 0.151,3-Dichloropropene (cis) SW8260B 10061-01-5 µg/L NS NS 1.0 1.0 0.45 0.151,3-Dichloropropene (trans) SW8260B 10061-02-6 µg/L NS NS 1.0 1.0 0.45 0.151,3-Dichloropropene (total) SW8260B 542-75-6 µg/L c 8.5 8.5 2.0 2.0 0.90 0.30Ethylbenzene SW8260B 100-41-4 µg/L c 700 700 70 1.0 0.45 0.15Hexachlorobutadiene SW8260B 87-68-3 µg/L c 7.3 7.3 1.0 1.0 0.45 0.152-Hexanone SW8260B 591-78-6 µg/L NS NS 5.0 5.0 2.3 0.75Isopropylbenzene (Cumene) SW8260B 98-82-8 µg/L nc 3,700 3,700 370 1.0 0.45 0.15p-Isopropyltoluene SW8260B 99-87-6 µg/L NS NS 1.0 1.0 0.45 0.154-Methyl-2-pentanone (Methyl isobutyl ketone [MIB SW8260B 108-10-1 µg/L nc 2,900 2,900 290 5.0 2.3 0.75Methylene chloride (MeCl2) SW8260B 75-09-2 µg/L c 5.0 5.0 3.0 3.0 0.45 0.15Methyl-tertiary-butyl ether (MtBE) SW8260B 1634-04-4 µg/L c 470 470 48 1.0 0.45 0.15Naphthalene SW8260B 91-20-3 µg/L nc 730 730 73 1.0 0.45 0.15n-Propylbenzene SW8260B 103-65-1 µg/L nc 370 370 37 1.0 0.45 0.15Styrene SW8260B 100-42-5 µg/L nc 100 100 10 1.0 0.45 0.151,1,1,2-Tetrachloroethane SW8260B 630-20-6 µg/L NS NS 1.0 1.0 0.45 0.151,1,2,2-Tetrachloroethane SW8260B 79-34-5 µg/L c 4.3 4.3 1.0 1.0 0.45 0.15Tetrachloroethene (PCE) SW8260B 127-18-4 µg/L c 5.0 5.0 1.0 1.0 0.45 0.15Toluene SW8260B 108-88-3 µg/L nc 1,000 1,000 100 1.0 0.45 0.151,2,3-Trichlorobenzene SW8260B 87-61-6 µg/L NS NS 1.0 1.0 0.45 0.151,2,4-Trichlorobenzene SW8260B 120-82-1 µg/L nc 70 70 7.0 1.0 0.45 0.151,1,1-Trichloroethane SW8260B 71-55-6 µg/L nc 200 200 20 1.0 0.45 0.151,1,2-Trichloroethane SW8260B 79-00-5 µg/L c 5.0 5.0 1.0 1.0 0.45 0.15Trichloroethene (TCE) SW8260B 79-01-6 µg/L c 5.0 5.0 1.0 1.0 0.45 0.15Trichlorofluoromethane SW8260B 75-69-4 µg/L nc 11,000 11,000 1,100 1.0 0.45 0.151,2,3-Trichloropropane SW8260B 96-18-4 µg/L c 0.12 0.12 1.0 1.0 0.45 0.151,2,4-Trimethylbenzene SW8260B 95-63-6 µg/L nc 1,800 1,800 180 1.0 0.45 0.151,3,5-Trimethylbenzene SW8260B 108-67-8 µg/L nc 1,800 1,800 180 1.0 0.45 0.15Vinyl chloride SW8260B 75-01-4 µg/L c 2.0 2.0 1.0 1.0 0.45 0.15m- & p-Xylenes SW8260B 179601-23-1 µg/L NS NS 2.0 2.0 0.90 0.30o-Xylene SW8260B 95-47-6 µg/L NS NS 1.0 1.0 0.45 0.15Xylenes (total) SW8260B 1330-20-7 µg/L nc 10,000 10,000 1,000 3.0 1.4 0.45Volatile Organic Compounds (Field Screening)Benzene SW8265 71-43-2 µg/L c 5.0 5.0 3.0 1.0 to 3.0 -- --1,4-Dichlorobenzene SW8265 106-46-7 µg/L c 75 75 7.5 1.0 to 3.0 -- --1,1-Dichloroethane SW8265 75-34-3 µg/L c 7,300 7,300 730 1.0 to 3.0 -- --1,2-Dichloroethane SW8265 107-06-2 µg/L c 5.0 5.0 3.0 1.0 to 3.0 -- --1,1-Dichloroethene SW8265 75-35-4 µg/L c 7.0 7.0 3.0 1.0 to 3.0 -- --1,2-Dichloroethene (cis) SW8265 156-59-2 µg/L nc 70 70 7.0 1.0 to 3.0 -- --1,2-Dichloroethene (trans) SW8265 156-60-5 µg/L nc 100 100 10 1.0 to 3.0 -- --Ethylbenzene SW8265 100-41-4 µg/L c 700 700 70 1.0 to 3.0 -- --Naphthalene SW8265 91-20-3 µg/L nc 730 730 73 1.0 to 3.0 -- --Tetrachloroethene (PCE) SW8265 127-18-4 µg/L c 5.0 5.0 3.0 1.0 to 3.0 -- --Toluene SW8265 108-88-3 µg/L nc 1,000 1,000 100 1.0 to 3.0 -- --Trichloroethene (TCE) SW8265 79-01-6 µg/L c 5.0 5.0 3.0 1.0 to 3.0 -- --Vinyl chloride SW8265 75-01-4 µg/L c 2.0 2.0 2.0 1.0 to 3.0 -- --Xylenes (total) SW8265 1330-20-7 µg/L nc 10,000 10,000 1,000 1.0 to 3.0 -- --

2008 ADEC Groundwater

Cleanup Levels 1Analyte Analytical

Method CASRN UnitsPAL based on Risk Values 2

Achievable Laboratory LimitsPQL 3c/

nc

Page 1 of 2

TABLE 15-2 REFERENCE LIMITS AND PROJECT QUANTITATION LIMITS FOR GROUNDWATER, SOURCE AREA ST48, EIELSON AIR FORCE BASE, ALASKA

LOQ LOD DL

2008 ADEC Groundwater

Cleanup Levels 1Analyte Analytical

Method CASRN UnitsPAL based on Risk Values 2

Achievable Laboratory LimitsPQL 3c/

nc

Polycyclic Aromatic HydrocarbonsAcenaphthene SW8270C SIM 83-32-9 µg/L nc 2,200 2,200 220 0.10 0.075 0.030Acenaphthylene SW8270C SIM 208-96-8 µg/L nc 2,200 2,200 220 0.10 0.075 0.030Anthracene SW8270C SIM 120-12-7 µg/L nc 11,000 11,000 1,100 0.10 0.075 0.030Benzo(a)anthracene SW8270C SIM 56-55-3 µg/L c 1.2 1.2 0.12 0.10 0.075 0.030Benzo(b)fluoranthene SW8270C SIM 205-99-2 µg/L c 1.2 1.2 0.12 0.10 0.075 0.030Benzo(k)fluoranthene SW8270C SIM 207-08-9 µg/L c 12 12 1.2 0.10 0.075 0.030Benzo(g,h,i)perylene SW8270C SIM 191-24-2 µg/L nc 1,100 1,100 110 0.10 0.075 0.030Benzo(a)pyrene SW8270C SIM 50-32-8 µg/L c 0.20 0.20 0.20 0.20 0.075 0.030Chrysene SW8270C SIM 218-01-9 µg/L c 120 120 12 0.10 0.075 0.030Dibenz(a,h)anthracene SW8270C SIM 53-70-3 µg/L c 0.12 0.12 0.10 0.10 0.075 0.030Fluoranthene SW8270C SIM 206-44-0 µg/L nc 1,500 1,500 150 0.10 0.075 0.030Fluorene SW8270C SIM 86-73-7 µg/L nc 1,500 1,500 150 0.10 0.075 0.030Indeno(1,2,3-cd)pyrene SW8270C SIM 193-39-5 µg/L c 1.2 1.2 0.12 0.10 0.075 0.0301-Methylnaphthalene SW8270C SIM 90-12-0 µg/L nc 150 150 15 0.10 0.075 0.0302-Methylnaphthalene SW8270C SIM 91-57-6 µg/L nc 150 150 15 0.13 0.075 0.030Naphthalene SW8270C SIM 91-20-3 µg/L nc 730 730 73 0.10 0.075 0.036Phenanthrene SW8270C SIM 85-01-8 µg/L nc 11,000 11,000 1,100 0.10 0.075 0.030Pyrene SW8270C SIM 129-00-0 µg/L nc 1,100 1,100 110 0.10 0.075 0.030Total MetalsAluminum SW6010B 7429-90-5 µg/L NS NS 1,000 1,000 930 310Antimony SW6020 7440-36-0 µg/L nc 6.0 6.0 2.0 2.0 1.0 0.40Arsenic SW6020 7440-38-2 µg/L c 10 10 5.0 5.0 3.8 3.8Barium SW6020 7440-39-3 µg/L nc 2,000 2,000 200 6.0 0.50 0.27Beryllium SW6020 7440-41-7 µg/L c 4.0 4.0 2.0 2.0 1.0 0.51Cadmium SW6020 7440-43-9 µg/L c 5.0 5.0 2.0 2.0 0.30 0.14Calcium SW6010B 7440-70-2 µg/L NS NS 1,100 1,100 85 28Chromium SW6020 7440-47-3 µg/L nc 100 100 10 2.0 1.5 1.4Cobalt SW6020 7440-48-4 µg/L NS NS 2.0 2.0 0.30 0.16Copper SW6020 7440-50-8 µg/L nc 1,000 1,000 100 5.0 1.0 0.55Iron SW6010B 7439-89-6 µg/L NS NS 200 200 94 32Lead SW6020 7439-92-1 µg/L c 15 15 2.0 2.0 0.35 0.17Magnesium SW6010B 7439-95-4 µg/L NS NS 1,100 1,100 702 230Manganese SW6020 7439-96-5 µg/L NS NS 2.0 2.0 2.0 0.95Mercury SW7470A 7439-97-6 µg/L nc 2.0 2.0 0.20 0.20 0.10 0.041Nickel SW6020 7440-02-0 µg/L nc 100 100 15 15 2.0 2.0Potassium SW6020 7440-09-7 µg/L NS NS 3,300 3,300 1,200 410Selenium SW6020 7782-49-2 µg/L nc 50 50 5.0 5.0 3.6 3.6Silver SW6020 7440-22-4 µg/L nc 100 100 10 2.0 0.30 0.15Sodium SW6010B 7440-23-5 µg/L NS NS 2,000 2,000 550 180Thallium SW6020 7440-28-0 µg/L nc 2.0 2.0 5.0 5.0 3.0 1.4Vanadium SW6020 7440-62-2 µg/L nc 260 260 26 10 10.0 4.9Zinc SW6020 7440-66-6 µg/L nc 5,000 5,000 500 7.0 5.0 4.4Notes:c - carcinogenic; nc - noncarcinogenicAnalytes shown in bold and blue highlight have a PQL that is higher than the PAL.

2 PALs refer to lowest applicable screening levels.3 PQLs are set to 1/10 the PAL, if achievable. If not achievable or there is no specified PAL, the PQL has been established at the LOQ.µg/L = microgram(s) per liter LOQ = limit of quantitationCASRN = Chemical Abstracts Service Registry Number NS = not specifiedDL = detection limit PAL = project action limitHQ - hazard quotient PQL = practical quantitation limitLOD = limit of detection SIM = selective ion monitoring

1 Alaska Department of Environmental Conservation (ADEC) Groundwater Cleanup Levels (2008), 18 AAC 75.345 Table C.

Page 2 of 2

TABLE 15-3a REFERENCE LIMITS AND PROJECT QUANTITATION LIMITS FOR AIR (INDOOR AIR), SOURCE AREA ST48, EIELSON AIR FORCE, ALASKA

ADEC Residential Indoor Air 1

ADEC Industrial

Indoor Air 1

EPA Indoor Air

2

EPA Residential Air RSL 3

EPA Industrial Air

RSL 3LOQ LOD DL

Volatile Organic Compounds by TO-15Acetone TO-15 67-64-1 µg/m3 nc 3,300 13,800 350 3,200* 14,000* 3,300 330 4.8 1.2 0.54Benzene TO-15 71-43-2 µg/m3 c 0.31 16 31 0.31 1.6 0.31 1.6 1.6 0.64 0.37Bromodichloromethane TO-15 75-27-4 µg/m3 c 0.14 6.9 14 0.066 0.33 0.14 3.4 3.4 1.3 0.45Bromoform TO-15 75-25-2 µg/m3 c 2.2 110 220 2.2 11 2.2 5.2 5.2 2.1 1.1Bromomethane (Methyl bromide) TO-15 74-83-9 µg/m3 nc 5.2 22 5.0 0.52* 2.2* 5.2 1.9 1.9 0.78 0.532-Butanone (Methyl ethyl ketone) TO-15 78-93-3 µg/m3 nc 520 21,900 1,000 520* 2,200* 520 52 5.9 0.59 0.4Carbon tetrachloride TO-15 56-23-5 µg/m3 c 0.16 8.2 16 0.41 2.0 0.16 3.2 3.2 1.3 0.39Chlorobenzene TO-15 108-90-7 µg/m3 nc 52 220 60 5.2 22* 52 5.2 2.3 0.92 0.25Chloroethane (Ethyl chloride) TO-15 75-00-3 µg/m3 nc 29 150 10,000 1,000* 4,400* 29 5.3 5.3 4.2 0.38Chloroform TO-15 67-66-3 µg/m3 c 0.11 5.3 11 0.11 0.53 0.11 2.4 2.4 0.98 0.23Chloromethane (Methyl chloride) TO-15 74-87-3 µg/m3 nc 14 68 90 9.4* 39* 14 4.1 4.1 3.3 1.3Dibromochloromethane (Chlorodibromomethane) TO-15 124-48-1 µg/m3 c 0.10 5.1 10 0.090 0.45 0.10 4.3 4.3 1.7 0.811,2-Dibromoethane (Ethylene dibromide [EDB]) TO-15 106-93-4 µg/m3 c 0.0041 0.20 0.20 0.0041 0.020 0.0041 3.8 3.8 1.5 0.441,2-Dichlorobenzene TO-15 95-50-1 µg/m3 nc 210 880 200 21* 88* 210 3.0 3.0 1.2 0.241,3-Dichlorobenzene TO-15 541-73-1 µg/m3 c 21 880 110 NS NS 21 3.0 3.0 1.2 0.371,4-Dichlorobenzene TO-15 106-46-7 µg/m3 c 0.35 18 800 0.22 1.1 0.35 3.0 3.0 1.2 0.25Dichlorodifluoromethane TO-15 75-71-8 µg/m3 nc 210 880 200 10* 44* 210 2.5 2.5 0.99 0.221,1-Dichloroethane TO-15 75-34-3 µg/m3 c 52 2,200 500 1.5 7.7 52 5.2 2.0 0.81 0.111,2-Dichloroethane TO-15 107-06-2 µg/m3 c 0.094 4.7 9.4 0.094 0.47 0.094 2.0 2.0 0.81 0.341,1-Dichloroethene TO-15 75-35-4 µg/m3 nc 0.49 2.5 200 21* 88* 0.49 2.0 2.0 1.6 0.411,2-Dichloroethene (cis) TO-15 156-59-2 µg/m3 c 3.7 150 NS NS NS 3.7 2.0 2.0 0.79 0.221,2-Dichloroethene (trans) TO-15 156-60-5 µg/m3 nc 63 260 NS 6.3* 26* 63 6.3 2.0 0.79 0.381,2-Dichloropropane TO-15 78-87-5 µg/m3 c 0.13 6.3 4.0 0.24 1.2 0.13 2.3 2.3 0.92 0.321,3-Dichloropropene TO-15 542-75-6 µg/m3 c 0.61 31 20 0.61 3.1 0.61 2.3 2.3 0.91 0.74Ethylbenzene TO-15 100-41-4 µg/m3 c 2.2 110 220 0.97 4.9 2.2 2.2 2.2 0.87 0.24Hexachlorobutadiene TO-15 87-68-3 µg/m3 c 0.11 5.6 11 0.11 0.56 0.11 2.1 2.1 4.3 2.0Isopropylbenzene (Cumene) TO-15 98-82-8 µg/m3 nc 420 1,800 400 42* 180* 420 42 2.5 0.98 0.244-Methyl-2-pentanone (Methyl isobutyl ketone) TO-15 108-10-1 µg/m3 nc 5,200 21,900 80 310* 1,300* 5,200 520 2.1 0.82 0.49Methylene chloride TO-15 75-09-2 µg/m3 c 5.2 260 520 5.2 26 5.2 1.7 1.7 0.69 0.28Methyl-tertiary-butyl ether TO-15 1634-04-4 µg/m3 c 4.7 240 3,000 9.4 47 4.7 1.8 1.8 0.72 0.13Naphthalene TO-15 91-20-3 µg/m3 c 0.072 3.6 3.0 NS NS 0.072 10 10 8.4 0.14n-Propylbenzene TO-15 103-65-1 µg/m3 nc 37 150 140 100* 440* 37 3.7 2.5 0.98 0.25Styrene TO-15 100-42-5 µg/m3 nc 1,000 4,400 1,000 100* 440* 1,000 100 2.1 1.7 0.431,1,2,2-Tetrachloroethane TO-15 79-34-5 µg/m3 c 0.042 2.1 4.2 0.042 0.21 0.042 3.4 3.4 1.37 0.41Tetrachloroethene (PCE) TO-15 127-18-4 µg/m3 c 0.41 21 81 0.41 2.1 0.41 3.4 3.4 1.36 0.22Toluene TO-15 108-88-3 µg/m3 nc 5,200 21,900 400 520* 2,200* 5,200 520 1.9 0.75 0.301,2,4-Trichlorobenzene TO-15 120-82-1 µg/m3 nc 4.2 18 200 0.21* 0.88 * 4.2 15 15 3.0 0.741,1,1-Trichloroethane TO-15 71-55-6 µg/m3 nc 2,300 9,600 2,200 520* 2,200* 2,300 230 2.7 1.1 0.321,1,2-Trichloroethane TO-15 79-00-5 µg/m3 c 0.15 7.7 15 0.15 0.77 0.15 2.7 2.7 1.1 0.44Trichloroethene (TCE) TO-15 79-01-6 µg/m3 c/nc 0.022 1.1 2.3 0.21 * 0.88 * 0.022 2.7 2.7 1.1 0.29Trichlorofluoromethane TO-15 75-69-4 µg/m3 nc 73 3,100 700 73* 310 * 73 7.3 2.8 1.1 0.301,2,4-Trimethylbenzene TO-15 95-63-6 µg/m3 nc 7.3 31 6.0 0.73* 3.1* 7.3 2.5 2.5 0.98 0.361,3,5-Trimethylbenzene TO-15 108-67-8 µg/m3 c 0.73 31 6.0 NS NS 0.73 2.5 2.5 0.98 0.46Vinyl chloride TO-15 75-01-4 µg/m3 c 0.081 1.1 28 0.16 2.8 0.081 1.3 1.3 1.0 0.16m- & p-Xylenes TO-15 1330-20-7 µg/m3 nc NS NS 7,000 10* 44* 10 2.2 2.2 0.87 0.16o-Xylene TO-15 95-47-6 µg/m3 nc NS NS 7,000 10* 44* 10 2.2 2.2 0.87 0.31Xylenes (total) TO-15 1330-20-7 µg/m3 nc 10 440 NS 10* 44* 10 2.2 2.2 0.87 0.47Volatile Organic Compounds by TO-15 using SIM modeBenzene TO-15 SIM 71-43-2 µg/m3 c 0.31 16 31 0.31 1.6 0.31 0.16 0.16 0.013 0.00601,1-Dichloroethane TO-15 SIM 75-34-3 µg/m3 c 52 2200 500 1.5 7.7 52 5.2 0.082 0.016 0.00401,2-Dichloroethane TO-15 SIM 107-06-2 µg/m3 c 0.094 4.7 9.4 0.094 0.47 0.094 0.082 0.082 0.032 0.00401,1-Dichloroethene TO-15 SIM 75-35-4 µg/m3 nc 0.49 2.5 200 21* 88* 0.49 0.049 0.040 0.016 0.00801,2-Dichloroethene (cis) TO-15 SIM 156-59-2 µg/m3 c 3.7 150 NS NS NS 3.7 0.37 0.080 0.016 0.00401,2-Dichloroethene (trans) TO-15 SIM 156-60-5 µg/m3 nc 63 260 NS 6.3* 26* 63 6.3 0.40 0.016 0.0080Ethylbenzene TO-15 SIM 100-41-4 µg/m3 c 2.2 110 220 0.97 4.9 2.2 0.22 0.088 0.017 0.0040Methyl-tertiary-butyl ether TO-15 SIM 1634-04-4 µg/m3 c 4.7 240 3,000 9.4 47 4.7 0.47 0.37 0.014 0.00401,1,2,2-Tetrachloroethane TO-15 SIM 79-34-5 µg/m3 c 0.042 2.1 4.2 0.042 0.21 0.042 0.14 0.14 0.028 0.021Tetrachloroethene (PCE) TO-15 SIM 127-18-4 µg/m3 c 0.41 21 81 0.41 2.1 0.41 0.14 0.14 0.027 0.0070Toluene TO-15 SIM 108-88-3 µg/m3 nc 5,200 21,900 400 520* 2,200* 5,200 520 0.076 0.015 0.00801,1,1-Trichloroethane TO-15 SIM 71-55-6 µg/m3 nc 2,300 9,600 2,200 520* 2,200* 2,300 230 0.11 0.022 0.0111,1,2-Trichloroethane TO-15 SIM 79-00-5 µg/m3 c 0.15 7.7 15 0.15 0.77 0.15 0.11 0.11 0.022 0.011Trichloroethene (TCE) TO-15 SIM 79-01-6 µg/m3 c/nc 0.022 1.1 2.3 0.21 * 0.88 * 0.022 0.11 0.11 0.022 0.011Vinyl chloride TO-15 SIM 75-01-4 µg/m3 c 0.081 1.1 28 0.16 2.8 0.081 0.026 0.026 0.020 0.0050m- & p-Xylenes TO-15 SIM 1330-20-7 µg/m3 nc NS NS 7,000 10* 44* 10 1.0 0.18 0.017 0.0090o-Xylene TO-15 SIM 95-47-6 µg/m3 nc NS NS 7,000 10* 44* 10 1.0 0.088 0.017 0.0090Xylenes (total) TO-15 SIM 1330-20-7 µg/m3 nc 10 440 NS 10* 44* 10 1.0 0.18 0.017 0.0090Notes:

c - carcinogen; nc - noncarcinogenic1 Alaska Department of Environmental Conservation (ADEC) Draft Vapor Intrusion Guidelines for Contaminated Sites (2009), Appendix D: Target Levels for Indoor Air. Values have been adjusted to HQ =0.1 ca = 1 x 10-6 when necessary.2 U.S. Environmental Protection Agency Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils (Subsurface Vapor Intrusion Guidance), November 2002.3 EPA Regional Screening Levels updated November 2011, accessed from http://www.epa.gov/reg3hwmd/risk/human/rb-concentration_table/Generic_Tables/index.htm on 09 December 2011.4 Project action levels (PALs) selected based on the lowest ADEC values, if listed. If not listed, the RSLs have been selected. Note that the final evaluation of site data will be made to the lower of the applicable EPA or ADEC criteria.5 Project quantification limits (PQLs) are set to 1/10 the PAL, if achievable. If not achievable, the PQLs are set at the LOQ.

* Noncancer RSLs divided by 10 to account for additivity.µg/m3 = microgram(s) per cubic meter NS = not specified

CASRN = Chemical Abstracts Service Registry Number PAL = project action limit

DL = detection limit PQL = practical quantitation limit

LOQ = limit of quantitation RSL = Regional Screening Levels

LOD = limit of detection SIM = selected ion monitoringHighlighted and bold cells indicate those analytes for which the laboratory is not able to achieve the PAL, and the laboratory LOQ has been shown as the PQL.

carc

inog

enic

(c

/nc)


PQL 5Analyte Analytical Method CASRN Units PAL 4

INDOOR AIR

Page 1 of 1

TABLE 15-3b REFERENCE LIMITS AND PROJECT QUANTITATION LIMITS FOR AIR (SUBSLAB AND SOIL GAS), SOURCE AREA ST48, EIELSON AIR FORCE, ALASKA

ADEC Industrial

Shallow or Subslab Soil

Gas 1

ADEC Industrial Deep Soil

Gas 2

ADEC Residential Shallow or

Subslab Soil Gas 1

ADEC Residential Deep Soil

Gas 2

EPA Shallow or Subslab Soil Gas 3

EPA Deep Soil Gas 3 LOQ LOD DL

Volatile Organic Compounds by TO-15Acetone TO-15 67-64-1 µg/m3 nc 138,000 1,380,000 32,900 329,000 3,500 35,000 32,900 3,290 4.8 1.2 0.54Benzene TO-15 71-43-2 µg/m3 c 160 1,600 31 310 310 3,100 31 3.1 1.6 0.64 0.37Bromodichloromethane TO-15 75-27-4 µg/m3 c 69 690 14 140 140 1,400 14 3.4 3.4 1.3 0.45Bromoform TO-15 75-25-2 µg/m3 c 1,100 11,000 220 2,200 2,200 22,000 220 22 5.2 2.1 1.1Bromomethane (Methyl bromide) TO-15 74-83-9 µg/m3 nc 1,500 2,200 370 520 50 500 370 37 1.9 0.78 0.532-Butanone (Methyl ethyl ketone) TO-15 78-93-3 µg/m3 nc 219,000 2,190,000 52,100 521,000 10,000 100,000 52,100 5,210 5.9 0.59 0.4Carbon tetrachloride TO-15 56-23-5 µg/m3 c 82 820 16 160 160 1,600 16 3.2 3.2 1.3 0.39Chlorobenzene TO-15 108-90-7 µg/m3 nc 2,200 22,000 520 5,200 600 6,000 520 52 2.3 0.92 0.25Chloroethane (Ethyl chloride) TO-15 75-00-3 µg/m3 nc 1,500 15,000 290 2,900 100,000 1,000,000 290 29 5.3 4.2 0.38Chloroform TO-15 67-66-3 µg/m3 c 53 530 11 110 110 1,100 11 2.4 2.4 0.98 0.23Chloromethane (Methyl chloride) TO-15 74-87-3 µg/m3 nc 680 6,800 140 1,400 900 9,000 140 14 4.1 3.3 1.3Dibromochloromethane (Chlorodibromomethane) TO-15 124-48-1 µg/m3 c 51 510 10 100 100 1,000 10 4.3 4.3 1.7 0.811,2-Dibromoethane (Ethylene dibromide [EDB]) TO-15 106-93-4 µg/m3 c 2.0 20 0.41 4.1 2.0 20 0.41 3.8 3.8 1.5 0.441,2-Dichlorobenzene TO-15 95-50-1 µg/m3 nc 8,800 88,000 2,100 21,000 2,000 20,000 2,100 210 3.0 1.2 0.241,3-Dichlorobenzene TO-15 541-73-1 µg/m3 c 8,800 88,000 2,100 21,000 1,100 11,000 2,100 210 3.0 1.2 0.371,4-Dichlorobenzene TO-15 106-46-7 µg/m3 c 180 1,800 35 350 8,000 80,000 35 3.5 3.0 1.2 0.25Dichlorodifluoromethane TO-15 75-71-8 µg/m3 nc 8,800 88,000 2,100 21,000 2,000 20,000 2,100 210 2.5 0.99 0.221,1-Dichloroethane TO-15 75-34-3 µg/m3 c 21,900 219,000 5,200 52,000 5,000 50,000 5,200 520 2.0 0.81 0.111,2-Dichloroethane TO-15 107-06-2 µg/m3 c 47 470 9.4 94 94 940 9.4 2.0 2.0 0.81 0.341,1-Dichloroethene TO-15 75-35-4 µg/m3 nc 25 250 4.9 49 2,000 20,000 4.9 2.0 2.0 1.6 0.411,2-Dichloroethene (cis) TO-15 156-59-2 µg/m3 c 1,500 15,000 370 3,700 NS NS 370 37 2.0 0.79 0.221,2-Dichloroethene (trans) TO-15 156-60-5 µg/m3 nc 2,600 26,000 630 6,300 NS NS 630 63 2.0 0.79 0.381,2-Dichloropropane TO-15 78-87-5 µg/m3 c 63 630 13 130 40 400 13 2.3 2.3 0.92 0.321,3-Dichloropropene TO-15 542-75-6 µg/m3 c 310 3,100 61 610 200 2,000 61 6.1 2.3 0.91 0.74Ethylbenzene TO-15 100-41-4 µg/m3 c 1,100 11,000 220 2,200 2,200 22,000 220 22 2.2 0.87 0.24Hexachlorobutadiene TO-15 87-68-3 µg/m3 c 56 560 11.1 111 110 1,100 11.1 2.1 2.1 4.3 2.0Isopropylbenzene (Cumene) TO-15 98-82-8 µg/m3 nc 17,500 175,000 4,200 42,000 4,000 40,000 4,200 420 2.5 0.98 0.244-Methyl-2-pentanone (Methyl isobutyl ketone) TO-15 108-10-1 µg/m3 nc 131,000 1,310,000 31,300 313,000 800 8,000 31,300 3,130 2.1 0.82 0.49Methylene chloride TO-15 75-09-2 µg/m3 c 2,600 26,000 520 5,200 5,200 52,000 520 52 1.7 0.69 0.28Methyl-tertiary-butyl ether TO-15 1634-04-4 µg/m3 c 2,400 24,000 470 4,700 30,000 300,000 470 47 1.8 0.72 0.13Naphthalene TO-15 91-20-3 µg/m3 c 36 360 7.2 72 300 3,000 7.2 10 10 8.4 0.14n-Propylbenzene TO-15 103-65-1 µg/m3 nc 1,500 15,000 370 3,700 1,400 14,000 370 37 2.5 0.98 0.25Styrene TO-15 100-42-5 µg/m3 nc 43,800 438,000 10,400 104,000 10,000 100,000 10,400 1,040 2.1 1.7 0.431,1,2,2-Tetrachloroethane TO-15 79-34-5 µg/m3 c 21 210 4.2 42 42 420 4.2 3.4 3.4 1.37 0.41Tetrachloroethene (PCE) TO-15 127-18-4 µg/m3 c 210 2,100 41 410 810 8,100 41 3.4 3.4 1.36 0.22Toluene TO-15 108-88-3 µg/m3 nc 219,000 2,190,000 52,100 521,000 4,000 40,000 52,100 5,210 1.9 0.75 0.301,2,4-Trichlorobenzene TO-15 120-82-1 µg/m3 nc 180 1,800 42 420 2,000 20,000 42 15 15 3.0 0.741,1,1-Trichloroethane TO-15 71-55-6 µg/m3 nc 96,400 964,000 22,900 229,000 22,000 220,000 22,900 2,290 2.7 1.1 0.321,1,2-Trichloroethane TO-15 79-00-5 µg/m3 c 77 770 15 150 150 1,500 15 2.7 2.7 1.1 0.44Trichloroethene (TCE) TO-15 79-01-6 µg/m3 c 11 110 2.2 22 22 220 2.2 2.7 2.7 1.1 0.29Trichlorofluoromethane TO-15 75-69-4 µg/m3 nc 30,700 307,000 730 7,300 7,000 70,000 730 73 2.8 1.1 0.301,2,4-Trimethylbenzene TO-15 95-63-6 µg/m3 nc 310 3,100 73 730 60 600 73 7.3 2.5 0.98 0.361,3,5-Trimethylbenzene TO-15 108-67-8 µg/m3 c 310 3,100 73 730 60 600 73 7.3 2.5 0.98 0.46Vinyl chloride TO-15 75-01-4 µg/m3 c 11 110 8.1 81 280 2,800 8.1 1.3 1.3 1.0 0.16m- & p-Xylenes TO-15 1330-20-7 µg/m3 nc NS NS NS NS 70,000 700,000 70,000 7,000 2.2 0.87 0.16o-Xylene TO-15 95-47-6 µg/m3 nc NS NS NS NS 70,000 700,000 70,000 7,000 2.2 0.87 0.31Xylenes (total) TO-15 1330-20-7 µg/m3 nc 4,400 44,000 1,000 10,000 NS NS 1,000 100 2.2 0.87 0.47Notes:c - carcinogen; nc - noncarcinogenic1 ADEC Draft Vapor Intrusion Guidelines for Contaminated Sites (2009), Appendix E: Target Levels for Shallow or Subslab Soil Gas.2 ADEC Draft Vapor Intrusion Guidelines for Contaminated Sites (2009), Appendix E: Target Levels for Deep Soil Gas3 U.S. Environmental Protection Agency Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils (Subsurface Vapor Intrusion Guidance), November 2002.

4 Project action levels (PALs) selected based on the lowest ADEC values, if listed. If not listed, the EPA values have been selected. Note that the final evaluation of site data will be made to the lower of the applicable EPA or ADEC criteria.5 Project quantification limits (PQLs) are set to 1/10 the PAL, if achievable. If not achievable, the PQLs are set at the LOQ.µg/m3 = microgram(s) per cubic meter NS = not specifiedCASRN = Chemical Abstracts Service Registry Number PAL = project action limitDL = detection limit PQL = practical quantitation limitLOQ = limit of quantitation SIM = selected ion monitoringLOD = limit of detectionHighlighted and bold cells indicate those analytes for which the laboratory is not able to achieve the PAL, and the laboratory LOQ has been shown as the PQL.

PAL 4 PQL 5

Achievable Laboratory LimitsSUBSLAB AND SOIL GAS


carc

inog

enic

(c

/nc)

Page 1 of 1

TABLE 15-4 EVALUATION APPROACH FOR COMPOUNDS FOR WHICH PALS EXCEED VARIOUS LABORATORY LIMITS SOURCE AREA ST48, EIELSON AIR FORCE, ALASKA

Analyte LOQ> PAL>LOD LOD> PAL>DL DL>PALHistorically

Detected in Any Medium at ST48

Potentially Associated with Historical ST48

Operations

Potentially Associated with

Upgradient Source 1

Relevance to ST48 Investigation, by medium

Approach to determine if various laboratory limits higher than screening levels constitute a data gap for specific

compounds at ST48 2

Groundwater

1,2,3‐Trichloropropane ‐‐ ‐‐ X No No No

No historical detections at the site. Furthermore, it has not been

associated with any of the historical site activities or with activities at the

upgradient potential source.

Not applicable; not a data gap.

Thallium ‐‐ X ‐‐ No Possible No

Retained conservatively as it may have been associated with activities at the

power plant.

After background evaluation, results will be compared first to background values.

Not a data gap.

Soil

Bromochloromethane ‐‐ X ‐‐ No No




Not applicable. Because it is not a site COC, a site‐specific screening level will not

be calculated; however, the analytical method is adequate to show

presence/absence of this compound in groundwater. Not a data gap.

Chloromethane (Methyl chloride) ‐‐ X ‐‐ X (GW)

Possible, detected in

groundwater

Detected in groundwater at the site. Presence in groundwater may be due

to migration from impacted soil at ST48, from migration through

groundwater from the dry well, or reductive dechlorination of carbon

tetrachloride. Retained conservatively.

Only an issue for soil to groundwater migration pathway, for which site‐specific

screening level value will be calculated. The analytical method is adequate to show


1,2‐Dibromo‐3‐chloropropane (DBCP)

‐‐ ‐‐ X No No





be calculated. Not a data gap.

Dibromochloromethane (Chlorodibromomethane)

X ‐‐ ‐‐ No No





be calculated. The analytical method is adequate to show presence/absence of this compound in groundwater. Not a

data gap.

1,2‐Dibromoethane (Ethylene dibromide [EDB])

‐‐ ‐‐ X X (GW)Gasoline and

AvGas Additive


to migration from impacted soil at ST48.

LOD only exceeds the screening level for soil to groundwater migration pathway. Currently, an analytical method that can

achieve lower detection limits for this compound is not available, although the

analytical laboratory is working on developing Method SW8011 for soil. A

site‐specific screening level will be calculated for this compound. The

analytical method is adequate to show presence/absence of this compound in

groundwater. Not a data gap.

1,2‐Dichloroethane (EDC) ‐‐ X ‐‐ X (GW)Gasoline and

AvGas Additive


to migration from impacted soil at ST48. Retained conservatively.

Only exceeds the screening level for soil to groundwater migration pathway.

Currently, an analytical method that can achieve lower detection limits for this

compound is not available. The analytical method is adequate to show


2‐Hexanone ‐‐ ‐‐ X No No




Not applicable. LOD is only higher than the screening level for soil to groundwater migration pathway. Because it is not a site COC, a site‐specific screening level will not

be calculated. However, the analytical method is adequate to show

presence/absence of this compound in groundwater.

Methylene chloride ‐‐ X ‐‐ X (GW)

Possible, detected in

groundwater

Presence in groundwater can be due to migration from impacted soil at

ST48, from migration through groundwater from the dry well, or from reductive dechlorination of carbon tetrachloride. Retained

conservatively.


screening level value can be calculated. The analytical method is adequate to show


1,1,1,2‐Tetrachloroethane ‐‐ ‐‐ X No Possible Retain conservatively


screening level value will be calculated. The analytical method is adequate to show


1,2,3‐Trichloropropane ‐‐ ‐‐ X No No




Not applicable. DL is only higher than the screening level for soil to groundwater

migration pathway. Because it is not a site COC, a site‐specific screening level will not

be calculated.

Aroclor 1221 ‐‐ ‐‐ X NoAroclor 1232 ‐‐ ‐‐ X No

Aroclor 1242 X ‐‐ ‐‐ No

Aroclor 1248 X ‐‐ ‐‐ No

PAL is higher than various laboratory limits: Compound is:

Other Aroclors besides 1254 may be present at ST48. Multiple Aroclors are analyzed with the proposed analytical

method.

Transformers were present at

ST48

Possible, migration from this

upgradient source to ST48 through

groundwater

Only an issue for soil to groundwater migration pathway for EPA screening

levels, for which site‐specific screening

Page 1 of 3





Operations


Upgradient Source 1



compounds at ST48 2


Aroclor 1254 X ‐‐ ‐‐ X (S) Detected in soil Detected in soil at ST48.

level value will be calculated. The State of Alaska has a screening level promulgated for total PCBs but not for individual Aroclors. The proposed analytical method has an adequate LOQ for comparison to the Alaska screening level for total PCBs. Not a data gap.

Arsenic X ‐‐ ‐‐ X (GW, S)Detected in soil

and groundwater

Possible impact due to storage of coal and ash deposition. Current background levels unknown

(background is in the process of being evaluated). Retained conservatively.

Exceeds the screening level for direct contact only. Comparison will be first performed to background value, once

available, which is anticipated to exceed the LOQ for this metal. Not a data gap.

Subslab Air


‐‐ ‐‐ X X (GW)Detected in

groundwater

Possible, migration from upgradient source to ST48

through groundwater


to migration from impacted soil at ST48. Retained conservatively.

The DL is only higher than the screening level for the residential scenario. No buildings are currently adequate for residential use, so although future

residential occupancy is possible, there are no residences available for testing at this

time. Not a data gap.

Trichloroethene (TCE) X ‐‐ ‐‐ X (GW)Detected in

groundwater


through groundwater.

Yes

The LOQ is only higher than the screening level for the residential scenario. No buildings are currently adequate for residential use, so although future

residential occupancy is possible, there are no residences available for testing at this

time.

Bromodichloromethane ‐‐ ‐‐ X No No No No

Not applicable. Not considered a data gap due to no known association with this site or upgradient potential source. DL only higher than ADEC and EPA residential air and EPA industrial air. Residential use is

not applicable to current use of buildings. Not included in the suite for TO‐15 SIM.

Bromoform X ‐‐ ‐‐ No No No No

Not applicable. LOQ only higher than ADEC and EPA residential air, not

applicable to current use of buildings. Not included in the suite for TO‐15 SIM. Not a

data gap.

Carbon tetrachloride ‐‐ ‐‐ X No No No




Not applicable. Not considered a data gap due to no known association with this site or upgradient potential source. DL only higher than ADEC residential indoor air,


Chloroform ‐‐ ‐‐ X X (GW)Detected in

groundwater


through groundwater

Yes

DL is only higher than ADEC and EPA residential screening levels, that are

applicable only to buildings designed for residential use. Not included in the suite

for TO‐15 SIM. Not a data gap.

Dibromochloromethane (Chlorodibromomethane)

‐‐ ‐‐ X No No No




Not applicable to ST48. DL only higher than ADEC and EPA residential, and EPA

industrial, air screening levels. Not included in the suite for TO‐15 SIM. Not a

data gap.


‐‐ ‐‐ X X (GW)Detected in

groundwater


through groundwater

Yes

DL is higher than all screening levels. This compound is not included in the suite for TO‐15 SIM, so no lower detection limits

can be achieved with the proposed analytical method. However, due to the

much smaller percent content of EDB compared to BTEX compounds in gasoline, it is likely that the risk for all scenarios will

be driven by an exposure from BTEX compounds rather than EDB. EDB will not be solely present at a site unless it is in the

leading edge of the plume (because it is more mobile than BTEX compounds). In the leading edge of the plume, it will be

present at low concentrations. Not a data gap.

1,4‐Dichlorobenzene ‐‐ X ‐‐ X (GW)Detected in

groundwaterNo

Retained due to presence in groundwater.

DL is only higher than ADEC and EPA residential screening levels, that are not applicable to buildings not designed for

residential use. Not a data gap. Not included in the suite for TO‐15 SIM.

1,2‐Dichloropropane ‐‐ ‐‐ X No No No




Not applicable. Not considered a data gap due to no known association with this site

or upgradient potential source. DL only higher than ADEC residential indoor air,

not applicable to current use of buildings.

Indoor Air


through groundwater

Page 2 of 3





Operations


Upgradient Source 1



compounds at ST48 2


1,3‐Dichloropropene ‐‐ ‐‐ X No No No







Hexachlorobutadiene ‐‐ ‐‐ X No No No







Naphthalene ‐‐ ‐‐ X X (GW, S)Detected in

groundwater


through groundwater

Retained due to presence in groundwater.

DL is only higher than ADEC residential screening level, that is not applicable to

buildings not designed for residential use. Not included in the suite for TO‐15 SIM.

Not a data gap.

1,1,2,2‐Tetrachloroethane ‐‐ X ‐‐ No No No




Not applicable to ST48. DL only higher than ADEC and EPA residential and EPA

industrial air screening levels. Not included in the suite for TO‐15 SIM. Not a

data gap.

1,2,4‐Trichlorobenzene X ‐‐ ‐‐ No No No





or upgradient potential source. DL only higher than EPA residential air, not

applicable to current use of buildings. Not included in the suite for TO‐15 SIM.

TCE X ‐‐ ‐‐ X (GW)Detected in

groundwater


through groundwater

Yes

LOD is only equal or higher than ADEC and EPA residential screening levels, that are not applicable to buildings not designed

for residential use. Not a data gap.

1,3,5‐Trimethylbenzene ‐‐ X ‐‐ X (GW)Detected in

groundwaterNo Yes

LOQ is only higher than ADEC residential screening level, that is not applicable to

buildings not designed for residential use. Not included in the suite for TO‐15 SIM.

Not a data gap.

Notes:

X = true DL = detection limit

‐‐ = false LOD = limit of detection

GW = analyte detected in groundwater samples collected at the site. LOQ = limit of quantitation

S = analyte detected in soil samples collected at the site. PAL = project action limit

1 Note that contaminants detected in groundwater and associated with the upgradient dry well would not be expected in site soil.2 While residential indoor air screening levels are not considered applicable for existing site buildings, if residential buildings are constructed at the site in the future, indoor air sampling and/or mitigation measures may be appropriate at that time.

Page 3 of 3

QAPP Worksheet #16 Title: Site Specific QAPPforSource Area ST48 Project Schedule/Timeline Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 16-1

QAPP WORKSHEET #16 PROJECT SCHEDULE/TIMELINE TABLE

Activities Organization

Dates (MM/DD/YY)

Deliverable Deliverable Due Date

(MM/DD/YY) Anticipated Date(s)

of Intiation Anticipated Dates

of Completion UFP QAPP ST48 – Draft EA 6/16/11 7/22/11 Report-Draft 7/22/11 UFP QAPP ST48 – Draft/Final EA 8/22/11 9/23/2011 Report-Draft Final 9/23/2011 UFP QAPP ST48 – Draft Final V.2 EA 12/15/2011 1/14/2012 Report – Draft Final

V.2 1/14/2012

UFP QAPP ST48 – Final EA 2/13/2012 3/14/2012 Report- Final 3/14/2012 Initiation of Field Effort EA 5/1/2012 TBD Field Effort TBD NOTES:

1. Received 20-day extension from EPA and ADEC for Draft/Final. 2. TBD = to be determined.

QAPP Worksheet #16 Title: Site Specific QAPPforSource Area ST48 Project Schedule/Timeline Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 16-2


QAPP Worksheet #17 Title: Site Specific QAPP for Source Area ST48 Sample Design and Rationale Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 17-1

QAPP WORKSHEET #17 SAMPLE DESIGN AND RATIONALE Conceptual Site Model: The CSM for this source area is presented and discussed in Worksheet #10 and depicted on Figure 10-6. Describe and provide a rationale for choosing the sampling approach (e.g., grid system, biased statistical approach): A biased approach will be used to evaluate the current extent of soil, groundwater, and potentially air contamination at the site. Following sampling of existing site monitoring wells, direct push soil and groundwater samples will be collected from areas of known impacts to document the current contaminant concentrations. Additional direct push samples will be collected to evaluate the extent of site COCs by stepping out from the source areas. After evaluation of the direct push analytical data, air sampling will be performed if needed, in accordance with ADEC vapor intrusion guidelines, and additional monitoring wells will be installed. Following is the technical approach to be used for each stage of the field work.

1. Baseline groundwater sampling of existing monitoring wells;

a. The four existing monitoring wells at the site will be surveyed to create a common reference.

b. The existing wells will be gauged for use in determining the direction of

groundwater flow at the site. c. Groundwater samples will be collected from the existing wells.

2. Soil and groundwater plume delineation;

a. Sampling locations will be selected based on previous soil and groundwater data.

Due to the limited number of existing wells and the varying depths of those wells, the groundwater samples will be of limited use in guiding the soil and groundwater plume delineation activities.

b. Direct push borings will be advanced to depths of up to 15 ft bgs within the grid

area identified on Figure 11-1. Continuous soil cores will be collected. Using the Triad approach, direct push sampling locations will be stepped outward


Page 17-2

(downgradient and cross-gradient) until one or more “clean” (groundwater concentrations less than 1 µg/L benzene, based on field screening using the field laboratory) locations are sampled.

c. Two soil samples will be submitted for laboratory analysis from each direct push

boring, one from a depth between 0 and 2 ft bgs and the other from a depth between 2 ft bgs and the water table. The samples will be collected from the interval exhibiting the greatest potential contamination, based on field screening using a photoionization detector (PID). Soil samples will be submitted to an offsite laboratory for analysis.

d. One or more groundwater samples will be collected from each direct push boring

at depths below the water table. Groundwater samples will be submitted to the field laboratory for VOC analysis, with selected samples also submitted to the offsite laboratory for confirmation, as described in Worksheet #14. Non-VOC analyses will be performed by the offsite laboratory as described in Worksheet #14.

e. The presence of NAPL in the capillary fringe zone will be evaluated by use of a

field dye test kit (OilScreenSoil™ or similar). f. For transformer sites, soil sampling locations will be selected based on a records

search. Two soil samples will be collected from each identified transformer location: one from surface soil (0 to 2 ft bgs) and one from subsurface soil (2 ft bgs to the water table).

g. Laboratory results for the soil and groundwater samples will be used to evaluate

the current concentrations and extent of contamination at the site.

3. Soil sampling for hydrogeologic characterization;

a. Soil samples will be collected from selected direct push borings and submitted for laboratory analysis of soil physical characteristics.

b. Soil samples for physical analysis will be selected from borings/depths outside of

the contaminated area.

4. Evaluate indoor air pathway, if needed; a. Indoor air and/or sub-slab soil gas samples will be collected in and beneath

occupied buildings present within the contaminant plume area.

b. Air samples will be compared to screening levels to determine if the air pathway is complete.


Page 17-3

c. Outdoor air samples will also be collected for use in evaluating the ambient background air concentration.

5. Monitoring well installation;

a. After plume delineation, permanent monitoring well locations will be selected in

areas where coverage is not available by existing wells. Up to five monitoring wells with screens intersecting the water table will be installed to delineate the horizontal extent of the plume or to monitor contaminant concentrations in the source area(s). One deeper well will be used to determine the vertical extent of the plume. The depth of this well will be determined based on the results of the vertical delineation sampling during the direct push groundwater investigation.

b. Groundwater samples will be collected from the existing and new monitoring

wells to characterize groundwater quality and plume characteristics. These wells will be used to generate reproducible long term data.

Describe the sampling design and rationale in terms of what matrices will be sampled, what analytical groups will be analyzed and at what concentration levels, the sampling locations (including QC, critical, and background samples), the number of samples to be taken, and the sampling frequency (including seasonal considerations): To reduce redundancy, only general information on how decisions are to be made regarding these elements is presented in this worksheet. Worksheet #11, Table 11-1 provides additional sampling design and rationale regarding:

• Matrices and associated suites of analytes, • Expected concentration levels, and • Types and number of field and laboratory QC samples applicable to the site.

Sampling locations are shown on Figure 11-1. Additional details regarding sequence and progression of the assessment, sample locations, and numbers are provided in Worksheet #14. This investigation will be performed using the Triad process where all stakeholders have input in the decision making process to guide the investigation toward a common goal – complete delineation and optimally the protection of human health and the environment. As such, the data and analysis will progress from existing data review, to collection of definitive soil data and both screening level and definitive groundwater data, followed by monitoring well installation and definitive groundwater data collection. Specific details on sampling decision processes are presented in Worksheet #10, Worksheet # 11 and Worksheet #14.


Page 17-4


QAPP Worksheet #18 Title: Site Specific QAPP for Source Area ST48 Sampling Locations and Methods/ Revision Number: 0 SOP Requirements Table Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 18-1

QAPP WORKSHEET #18 SAMPLING LOCATIONS AND METHODS/SOP REQUIREMENTS TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #18 Title: Site Specific QAPP for Source Area ST48 Sampling Locations and Methods/ Revision Number: 0 SOP Requirements Table Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 18-2


QAPP Worksheet #19 Title: Site Specific QAPP for Source Area ST48 Analytical SOP Requirements Tables Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 19-1

QAPP WORKSHEET #19 ANALYTICAL SOP REQUIREMENTS TABLES This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #19 Title: Site Specific QAPP for Source Area ST48 Analytical SOP Requirements Tables Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 19-2


QAPP Worksheet #20 Title: Site Specific QAPP for Source Area ST48 Field Quality Control Sample Summary Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 20-1

QAPP WORKSHEET #20 FIELD QUALITY CONTROL SAMPLE SUMMARY TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #20 Title: Site Specific QAPP for Source Area ST48 Field Quality Control Sample Summary Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 20-2


QAPP Worksheet #21 Title: Site Specific QAPP for Source Area ST48 Project Sampling SOP References Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 21-1

QAPP WORKSHEET #21 PROJECT SAMPLING SOP REFERENCES TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #21 Title: Site Specific QAPP for Source Area ST48 Project Sampling SOP References Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 21-2


QAPP Worksheet #22 Title: Site Specific QAPP for Source Area ST48 Field Equipment Calibration, Maintenance, Revision Number: 0 Testing, and Inspection Table Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #22 FIELD EQUIPMENT CALIBRATION, MAINTENANCE, TESTING, AND INSPECTION TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #22 Title: Site Specific QAPP for Source Area ST48 Field Equipment Calibration, Maintenance, Revision Number: 0 Testing, and Inspection Table Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #23 Title: Site Specific QAPP for Source Area ST48 Analytical SOP Reference Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #23 ANALYTICAL SOP REFERENCE TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #23 Title: Site Specific QAPP for Source Area ST48 Analytical SOP Reference Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 23-2


QAPP Worksheet #24 Title: Site Specific QAPP for Source Area ST48 Analytical Instrument Calibration Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 24-1

QAPP WORKSHEET #24 ANALYTICAL INSTRUMENT CALIBRATION TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #24 Title: Site Specific QAPP for Source Area ST48 Analytical Instrument Calibration Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #25 Title: Site Specific QAPP for Source Area ST48 Analytical Instrument and Equipment Maintenance, Revision Number: 0 Testing, and Inspection Table Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #25 ANALYTICAL INSTRUMENT AND EQUIPMENT MAINTENANCE, TESTING, AND INSPECTION TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #25 Title: Site Specific QAPP for Source Area ST48 Analytical Instrument and Equipment Maintenance, Revision Number: 0 Testing, and Inspection Table Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #26 Title: Site Specific QAPP for Source Area ST48 Sample Handling System Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #26 SAMPLE HANDLING SYSTEM SAMPLE COLLECTION, PACKAGING, AND SHIPMENT This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #26 Title: Site Specific QAPP for Source Area ST48 Sample Handling System Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #27 Title: Site Specific QAPP for Source Area ST48 Samples Custody Requirements Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #27 SAMPLE CUSTODY REQUIREMENTS This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #27 Title: Site Specific QAPP for Source Area ST48 Samples Custody Requirements Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #28 Title: Site Specific QAPP for Source Area ST48 QC Samples Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #28 QC SAMPLES TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #28 Title: Site Specific QAPP for Source Area ST48 QC Samples Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #29 Title: Site Specific QAPP for Source Area ST48 Project Documents and Records Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 29-1

QAPP WORKSHEET #29 PROJECT DOCUMENTS AND RECORDS TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #29 Title: Site Specific QAPP for Source Area ST48 Project Documents and Records Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #30 Title: Site Specific QAPP for Source Area ST48 Analytical Services Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #30 ANALYTICAL SERVICES TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #30 Title: Site Specific QAPP for Source Area ST48 Analytical Services Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #31 Title: Site Specific QAPP for Source Area ST48 Planned Project Assessment Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 31-1

QAPP WORKSHEET #31 PLANNED PROJECT ASSESSMENT TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #31 Title: Site Specific QAPP for Source Area ST48 Planned Project Assessment Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 31-2


QAPP Worksheet #32 Title: Site Specific QAPP for Source Area ST48 Assessment Findings and Corrective Response Actions Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 32-1

QAPP WORKSHEET #32 ASSESSMENT FINDINGS AND CORRECTIVE RESPONSE ACTIONS This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #32 Title: Site Specific QAPP for Source Area ST48 Assessment Findings and Corrective Response Actions Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 32-2


QAPP Worksheet #33 Title: Site Specific QAPP for Source Area ST48 QA Management Reports Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 33-1

QAPP WORKSHEET #33 QA MANAGEMENT REPORTS TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #33 Title: Site Specific QAPP for Source Area ST48 QA Management Reports Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #34 Title: Site Specific QAPP for Source Area ST48 Verification (Step I) Process Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 34-1

QAPP WORKSHEET #34 VERIFICATION (STEP I) PROCESS TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #34 Title: Site Specific QAPP for Source Area ST48 Verification (Step I) Process Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #35 Title: Site Specific QAPP for Source Area ST48 Validation (Steps IIa and IIb) Process Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP WORKSHEET #35 VALIDATION (STEPS IIA AND IIB) PROCESS TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #35 Title: Site Specific QAPP for Source Area ST48 Validation (Steps IIa and IIb) Process Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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QAPP Worksheet #36 Title: Site Specific QAPP for Source Area ST48 Validation (Steps IIa and IIb) Summary Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 36-1

QAPP WORKSHEET #36 VALIDATION (STEPS IIA AND IIB) SUMMARY TABLE This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #36 Title: Site Specific QAPP for Source Area ST48 Validation (Steps IIa and IIb) Summary Table Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 36-2


QAPP Worksheet #37 Title: Site Specific QAPP for Source Area ST48 Usability Assessment Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

Page 37-1

QAPP WORKSHEET #37 USABILITY ASSESSMENT This worksheet is included in the Installation-Wide Generic QAPP for Eielson AFB (USAF 2012).

QAPP Worksheet #37 Title: Site Specific QAPP for Source Area ST48 Usability Assessment Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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References Title: Site Specific QAPP for Source Area ST48 Revision Number: 0 Revision Date: February 2012 Contract No. FA8903-08-D-8791-0026

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REFERENCES

Alaska Department of Environmental Conservation (ADEC). 2008. Cleanup Levels 18 Alaska Administrative Code 75, Article 3. October.

ADEC. 2009a. Monitoring Well Guidance. February.

ADEC. 2009b. Draft Vapor Intrusion Guidelines for Contaminated Sites. July.

ADEC. 2010. Draft Field Sampling Guidance. May.

Air Force Center for Engineering and the Environment (AFCEE). 2006. AFCEE Guidance for Contract Deliverables, Appendix C: Quality Assurance Project Plan 2006.

Cheiron Resources, Ltd. 2008. Field Screening Text Instruction Manual.

Department of Defense (DoD). 2010. DoD Quality Systems Manual for Environmental Laboratories, Version 4.2, Based on NELAC Voted Revision, 5 June 2003. October.

United States Army Corps of Engineers (USACE). 1995. Final Report on Microwell Investigations of OU 1 & 2 at Eielson AFB, Alaska. April.

United States Air Force (USAF). 1989a. Installation Restoration Program Remedial Investigation/Feasibility Study Stage 3. April.

USAF. 1989b. Installation Restoration Program, Remedial Investigation/Feasibility Study Work Plan. May.

USAF. 1990. Installation Restoration Program Remedial Investigation/Feasibility Study Stage 4. May.

USAF. 1992a. Source Area 48 Power Plant Fuel Leak, Installation Restoration Program RI/FS, Final Report. February.

USAF. 1992b. Interim Record of Decisions for OU1B. September.

USAF. 1993a. Remedial Investigation/Feasibility Study, Operable Unit 1, Management Plan (Final). May.

USAF. 1993b. Final Remedial Design Operable Unit 1B Source Area, ST48. October.

USAF. 1993c. Site-Wide Groundwater Monitoring Program. 1993 Report. December.

USAF. 1994a. Eielson AFB OU1 ROD.


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USAF. 1994b. Remedial Investigation Report: OU1. February.

USAF. 1994c. OU1 Final Baseline Risk Assessment. May.

USAF. 1995a. Site-Wide Groundwater Monitoring Program 1994 Report. January. USAF. 1995b. Final Remedial Design, Operable Unit 1. November.

USAF. 1996. 1995 Sitewide Monitoring Program Report. May.

USAF. 1997a. 1996 Sitewide Monitoring Program Report. May.

USAF. 1997b. 1996 Final OU1 Pilot Study Monitoring Report. October.

USAF. 1998a. OU1 Remedial Action Summary Report. August.

USAF. 1998b. 1997 Sitewide Monitoring Program Report. August.

USAF. 1998c. First-Five Year ROD Review. September.

USAF. 1999a. 1998 Sitewide Monitoring Program Report. April.

USAF. 1999b. 1999 Sitewide Monitoring Program Report. December.

USAF. 2002a. 2001 Sitewide Monitoring Program Report. December.

USAF. 2002b. Draft Final RPO Phase II Technical Report. December.

USAF. 2003a. 2002 Sitewide Monitoring Program Report. June.

USAF. 2003b. Remedial Action Operation Report for Operable Units 1 and 2 (July 2002 – June 2003). Final. August.

USAF. 2004. Second Five-Year ROD Review. January.

USAF. 2007. 2006 Sitewide Monitoring Program Report. March.

USAF. 2008. Third Five-Year Review ROD Report. September.

USAF. 2012. Final Installation-Wide Generic Quality Assurance Project Plan, Eielson AFB. February.

United States Environmental Protection Agency (USEPA). 1989. Risk Assessment Guidance for Superfund, Vol.1, Human Health Evaluation Manual.

USEPA. 2001. EPA Requirements for Quality Assurance Project Plans EPA QA/R-5. March.


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USEPA. 2002. Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils. November.

USEPA. 2005. Intergovernmental Data Quality Task Force Uniform Federal policy for Quality Assurance Project Plans, Part I: UFP-QAPP Manual. March.

USEPA. 2006. Guidance on Systematic Planning Using the Data Quality Objectives Process. EPA QA/G-4.EPA/240/B-06/001. February.

USEPA. 2008. Contract Laboratory Program National Functional Guidelines for Superfund Organic Methods Data Review. EPA-540-R-08-01. June.

USEPA. 2010. Contract Laboratory Program National Functional Guidelines for Inorganic Superfund Data Review. OSWER 9240.1-51. EPA 540-R-10-011. January.

USEPA. 2011. Regional Screening Levels for Chemical Contaminants at Superfund Sites (http://www.epa.gov/reg3hwmd/risk/human/rb-concentration_table/index.htm). Accessed November 2011.

http://www.epa.gov/reg3hwmd/risk/human/rb-concentration_table/index.htm


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APPENDIX L DRAFT VAPOR INTRUSION GUIDANCE FOR CONTAMINATED SITES (2009)

1

DEPARTMENT OF

ENVIRONMENTAL CONSERVATION

Division of Spill Prevention and Response

Contaminated Sites Program

DRAFT VAPOR INTRUSION GUIDANCE FOR

CONTAMINATED SITES

July 2009

i

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i

TABLE OF CONTENTS

I. PURPOSE ....................................................................................................................................................................... 1

II. BACKGROUND ............................................................................................................................................................ 1

III. KEY RECOMMENDATIONS ..................................................................................................................................... 3

IV. VAPOR INTRUSION DECISION AND RESPONSE FRAMEWORK ................................................................... 4

STEP 1: CHECK FOR EXPLOSIVE OR SHORT-TERM EXPOSURE THREATS .................................................................................... 8 STEP 2: REFINE THE CSM FOR VAPOR INTRUSION .................................................................................................................... 9 STEP 3: CHARACTERIZE SITE AND REVIEW DATA QUALITY .................................................................................................... 10 STEP 4: COMPARE CONTAMINANT DATA TO TARGET LEVELS ................................................................................................. 11 STEP 5: DECIDE IF FURTHER EVALUATION IS NEEDED ............................................................................................................ 13 STEP 6: CHOOSE AN INVESTIGATIVE STRATEGY ...................................................................................................................... 14 STEP 7: SUBMIT WORKPLAN FOR DEC APPROVAL AND IMPLEMENT....................................................................................... 16 STEP 8: EVALUATE VAPOR INTRUSION POTENTIAL AND RISK TO RECEPTORS ......................................................................... 17 STEP 9: SUBMIT REPORT TO DEC WITH RECOMMENDATIONS FOR CLEANUP .......................................................................... 18 STEP 10: SUBMIT CLEANUP OR CORRECTIVE ACTION PLAN FOR DEC APPROVAL AND IMPLEMENT ....................................... 19 STEP 11: EVALUATE DATA TO CONFIRM CLEANUP OR MITIGATION EFFECTIVENESS FOR VAPOR INTRUSION ........................ 19 STEP 12: SUBMIT FINAL REPORT TO DEC ............................................................................................................................... 20

V. DATA COLLECTION AND INTERPRETATION ................................................................................................. 20

GROUNDWATER SAMPLING ..................................................................................................................................................... 20 Groundwater Sample Location .................................................................................................................................... 21 Monitoring Well Design and Groundwater Sampling Techniques ............................................................................... 21 Other Considerations for Collecting and Using Groundwater Data ........................................................................... 23

SOIL GAS SAMPLING ............................................................................................................................................................... 24 Soil Gas Sample Location, Depth, and Frequency ....................................................................................................... 25 Soil Gas Probe Installation and Sampling Techniques ................................................................................................ 25 Transient and Other Environmental Effects on Sampling ............................................................................................ 28

INDOOR AIR SAMPLING ........................................................................................................................................................... 28 Indoor Air Sample Location and Frequency ................................................................................................................ 29 Indoor Air Sampling Procedures ................................................................................................................................. 30 Considerations for Collecting and Using Indoor Air Data .......................................................................................... 31

ANALYTICAL METHODS AND SAMPLE HANDLING FOR SOIL GAS AND INDOOR AIR ................................................................ 31 Sample Containers ....................................................................................................................................................... 32 Sample Handling, Storage, and Transportation ........................................................................................................... 33 Analytical Methods and QA/QC ................................................................................................................................... 34

VI. INVESTIGATIVE STRATEGIES – SPECIAL CONSIDERATIONS .................................................................. 37

BACKGROUND AIR LEVELS ..................................................................................................................................................... 37 MULTIPLE LINES OF EVIDENCE ............................................................................................................................................... 38 PREDICTIVE MODELING ........................................................................................................................................................... 38 RISK ASSESSMENT ................................................................................................................................................................... 39 PETROLEUM BIODEGRADATION ............................................................................................................................................... 39

VII. MITIGATING A VAPOR INTRUSION PROBLEM .............................................................................................. 40

VIII. INSTITUTIONAL CONTROLS AT VAPOR INTRUSION SITES ................................................................... 4040

IX. RFERENCES ............................................................................................................................................................... 41

ii

TABLE OF FIGURES

Figure 1: General depiction of the vapor intrusion pathway in a residential setting. ................ 2 Figure 2: Steps in a vapor intrusion evaluation. ........................................................................ 5 Figure 3: Decision points in a vapor intrusion evaluation. ........................................................ 6

TABLE OF TABLES

Table 1: Guidance and publications on vapor intrusion. ........................................................... 3 Table 2: Advantages and disadvantages of various investigative strategies and sampling

approaches. ................................................................................................................ 15

Table 3: Monitoring well installation methods. ...................................................................... 22 Table 4: Groundwater sampling methods. ............................................................................... 22 Table 5: Summary of analytical methods for soil gas, indoor and ambient air samples. ........ 35

APPENDICES

Appendix A – Elements of the Vapor Intrusion Pathway (adapted from NJ DEP, 2005)

Appendix B – ATSDR Inhalation Minimal Risk Levels

Appendix C – Conceptual Site Model Checklist (from ITRC, 2007)

Appendix D – DEC Indoor Air Target Levels

Appendix E – DEC Shallow or Subslab Soil Gas Target Levels

Appendix F – DEC Deep Soil Gas Target Levels

Appendix G – DEC Groundwater Target Levels

Appendix H – Background Indoor Air Levels

Appendix I – DEC Building Survey and Indoor Air Sampling Questionnaire

iii

Acronyms

AKOSH – Alaska Occupational Safety and Health

ATSDR – Agency of Toxic Substance and Disease Registry

bgs – Below ground surface

BTEX – Benzene, toluene, ethylbenzene, and xylenes

CSM – Conceptual Site Model

CSP – Contaminated Sites Program

DEC – Department of Environmental Conservation

DQO – Data quality objective

EPRI – Electric Power Research Institute

MTBE – Methyl tert-butyl ether

NELAP – National Environmental Laboratory Accreditation Program

OSHA – Occupational Safety and Health Agency

PAH – Polycyclic aromatic hydrocarbon

PCB – Polychlorinated biphenyl

PEL – Permissible Exposure Limit

ppbv – Parts per billion by volume

ppmv – Parts per million by volume

QA/QC – Quality assurance/quality control

SVOC – Semi-volatile organic compound

TPH – Total petroleum hydrocarbon

µg/L – Micrograms per liter

µg/m3 – Micrograms per cubic meter

VOC – Volatile organic compound

iv

Alaska Department of Environmental Conservation

Vapor Intrusion Guidance Disclaimer:

Web links to the most current agency documents available are provided in the reference

section of this Guidance. Because this effort is continually evolving and adapting to meet

the needs of a broad environmental community, users of this document should verify they

have the most recent version of any referenced document.

1

I. PURPOSE

This document was prepared by the Alaska Department of Environmental Conservation

(DEC) to provide guidance for evaluating and responding to a vapor intrusion exposure

pathway at contaminated sites. When the conceptual site model (CSM) indicates that the

vapor intrusion pathway may be complete, a site-specific analysis is necessary per Title

18 of the Alaska Administrative Code [18 AAC 75.340 (i)]. Currently the method two

soil cleanup levels in Tables B1 and B2 of 18 AAC 75.340 address volatilization to

outdoor air and subsequent inhalation by receptors, but do not address vapor intrusion

into buildings where receptors exposed to indoor air may be affected. When vapor

intrusion is occurring, site-specific soil and groundwater cleanup levels may need to be

established. This guidance pertains to evaluating and controlling vapors migrating from

the subsurface into an occupied structure–DEC does not regulate indoor air. This

distinction is critical when determining cleanup goals for a site.

The strategy presented in this guidance is a series of steps for consistently assessing the

potential for risk from vapor intrusion. The need for a thorough assessment may be

identified at sites that are already in the cleanup process. Consequently, this guidance has

been designed to allow the user to begin evaluating vapor intrusion at any point in the

cleanup process. For a quick overview of DEC’s recommendations regarding this

pathway, see Section III.

II. BACKGROUND

Vapor intrusion is the migration of volatile chemicals from a subsurface vapor source

into overlying buildings. Before beginning an evaluation of the vapor intrusion pathway,

it is important to understand how vapors migrate and intrude into overlying buildings.

The process is similar to that of radon gas seeping into homes. This section briefly

describes a general conceptual model for vapor intrusion, as shown in Figure 1. A more

detailed description is provided in Appendix A.

Vapor intrusion begins with a vapor source. Contaminants volatilize from the vapor

source and move into the surrounding soil pore spaces as soil gas. Vapor sources may

include contaminated soil in the vadose zone, free-phase or residual non-aqueous phase

liquid (NAPL) above or near the top of the saturated zone, or shallow dissolved-phase

contamination in groundwater. Underground tanks and piping that contain volatile

chemicals can also release vapor clouds into the surrounding soil.

Vapors in the subsurface diffuse from areas of high concentration to areas of low

concentration. When vapors reach a building, advective forces associated with the

building may cause the vapors to flow through cracks in the foundation. In this document,

a foundation is defined as the lowest level of a building in contact with the soil, such as a

basement, crawl space, or slab-on-grade foundation. A building on posts, where airflow

beneath the building is not blocked by screening or other material, does not need to be

evaluated for vapor intrusion.

2

The rate of vapor migration through soil and into a building is difficult to quantify and

depends on soil types, chemical properties, building design and condition, and pressure

differentials between the subsurface and the building. An investigator should be aware

that climatic conditions, such as changes in barometric pressure or air temperature, wind,

and rainfall also can affect the degree to which vapor intrusion is occurring.

Figure 1: General depiction of the vapor intrusion pathway in a residential setting

(from EPA, 2002).

In extreme cases, vapors may accumulate in dwellings or occupied buildings to levels

that could cause explosions, acute health effects, or odors. In these cases, it is relatively

easy to determine that the vapor intrusion pathway is complete and that prompt

remediation or mitigation efforts are necessary. Typically, however, the chemical

concentrations are low and the main concern is that the contamination may pose an

unacceptable exposure risk from long-term indoor inhalation. At these sites, determining

whether the pathway is complete or not can be complicated. The presence of background

contaminants in households or commercial buildings (i.e., in the ambient air or emission

sources such as household solvents, gasoline, or cleaners) can make it difficult to

interpret direct measurements. Moreover, many soil and building characteristics can have

a dramatic impact on the potential for vapor intrusion.

In developing this guidance, DEC evaluated guidance from the U.S. Environmental

Protection Agency (EPA) and the Interstate Technology and Regulatory Council (ITRC),

as well as other states and organizations that are addressing the vapor intrusion pathway.

Useful references for evaluating the vapor intrusion pathway are listed in Table 1.

3

Table 1: Guidance and publications on vapor intrusion.

Primary Topic Document and Web Site Location*

General

Guidance

ITRC Vapor Intrusion Pathway: A Practical Guide (ITRC, 2007).

http://www.itrcweb.org/Documents/VI-1.pdf

EPA Draft Vapor Intrusion Guidance (EPA, 2002).

http://epa.gov/osw/hazard/correctiveaction/eis/vapor.htm

Guidance for Evaluating Soil Vapor Intrusion in the State of New York (NY

DOH, 2006).

http://www.health.state.ny.us/environmental/investigations/soil_gas/svi_guida

nce/

New Jersey Vapor Intrusion Guidance (NJ DEP, 2005).

http://www.nj.gov/dep/srp/guidance/vaporintrusion/vig.htm

Petroleum

Investigation

A Practical Strategy for Assessing the Subsurface Vapor-to-Indoor Air

Migration Pathway at Petroleum Hydrocarbon Sites (API, 2005).

http://www.api.org/ehs/groundwater/lnapl/soilgas.cfm

Property

Transactions

ASTM E2600-08 Standard Practice for Assessment of Vapor Intrusion into

Structures on Property Involved in Real Estate Transactions (ASTM, 2008).

For purchase at http://www.astm.org/Standards/E2600.htm

Soil Gas

Sampling

County of San Diego, Site Assessment and Mitigation Manual (SDC, 2009)

http://www.co.san-diego.ca.us/deh/water/sam_manual.html

California: Advisory – Active Soil Gas Investigations (DTSC, 2003)

http://www.dtsc.ca.gov/lawsregspolicies/policies/SiteCleanup/upload/SMBR_

ADV_activesoilgasinvst.pdf

Air Sampling Massachusetts Indoor Air Sampling and Evaluation Guide (MA DEP, 2002).

http://www.mass.gov/dep/cleanup/laws/02-430.pdf

Subslab

Sampling

An Assessment of Vapor Intrusion in Homes near the Raymark Superfund Site

using Basement and Subslab Air Samples (EPA, 2006).

http://www.dec.state.ak.us/spar/csp/guidance/raymark6report.pdf

Reference Handbook for Site-Specific Assessment of Subsurface Vapor

Intrusion to Indoor Air (EPRI, 2005). http://my.epri.com/

*We cannot guarantee all links provided are current.

III. KEY RECOMMENDATIONS

Some key recommendations for evaluating vapor intrusion in Alaska are outlined below.

Use a phased approach to evaluate the vapor intrusion pathway. Decisions about

pathway completeness and human exposure should not be based on one piece of

information, but a combination of factors. Before sampling, develop a CSM and use

all available data to evaluate the likelihood of vapor intrusion. If little is known about

the site, DEC recommends collecting exterior samples before collecting interior

samples. Exterior samples may allow the investigator to rule out vapor intrusion

without entering any buildings.

When the potential for vapor intrusion is high, collect indoor air and subslab or

near-slab soil gas samples, and consider mitigation. Indoor air samples provide

direct evidence about the indoor inhalation risk. Subslab or near-slab soil gas samples

provide evidence that the contamination is from the subsurface, not background

indoor or outdoor sources. In some cases, taking immediate measures to mitigate the



http://www.health.state.ny.us/environmental/investigations/soil_gas/svi_guidance/




http://www.astm.org/Standards/E2600.htm


http://www.dtsc.ca.gov/lawsregspolicies/policies/SiteCleanup/upload/SMBR_ADV_activesoilgasinvst.pdf




http://my.epri.com/

4

indoor air exposure may be appropriate. Sampling and cleanup plans must be

approved by DEC.

Remember contaminants in the vapor phase move differently than contaminants

in groundwater. Vapors in soil generally move away from a source by diffusion and

can travel in a direction opposite of the groundwater flow. When vapors are near a

building, advective forces associated with the building may cause vapors to move

toward the foundation.

Sample the appropriate media and location to meet the objective. The primary

objective of a vapor intrusion investigation is to determine if vapors are entering a

building from a subsurface contaminant source at a concentration that represents a

risk to the building occupants. If the source is in the vadose zone, groundwater

samples alone will not achieve this objective. If product or contaminated groundwater

is in contact with the building foundation, soil gas samples may also not achieve this

objective.

Do not use soil data for comparison to target levels, modeling vapor transport,

or in a risk assessment. Analytical soil data are poor quantitative predictors of

contaminant vapor concentrations in the subsurface. Soil data are acceptable for

qualitative evaluation of this pathway, but should not be used for numerical modeling.

However, DEC will consider the vapor intrusion pathway incomplete when the most

conservative Method 2 soil cleanup levels and groundwater cleanup levels are met

throughout the site.

Consider the potential for biodegradation of petroleum compounds under

specific site conditions. Petroleum vapors attenuate more rapidly in the soil pore

spaces than do more persistent volatile compounds, such as chlorinated solvents.

Typically, a low to moderate strength petroleum source will not result in vapor

intrusion if two feet of clean (uncontaminated) fine-grained soil or 5 feet of clean

coarse-grained soil containing at least 3 percent oxygen overlies the source. DEC will

not require further evaluation of the pathway when the investigator demonstrates

conditions sufficient for biodegradation.

IV. VAPOR INTRUSION DECISION AND RESPONSE

FRAMEWORK

DEC has identified 12 steps for addressing the vapor intrusion pathway. How these steps

ideally fit into the DEC Contaminated Sites (18 AAC 75) or Leaking Underground

Storage Tank (18 AAC 78) cleanup process is shown in Figure 2. Key decision points

within these steps are shown in Figure 3. Vapor intrusion is an emerging issue, thus

investigation and cleanup activities may be at various stages when vapor intrusion is first

considered. At historical sites, the first consideration of vapor intrusion may be after

significant site characterization and cleanup has already occurred, or even during the site

closure evaluation. If this is the case, the initial evaluation (Steps 2 through 5) becomes

very important, and may be part of the closure determination for the site. Regardless of

the starting point, the basic steps and concepts of a vapor intrusion evaluation are the

same for all sites.

Use the following steps whenever site information indicates that volatile and toxic

compounds are present and occupied buildings are or may be present in the future. DEC’s

5

Figure 2: Steps in a vapor intrusion evaluation.

DEC Cleanup Process DEC Vapor Intrusion Steps

INITIAL RESPONSE 18 AAC 75.315/ 18 AAC 78.220 INTERIM REMOVAL 18 AAC 75.330/ 18 AAC 78.30

FINAL REPORT 18 AAC 75.380/ 18 AAC 78.276

STEP 11: Evaluate effectiveness of cleanup effectiveness for vapor intrusion.

STEP 12: Submit final report for DEC approval.

STEP 1: Check for explosive or short-term exposure threats.

Repeat Step 1 when any new information becomes available.

Consider moving to step 10 when the potential for vapor intrusion remains high.

CLEANUP 18 AAC 75.360 Corrective Action 18 AAC 78.250-270

STEP 10: Submit cleanup or corrective action plan for DEC approval and implement.

SITE CHARACTERIZATION 18 AAC 75.335 Release Investigation 18 AAC 78.235

STEP 2: Refine the CSM for vapor intrusion.

STEP 3: Characterize site and review data quality.

STEP 4: Compare contaminant data to target levels.

STEP 5: Decide if further evaluation is needed.

Consider moving to step 10 if the potential for vapor intrusion is high.

If no further evaluation is needed, proceed to Step 9.

STEP 6: Choose an investigative strategy.

STEP 7: Submit workplan for DEC approval and implement.

STEP 8: Evaluate vapor intrusion potential and risk to receptors.

STEP 9: Submit report to DEC with cleanup recommendations..

6

Figure 3: Decision points in a vapor intrusion evaluation.

Are immediate or

short-term effects a

concern?

(Step 1)

Notify

approporiate

agency

YES

Do available data

adequately represent

contaminant vapors in a

building or in the

subsurface, between the

source and the foundation?

(Steps 2-3)

NO

Do groundwater, soil

gas, or indoor air data

exceed target levels?

(Step 4)

YES

Submit report

DEC approval.

(Step 9)

YES

Does other information

suggest further

evaluation is not

needed?

(Step 5)

NO

YESNO

Investigate vapor

intrusion

(Steps 6-8)

Go to Next Page

Are site conditions

present that preclude

screening?

(Step 3)

NO

YES

Investigate vapor intrusion

using indoor air and

subslab sampling

techniques.

(Steps 6-8)

Go to Next Page

Do indoor air data

exceed 1/10 the indoor

air target level?

NO

Collect additional

indoor air data to

evaluate

temporal trends.

YES

Are conditions that

support

biodegradation

present for petroleum

vapors?

(Step 3)

NO

YES

Submit report for

DEC approval.

(Step 9)

Investigate vapor

intrusion

(Steps 6-8)

Go to Next Page

NO

7

Figure 3, continued: Decision points in a vapor intrusion evaluation.

Investigate vapor intrusion

(Steps 6-8)

Submit report to DEC for approval; determine if

institutional controls are necessary.(Step 12)

YES

NO

NO

Cleanup soil or groundwater, and

mitigate vapor intrusion risk.

(Step 9-11)

NO

YES

Submit cleanup report to DEC for approval; determine if institutional controls are

necessary.(Step 12)

YES

Does vapor intrusion data indicate vapor

intrusion is occurring? (Step 8)

Do indoor air levels exceed DEC target

levels, or site-specific levels developed

through a risk assessment?

(Step 11)

Do indoor air data exceed DEC target

levels, or site-specific levels developed

through a risk assessment?

(Step 8)

8

Policy Guidance on Developing Conceptual Site Models (2005) provides more

clarification on these criteria. Alaska state regulations require that a qualified person

complete and report on the investigative and cleanup work described in this document.

Step 1: Check for Explosive or Short-Term Exposure Threats

In addition to long-term and chronic health risks, vapor intrusion can cause explosions

and acute health effects. Thus, the first step of the vapor intrusion assessment is to

determine if conditions represent an immediate or short-term threat to human health and

notify the appropriate agencies. This step should be considered as soon as there is

knowledge of a release and should be revisited any time new information becomes

available.

During an initial response, an investigator may use monitoring devices (e.g.,

photoionization detector or combustible gas indicator), interviews with building

occupants, and general knowledge of the site to evaluate whether contaminants could be

present indoors. DEC encourages the use of other screening methods to determine if high

levels of contaminants are present in indoor air; however, detection levels must be

carefully considered as many screening methods cannot detect indoor air contaminants at

levels that could cause health effects. Examples of screening methods that may be useful

during Step 1 include gas detector tubes and passive air samplers. Analytical indoor air

samples are usually not available during an initial response, but should be considered

when conditions suggest that vapors may be present (see Section V, “Indoor Air

Sampling”).

When evaluating immediate or short-term risks, take the following actions:

Notify DEC’s Prevention and Emergency Response Program (PERP) if a release

has just occurred or been discovered,

Notify the fire department immediately if explosive levels are present or

suspected.

Notify DEC’s Contaminated Sites Program (CSP) when odors, physiological

symptoms, or screening devices indicate vapors are present in buildings above

indoor air levels described in this guidance.

Notify Alaska Occupational Safety and Health (AKOSH) when indoor air

contaminants are present in a workplace above Permissible Exposure Limits

(PELs). PELs can be found at the following web link:

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDAR

DS&p_id=9992

When there is evidence that public health may be affected by vapor intrusion, the DEC

project manager will contact the State of Alaska Division of Public Health (DPH)

immediately and determine what steps should be taken. If indoor air or soil gas samples

are available, DPH will be notified under the following conditions:

Indoor air concentrations exceed Agency for Toxic Substances and Disease

Registry (ATSDR) inhalation minimal risk levels (Appendix B); or

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9992

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9992

9

Subslab or near-slab (see Section V, “Soil Gas Sampling”) soil gas concentrations

are more than 10 times the ATSDR inhalation levels (Appendix B) or 1,000 times

the DEC target indoor air levels (Appendix D).

If DPH concludes there is a public health threat from vapor intrusion, the investigator

should evaluate alternatives for addressing the risk as described in Step 9.

Step 2: Refine the CSM for Vapor Intrusion

The CSM is first developed during the initial stages of a contaminated site investigation

in accordance with the DEC’s CSM Guidance. The CSM will identify the vapor intrusion

pathway as complete when volatile and toxic compounds are suspected to be present near

an occupied building or where a building could be built in the future. The CSM Guidance

contains a list of volatile compounds and discusses when a building is close enough to

contamination to prompt additional evaluation (30 feet from a petroleum source and 100

feet from a non-petroleum source).

Once determined to be complete, the vapor intrusion pathway must be evaluated further

as described in this guidance. During this step, the investigator refines the CSM to better

describe vapor transport at the site and to prepare for the data quality review in Step 3. A

checklist to assist with refinement of the CSM is provided in Appendix C.

The investigator should consider the following precautions while developing the CSM.

Volatile compounds may naturally degrade into other volatile compounds that

need to be evaluated (e.g., trichloroethene can break down to vinyl chloride);

The distance that volatile compounds may migrate in soil, groundwater, or soil

gas is dependent on soil types, subsurface heterogeneity, length of time after

release, as well as the mass of contamination. Vapors migrate more easily through

dry, coarse-grained soil.

Preferential pathways, such as subsurface fractures, utility conduits, and drains or

sumps that open to the subsurface, may allow vapors to migrate more easily

toward or into a building and must be identified.

Caps around a building, such as an asphalt driveway or frozen ground, may

reduce volatilization to outdoor air and increase the concentration of contaminants

near the building foundation.

Buildings with tight construction, inadequate ventilation, or large stack effects are

more likely to induce vapor intrusion, particularly during winter months.

However, preliminary evidence from a few chlorinated solvent sites in Alaska

suggests vapor intrusion into some building may be the most pronounced in late

summer or fall. Thus, seasonal variation should be considered at all sites.

Vapor intrusion is less likely in buildings with a positive pressure ventilation

system, a subsurface depressurization system, or a sealed subsurface vapor

barrier. However, the potential for building systems to change or become less

effective in the future should also be considered.

Future use of a site may present more of a vapor intrusion risk than the current

use. The potential for construction near a vapor source should be considered.

10

Remodeling of existing buildings or changes in ventilation could also increase the

potential for vapor intrusion. A home that is refurbished to be more energy

efficient may also be more air-tight and thus more susceptible to vapor

accumulation.

Once all the site information has been evaluated and considered in the CSM, continue on

to Step 3.

Step 3: Characterize Site and Review Data Quality

During this step, the investigator compiles and evaluates existing analytical data for

screening against default target levels in Step 4. Often, site investigation begins before

vapor intrusion pathway is even considered and some analytical data may already exist to

compare with vapor intrusion target levels. Careful review of that data is necessary. The

most useful data for Step 4 include sample results from groundwater, soil gas, and indoor

air collected in or near occupied buildings. Soil data collection is useful for investigating

the nature and extent of contamination and evaluating the potential for vapor intrusion;

however, DEC has not calculated target levels for soil and soil data can only be used

qualitatively.

The quality and representativeness of the compiled data should be carefully considered

before making a decision regarding the vapor intrusion pathway. Investigators must

evaluate the data to determine whether:

All contaminants of concern (COCs) have been identified and investigated. Any

volatile compound that may be present at a site should be investigated as a COC,

including degradation products. Volatile compounds, including those that should

be investigated at petroleum release, are listed in Table B-1 of DEC’s CSM

Guidance.

Data have been collected following applicable DEC guidance; groundwater, soil

gas, and indoor air data must be collected following procedures and

considerations described in Section V.

The data are adequate for representing contaminant vapors, either in the building,

or in the subsurface between the source and the foundation. Data limitations,

including temporal and spatial considerations, are summarized in Section V and

must be carefully reviewed.

Laboratory analyses are of acceptable quality, as determined by DEC’s

Laboratory Data Review Checklist, available at

http://www.dec.state.ak.us/spar/guidance.htm#methods.

In many cases, useful quantitative data for screening vapor intrusion risk will not be

available at this step in the evaluation. If this is the case, consider collecting additional

site characterization data under a DEC-approved workplan using data collection methods

described in Section V.

The soil gas and groundwater target levels discussed in Step 4 may underestimate vapor

intrusion when certain site conditions are present (EPA, 2002). DEC recommends that

http://www.dec.state.ak.us/spar/guidance.htm#methods

11

Biodegradation at petroleum sites:

Petroleum vapors are known to

biodegrade easily in aerobic

conditions, but the target levels

discussed in Step 4 do not account for

biodegradation. If soil data or

knowledge of the site indicate clean,

oxygenated soil is present between the

source and the foundation, the

investigator should consider skipping

to Step 5 to evaluate the potential for

biodegradation. See Section VI,

“Petroleum Biodegradation” for more

information.

soil gas and groundwater data not be used for screening in Step 4 when the following

precluding conditions are present:

Do not use soil gas data for screening when NAPL is in contact with the building

foundation.

Do not use groundwater data for screening when groundwater contamination is

present within 5 feet of a foundation.

Do not use soil gas or groundwater data for screening when a vapor source is

present within 15 feet of a foundation, and one or more of the following exists:

o Buildings with significant openings to the subsurface (e.g., sumps,

unlined crawl spaces, earthen floors);

o Significant preferential pathways, either naturally occurring or

anthropogenic; or

o Buildings with very low air exchange rates (< 0.25 air exchanges/hour) or

very high sustained indoor/outdoor

pressure differentials (> 10 Pascals).

When precluding conditions are present, indoor air

samples may be the best option for evaluating exposure

within the building.

If the data are of sufficient quality, adequately represent

the vapor intrusion pathway, and no precluding conditions

prevent use of the available data, go to Step 4. Otherwise,

move to Step 6 to begin a vapor intrusion investigation, or

consider mitigation.

Step 4: Compare Contaminant Data to Target

Levels

The target levels are conservative, risk-based screening levels that have been developed

by DEC using chemical-specific parameters in DEC’s Cleanup Level Guidance (2008).

Indoor air target levels are calculated according to methods described by EPA (EPA,

2008) and are based on a cancer risk of 10-5

and a hazard quotient of 1. Soil gas and

groundwater screening levels are calculated by applying an attenuation factor to the

indoor air target levels and estimating soil gas partitioning from the groundwater using

Henry’s Law Constant (EPA, 2002). DEC is currently using the following conservative

attenuation factors in this calculation:

Shallow soil gas – attenuation factor of 0.1

Deep soil gas – attenuation factor of 0.01

Groundwater – attenuation factor of 0.001

DEC has not calculated target levels for analytical soil data because of the uncertainty in

using these data to estimate soil gas partitioning. Soil data can be used qualitatively to

determine if and where a vapor source is present, but cannot be used quantitatively to

screen out the pathway. As a rule of thumb, if cleanup has removed COCs in soil down to

12

Occupational standards: In scenarios where

significant background vapor sources are present

because of commercial or industrial use, the U.S.

Occupational Safety and Health Administration

(OSHA) standards and requirements may be

applicable. AKOSH has adopted OSHA

regulations for worker exposure to volatile

chemicals in industrial work places. In these

cases, DEC will generally defer to the OSHA

PELs in occupational settings if the COCs for

vapor intrusion are the same as job-related

chemical exposures regulated by OSHA.

Although DEC may accept OSHA air standards

to evaluate contaminant levels in indoor air,

additional investigation may also be required. At

some locations, land use could change from

occupational to residential and vapor intrusion

should be evaluated to assess the future risk.

Temperature adjustment for

groundwater target levels:

Groundwater target levels are

calculated by applying the Henry’s

Law Constant to the concentration in

groundwater in order to estimate the

concentration in soil gas. DEC uses a

constant based on a temperature of

25ºC. The investigator may propose

alternative groundwater target levels

using a Henry’s Law Constant

adjusted for the groundwater

temperature documented at the site.

For assistance with this calculation see

http://www.epa.gov/athen.learn2mode

l/part-two/onsite/esthenry.html.

the most stringent cleanup levels in 18 AAC 75,

Table B1 and B2, for all volatile COCs, DEC will

not require further evaluation of vapor intrusion from

a soil source.

Target levels are available for both residential and

commercial/industrial properties and can be used for

volatile compounds sampled in the following media:

Indoor air, including crawl space air

(Appendix D)

Shallow or subslab soil gas collected 5 feet or

less from a foundation or from the ground

surface (Appendix E)

Deep soil gas collected more than 5 feet from

a foundation or from the ground surface (Appendix F)

Groundwater (Appendix G)

The investigator must consider the CSM and the location of the vapor source in relation

to the building when deciding which target levels to use. For example, when a vapor

source is located 5 feet beneath a foundation, soil gas data collected at 10 feet and

compared to deep soil gas target levels will not adequately represent vapors that could

migrate into the building. Similarly, groundwater data should not be compared to

groundwater target levels when the vapor source is NAPL or soil contamination is near

the building.

Use residential target levels when buildings are lived in or when land use is uncertain. It

is also DEC’s policy to evaluate day care centers and schools as a residential use because

of the sensitivity of the exposed

population (children).

Commercial/industrial levels can be used

when contamination is near buildings

occupied by workers that are present for

a standard work week (8-10 hours per

day, 5 days a week) or less. If individual

workers are present for more than a

standard work week, or if sensitive

receptors are present, DEC may require

use of the residential level or

development of a site-specific target

level.

If data exceed the target levels, go on to

Step 5. If the indoor air concentrations of

any COC exceeds one tenth of the indoor

air target level, DEC recommends at least

http://www.epa.gov/athen.learn2model/part-two/onsite/esthenry.html

http://www.epa.gov/athen.learn2model/part-two/onsite/esthenry.html

13

Institutional Controls: When DEC

decides that no further evaluation

is warranted, institutional

controls may be required to

ensure the vapor intrusion

pathway is considered if site

conditions (or building

conditions) change. Institutional

controls may be useful when

buildings are not present, but

could be built in the future. For

additional information on

institutional controls, see Section

VIII.

two rounds of sampling to investigate variability and seasonal trends before deciding if

further work is necessary.

When sample data meet the criteria identified in Step 3 and are below the DEC target

levels, no further evaluation of the vapor intrusion pathway is necessary and a report

should be submitted to DEC that documents the results of Steps 1 through 4. Step 9

discusses this report in more detail.

Step 5: Decide if Further Evaluation is Needed

The assessment of vapor intrusion can be a complex task. Whenever possible, decisions

regarding this pathway should be made through a weight-of-evidence approach instead of

a simple comparison to target levels. Exceeding a target level does not automatically

imply that receptors are at risk or the pathway is complete.

DEC may decide no further evaluation is necessary when the vapor source is small, or is

more than 20 feet beneath the foundation, and one

or more of the following factors are present:

The source contains only low concentrations

of volatile compounds (e.g., weathered

diesel);

Subsurface conditions limit vapor migration

from the source to the foundation (e.g., low-

permeability soils);

Subsurface conditions promote

biodegradation of a petroleum source. Clean,

oxygenated soil between the source and the

building foundation often promotes

biodegradation and provides an effective

barrier to vapor intrusion (see Section VI,

“Petroleum Biodegradation”);

Poor outdoor or indoor air quality from background sources that cannot be

controlled during sampling masks any potential contribution from vapor intrusion

(see Section VI, “Background Air Levels”);

Limited building occupancy or use, although institutional controls may need to be

considered for future buildings or building operation;

Building characteristics reduce or dilute vapor intrusion (e.g., vapor barriers and

ventilation systems). Again, institutional controls may be needed to maintain

these characteristics.

Predictive modeling may also be useful as additional evidence for supporting decisions at

this stage, but should be limited to peer-reviewed and publicly available models (see

Section VI, “Predictive Modeling”).

When site data exceed the vapor intrusion target levels and the investigator decides

further evaluation is necessary, go on to Step 6 to plan an investigation, or consider

14

Multiple Lines of Evidence Sampling:

Multiple lines of evidence is the most

comprehensive strategy to a vapor

intrusion evaluation when evidence

already exists suggesting that vapor

intrusion is occurring. By collecting a

combination of sample types, the

investigator will be able to evaluate

background chemical interferences,

estimate risk to receptors, directly

measure the vapor source strength in the

subsurface, and evaluate the vapor

intrusion potential for future receptors.

moving directly to mitigation or cleanup (Step 10). If the investigator determines no

further evaluation is needed, proceed to Step 9 and submit a report to DEC documenting

the available data and conclusions.

Step 6: Choose an Investigative Strategy

The investigative strategy must be chosen based on all available site data, a careful

review of the CSM, and professional judgment. When choosing an investigative strategy,

the investigator should work closely with the DEC project manager. An investigation

often occurs in phases and the strategic approach may change as more information

becomes available. Initially, the investigation should focus on occupied buildings that

represent worst-case scenarios, such as residences, buildings closest to the source, or

those most susceptible to vapor intrusion.

Three basic strategies can be used during an investigation:

Exterior sampling – Soil gas or groundwater samples are collected outside the

building.

Interior sampling – Indoor air samples are collected inside the building or soil gas

samples are collected directly beneath the building foundation (subslab).

Multiple lines of evidence – Samples are collected concurrently from indoor air,

outdoor air, and subslab or near-slab (within 10 feet of the building) soil gas.

Different sampling approaches can be used within each strategy. Each sampling approach

has different advantages and disadvantages, as summarized in Table 2 and described

further in Section V. The investigative strategy is best decided on a site-specific basis in

consultation with the DEC project manager.

Generally, DEC recommends starting with exterior samples when the vapor source is

located away from the building or the location is not known. If soil gas and groundwater

data exceed target levels within 10 feet of the building or if other information is available

that suggests the vapor intrusion potential is high, indoor air samples should be collected

to determine if exposure is occurring above risk-based levels.

When collecting indoor air samples, DEC

recommends simultaneously collecting outdoor

air and subslab or near-slab soil gas samples.

This strategy, commonly known as “multiple

lines of evidence”, has been used successfully in

Alaska, particularly where chlorinated solvents

were spilled near a building. Additional

information about this strategy is provided in

Section VI, “Multiple Lines of Evidence”.If

vapor migration along preferential pathways is

suspected, soil gas samples may not adequately

represent vapor migration to indoor air.

15

Table 2: Advantages and disadvantages of various investigative strategies and sampling approaches.

Sampling

Approach

Useful

References Advantages Disadvantages

EXTERIOR INVESTIGATIONS

Groundwater

ITRC, 2007

(Section D-2)

Monitoring wells often already present.

Minimal variability.

Monitoring wells may not be constructed correctly or close

enough to a building.

Groundwater target levels are conservative and may

overestimate risk.

Active Soil Gas

ITRC, 2007

(Section D-4)

API, 2005

DTSC, 2003

Direct measure of vapors in the soil.

Minimal variability expected in deep soil gas samples.

Vertical or horizontal transects can be used to locate

source areas or evaluate vapor attenuation.

Variability may be a problem in shallow soil gas or samples

collected near the foundation.

Air leakage from the surface is possible in shallow soil gas

samples.

Soil gas target levels are conservative and may overestimate

risk.

Passive Soil Gas

ITRC, 2007

(Section D-5) Simple method to investigate contaminant source

areas and vapor migration pathways.

Not suitable as the only investigative method because results

are provided in units of mass instead of concentration.

Utility vapor

screening

Contact

Utility Important when a utility corridor may be a preferential

pathway into a building.

Screening in or around utilities can be a dangerous activity and

must be coordinated with the utility.

INTERIOR INVESTIGATIONS

Subslab

Soil Gas

ITRC, 2007

(Section D-6)

API, 2005

EPA, 2006

Best measure of vapors that may be entering a

building.

Can assist with data interpretation when background

sources are present.

Cost is comparable or cheaper than exterior soil gas

sampling.

In some cases, volatile compounds from background sources

can migrate beneath the slab.

Requires building access and permission to drill through slab.

Variability may be a problem.

Crawl Space ITRC, 2007

(Section D-9) Can be used as an alternative to subslab sampling

when no slab is present.

Results need to be evaluated as indoor air unless attenuation

between the crawl space and the living space are demonstrated.

Background sources could affect crawl space air.

Indoor Air ITRC, 2007

(Section D-8) Direct measure of the risk to building occupants.

Identifies immediate health concerns.

Data interpretations can be complicated by background

chemical concentrations.

Significant temporal and spatial variability possible.

Future vapor intrusion potential can be difficult to assess with

indoor air data.

MULTIPLE LINES OF EVIDENCE INVESTIGATIONS

Indoor, Outdoor,

and Subslab or

Near-slab Soil Gas

ITRC, 2007

(Section D-6)

EPA, 2006

EPRI, 2005

This strategy is particularly useful when background

sources are present.

Requires more intensive sampling.

16

Other investigative techniques, including utility vapor screening or indoor air

measurements, may provide better data for evaluating the pathway.

The potential for biodegradation at petroleum sites can be assessed by analyzing soil gas

samples for fixed gasses (O2, CO2, and CH4) between the source and the building

foundation. This will allow an evaluation of biodegradation potential and attenuation

rates at petroleum sites, as described in Section VI, “Petroleum Biodegradation”.

Once an investigative strategy has been chosen, proceed to Step 7.

Step 7: Submit Workplan for DEC Approval and Implement

A vapor intrusion workplan may not be the first workplan developed for the site.

Typically, a site characterization or release investigation will be underway and the

investigator will have a basic understanding of the nature and extent of contamination.

Depending on the overall site goals at the time the vapor intrusion pathway is identified,

the investigator may choose to develop the vapor intrusion workplan alone, or as part of a

site characterization workplan.

When developing the workplan, the following elements should be included:

Discussion of CSM – Describe refinements to the CSM in Step 2.

Discussion of data gaps – Demonstrate that the investigative strategy is designed

to fill data gaps identified in Step 3.

Locations to be investigated – Identify which properties or buildings require

investigation. A phased approach, starting with the buildings closest to the source

and expanding radially, is acceptable when multiple buildings are a concern.

Specific criteria should be established to determine when and where to extend the

investigation to other buildings.

Building Inventory and Indoor Air Sampling Questionnaire – Complete Part 1 of

DEC’s questionnaire (Appendix I) for each building under investigation. The

questionnaire will help the investigator identify building characteristics and

possible vapor-entry points that will influence the vapor intrusion pathway. Be

sure to identify any utilities that should be avoided during subslab drilling

activities.

Building walkthrough – If the workplan includes indoor air sampling, plan to

conduct a building walkthrough at least 24 hours before collecting the samples.

During the walkthrough, possible sources of background contaminants should be

removed. Part 2 of DEC’s questionnaire (Appendix I) includes a building

walkthrough form that can be completed at this time.

Sampling and analysis plan – Describe the methods for collecting and analyzing

soil gas, indoor air, outdoor (background) air, or groundwater samples.

Field schedule – Provide proposed dates for field work. Inform the DEC project

manager of any changes to the schedule. DEC may conduct random field

inspections during vapor intrusion investigations.

17

Community Outreach:

Community outreach should be part of the vapor intrusion assessment process

to facilitate workplan implementation and for open communication between

DEC and the affected building occupants. Potentially affected building

occupants should be informed early in the process when a vapor intrusion

investigation is planned.

DEC has developed general vapor intrusion fact sheets for the public, located

at http://www.dec.state.ak.us/spar/csp/vi.htm. Investigators also may need to

develop site-specific fact sheets. DEC’s vapor intrusion workgroup staff and

DEC’s public outreach staff are available for guidance when a significant

concern about indoor air quality arises, especially when multiple properties are

involved.

DEC approval must be obtained before implementing the workplan. When interior

samples will be collected, workplans must be coordinated with building owners and

occupants. Sampling dates and times may need to be chosen that minimize the

potential for background interference from chemical usage in the building. Soil gas

and indoor air sampling may be affected by inclement weather; therefore, workplan

implementation should accommodate potential schedule delays.

Step 8: Evaluate Vapor Intrusion Potential and Risk to Receptors

The objectives of a vapor intrusion investigation are two-fold: 1) determine if vapor

intrusion into a building is occurring, and 2) determine if interior vapor concentrations

resulting from vapor intrusion pose a risk to the occupants or future occupants. Once

vapor intrusion data have been collected, the investigator must interpret the results to

address the objectives above.

Data collected in a vapor intrusion investigation should first be reviewed to determine the

potential for short-term exposure of building occupants, as described in Step 1. If short-

term exposures are documented, the procedures identified in Step 1 should be followed.

Steps 2 and 3 also should be revisited to determine if the CSM should be revised, data

quality is acceptable, and how contaminant levels compare to target levels. If data gaps at

this stage prevent achievement of the investigative objectives, the investigator should

propose additional sampling or evaluation. DEC may require submittal of another

workplan (Step 7).

The initial data interpretation usually includes comparing them to the target levels, as

described in Step 4. If the concentrations exceed target levels, the risk at the site can be

further evaluated through more advanced methods, including site-specific risk

assessment, predictive modeling, and measuring biodegradation parameters. These

techniques are discussed further in Section VI.

http://www.dec.state.ak.us/spar/csp/vi.htm

18

Sufficient investigation has been completed when the investigator can address the

objectives described above. At this point, the investigator summarizes the data and their

interpretation of the data in a vapor intrusion report as described in Step 9.

Step 9: Submit Report to DEC with Recommendations for Cleanup

In this last step of the vapor intrusion evaluation before the cleanup phase begins, the

investigative results, data evaluation, and recommendations should be documented in a

report and submitted to DEC. This report will often be included in a more general site

characterization or release investigation report, but could be submitted separately. The

report must be prepared by a qualified person and should address the following:

Describe activities completed in accordance with the vapor intrusion investigation

workplan.

Summarize the sampling and analysis results.

Demonstrate that the data adequately characterizes the extent of vapors that may

enter a current or future building.

Propose cleanup alternatives for the site that address the vapor intrusion risk.

Vapor intrusion may not be the only pathway of concern at a site. The cleanup approach

should must account for all applicable pathways and comply with all regulations. Along

with the proposed cleanup alternatives, the investigator should provide an analysis of

each alternative based on the following five criteria:

Protectiveness – How well does each alternative protect human health, safety,

welfare or the environment, both during and after the cleanup action?

Practicable – Are the technologies/techniques under consideration capable of

being designed, constructed, and implemented in a reliable and cost-effective

manner? What alternatives are the most cost effective?

Short- and Long-term Effectiveness – Are there potential adverse effects to

human health, safety and welfare, or the environment during construction or

implementation of the alternative? How fast does the alternative reach cleanup

goals? How well does the alternative protect human health, safety, and welfare or

the environment after completion of the cleanup? What, if any, risks will remain

at the site?

Regulations – Will the alternative comply with all state and federal regulations?

Public Input – Have comments received from the community regarding each

alternative been considered and addressed?

For more information on conducting a cleanup alternatives analysis, refer to EPA’s

March 1990 Fact Sheet entitled “The Feasibility Study: Detailed Analysis of Remedial

Action Alternatives”, which can be found at

http://www.epa.gov/superfund/policy/remedy/pdfs/93-55301fs4-s.pdf. The complexity of

the alternatives analysis should be scaled to the specific site.

http://www.epa.gov/superfund/policy/remedy/pdfs/93-55301fs4-s.pdf

19

If cleanup is not warranted, submittal of the vapor intrusion report will be the final step of

the vapor intrusion evaluation. If further work is required, proceed to Step 10 to develop

the cleanup plan.

Step 10: Submit Cleanup or Corrective Action Plan for DEC Approval and

Implement

If the investigator determines site conditions pose a current or future indoor inhalation

risk during Step 8, DEC will require that the risk be reduced through a cleanup or

corrective action, if feasible. Cleanup typically includes soil or groundwater remediation

to remove the source of the contaminant vapors and is DEC’s preferred method for

addressing the risks from contamination. However, soil and groundwater cleanup may

not be an effective approach for addressing a current exposure to vapors. In these cases,

mitigation strategies may be needed by themselves or in concert with cleanup to

temporarily control the risk until the contamination naturally degrades or the site

conditions change. Mitigation includes systems or controls associated with a building that

treat contaminants in indoor air (e.g. filtering systems) or prevent vapors from entering a

building (e.g. heating and ventilation systems that create a positive pressure in the

building, depressurization systems that create a negative pressure beneath the building

foundation).

Once a cleanup alternative is chosen, as described in Step 9, a cleanup or corrective

action plan should be prepared that includes, at a minimum, the following elements:

The selected cleanup alternative and the rationale for selection.

An exit strategy that describes the criteria for ceasing the cleanup or mitigation

efforts.

A sampling and analysis plan to determine the effectiveness of the cleanup or the

mitigation and satisfy the needs of the exit strategy.

A description of how institutional controls, if needed, will be established to ensure

remedial effectiveness.

A schedule for implementation and monitoring.

Detailed specifications for any soil or groundwater cleanup technique that is

proposed.

Other applicable requirements of 18 AAC 75.360 for the selected strategy.

The cleanup plan must be submitted to DEC for approval before implementing the

cleanup. On small sites or sites with a simple cleanup strategy, the cleanup plan can be

included in the vapor intrusion report to expedite the process. Further information and

helpful resources for installing mitigation systems in Alaska are discussed in Section VII.

Institutional controls are discussed in Section VIII.

Step 11: Evaluate Data to Confirm Cleanup or Mitigation Effectiveness for

Vapor Intrusion

After the cleanup plan has been implemented, buildings of concern should be evaluated

to determine if the cleanup was effective in reducing vapor intrusion. This evaluation will

20

usually be based on indoor air or soil gas monitoring and will be similar to the data

review processes described in Steps 4 and 8. The number of monitoring events and type

of sampling will be decided on a site-specific basis and should be described in the exit

strategy included in the cleanup plan. As with any sampling steps, it is important to

review the data quality and to consider how temporal and spatial variability may affect

the results. Soil gas monitoring or other types of confirmation samples may be sufficient

for some remedial approaches, such as excavation.

After a cleanup, 18 AAC 75.325(g) requires calculation of cumulative risk. Cumulative

risk calculations should be based on indoor air analytical results. If indoor air results are

not available or do not represent vapor intrusion contamination, cumulative risk

calculations for the vapor intrusion pathway may be based on subslab soil gas or near-

slab soil gas data. DEC will generally not require calculation of cumulative risk based on

exterior soil gas or groundwater data.

If data indicate that contaminant vapors in the subsurface or those migrating into indoor

air exceed the target levels after the cleanup, the cleanup plan may need to be revisited

and additional strategies considered. Once the cleanup is complete or enters into a long-

term monitoring phase, proceed to Step 12.

Step 12: Submit Final Report to DEC

Once vapor intrusion cleanup and mitigation actions have been completed and the

effectiveness of these actions evaluated, the qualified person should document these

activities and submit the results to DEC as part of the final site report. The report should

include a description of any institutional controls established at the site to prevent future

vapor intrusion or unacceptable risk from this pathway (see Section VIII). DEC may

require long-term monitoring to track effectiveness of mitigation systems or reporting to

track conditions that could affect decisions made about the site. If this is the case, a long-

term monitoring or reporting plan should be submitted with the final report.

DEC will review and comment on the report. If DEC approves the report, a closure

determination may be issued. However, this determination is rarely based on vapor

intrusion alone; therefore the site may remain open until other concerns not related to

vapor intrusion have been addressed.

V. DATA COLLECTION AND INTERPRETATION

This section will describe different sampling approaches, recommend sampling methods,

and discuss considerations that could affect data quality. Appendix D of the ITRC Vapor

Intrusion Guidance (2007) should be consulted for additional tools that may be useful in a

vapor intrusion investigation.

Groundwater Sampling

In general, DEC does not recommend installation of new monitoring wells for

investigating vapor intrusion because soil gas samples provide a more direct measure of

migrating vapors. When groundwater contamination is the primary source for vapor

21

intrusion, the investigator may use groundwater data to determine if further investigation

is needed. Groundwater data are useful because the groundwater concentration of a

particular compound multiplied by its Henry’s Law constant provides an estimate of the

soil gas concentration immediately above the groundwater interface. This calculation

assumes equilibrium partitioning across the groundwater interface; therefore,

groundwater samples most accurately represent concentrations of volatile compounds at

the groundwater interface. Monitoring well design and sampling techniques are important

considerations when collecting groundwater data for this purpose.

Important guidelines when evaluating groundwater data or collecting additional data

include the following:

If a source of vapors (e.g., NAPL, soil contamination) exists above the

groundwater surface near a structure, do not use groundwater data to rule out

vapor intrusion.

Collect groundwater samples from wells screened across the groundwater

interface at the time of sampling. Samples should represent contaminant

concentrations at the groundwater surface and must be collected from the upper 5

feet of the water column.

Minimize volatilization losses during sample collection. Spatial and temporal

seasonal variability of the groundwater contamination should be characterized.

Groundwater Sample Location

Before using groundwater data to rule out further evaluation of the vapor intrusion

pathway, groundwater contamination should be sufficiently characterized to estimate the

highest potential concentrations near any current or future building. For screening against

the target vapor intrusion levels, use groundwater data that is between the source and the

building, and as close to the building as possible. When groundwater contamination

extends beneath a building, the investigator should use groundwater data collected

immediately upgradient of the building. If these data are not available, surrounding data

points may be interpolated to construct contaminant isoconcentration maps.

Monitoring Well Design and Groundwater Sampling Techniques

Installation and sampling of groundwater monitoring wells shall follow procedures

described in DEC’s Monitoring Well Guidance (2009) and Underground Storage Tanks

Procedures Manual (2002), unless DEC approves an alternate technique such as

sampling with passive diffusion bags.

Groundwater samples can be collected from monitoring wells or direct-push probes, but

the screen length should be no greater than 10 feet. Shorter screen lengths are preferred

because less water from deeper in the aquifer enters the well and dilutes the sample.

Ideally, the thickness of the water column in the well should also be 10 feet or less. Some

advantages and disadvantages of different well installation techniques are described in

Table 3.

22

Table 3: Monitoring well installation methods.

Method Advantages Disadvantages

Direct-push

probes

Can do vertical profiling, discreet

interval sampling, and defined

depth intervals.

Rapid sampling at multiple

locations.

Not intended as a permanent well,

which is required for long-term

monitoring. (See DEC Monitoring

Well Guidance, 2008)

Some methods limited to

unconsolidated formations.

Monitoring

wells

Allows for long-term, repeat

sampling.

Suitable for a variety of sample

collection methods.

Screened interval can tolerate water

level fluctuations.

Installing new wells solely for

evaluating the vapor intrusion

pathway are not recommended.

Consider installing soil gas probes

instead.

Groundwater sampling methods that minimize the loss of volatile compounds during

sample collection and handling are necessary. DEC recommends the use of bladder

pumps and submersible pumps for low-flow purging and sampling. Other methods, such

as peristaltic pumps, passive diffusion-bag samplers, and Hydrasleeves®, may be useful,

as described in Table 4 below.

Table 4: Groundwater sampling methods.

Method Advantages Disadvantages

Bladder Pumps and

Submersible Pumps

Little disturbance of water

column if deployed carefully.

Pumps operate at a low flow

rate, minimizing volatile loss.

Pumps require power and

maintenance.

Pump must be dedicated or

cleaned between uses.

Peristaltic Pumps Little disturbance of water

column.

Pumps operate at low flow rate,

minimizing volatile loss.

Applies vacuum to water

sample which may affect gas

dissolution in the sample.

Should only be used for

sampling shallow groundwater

(less than 15 feet from the

ground surface).

Passive sampling

devices (passive

diffusion bags and

Hydrasleeves®)

Does not require purging

Minimize well disturbance and

loss of volatiles.

Easy to use for repeat

sampling.

Suitable for a variety of sample

collection methods.

Passive diffusion bags require

being left in the well for a

minimum of two weeks.

23

Monitoring wells should be purged using low-flow techniques to remove stagnant casing

water from the well. If evaluating vapor intrusion is the only sampling objective, DEC

recommends two modifications to the typical low-flow purging and sampling procedure:

Set the pump intake level as close to the groundwater surface as possible without

causing the water level to drop and expose the pump intake. For wells in

formations with average or high permeability, about 1.5 feet to 2 feet below the

static water level should be an adequate intake location.

The purging objective is to flush two casing volumes of groundwater through the

sampling array (tubing and pump, etc.). Drawdown should be measured and not exceed 0.3 feet.

Bailers are not recommended for sampling because the bailer agitates the water column

and collects a volume-averaged sample that may not represent the top of the water

column. If bailers are used, the reported data should be qualified as an underestimate.

Other Considerations for Collecting and Using Groundwater Data

Additional considerations for obtaining new groundwater data or evaluating old data for a

vapor intrusion evaluation are provided below:

Perched aquifers

Perched aquifers are zones of groundwater isolated from the regional aquifer by an

impermeable soil layer. If a perched aquifer exists above the regional aquifer, it may be

appropriate to collect samples from both the perched zone and regional shallow aquifer to

obtain a representative sample of all of the potential sources of vapors. The perched

aquifer, although not hydraulically connected, could be the largest source of vapors for an

overlying building and should be sampled if it is of sufficient thickness. A perched

saturated zone should be sampled if it is laterally contiguous under or near a building,

exists year-round, and is of sufficient thickness to obtain a sample.

Groundwater surface fluctuations

Groundwater can either expose (during dropping water table conditions) or submerge

(during rising water table conditions) areas of soil contamination. A dropping water table

may lead to greater volatilization. A rising water table can flush contamination from

newly-submerged soil and increase the size of the plume. The relationship between

groundwater fluctuations, contaminant sources, and vapor migration should be

considered when deciding if groundwater data are adequate to evaluate the potential for

vapor intrusion. DEC is researching the appropriate time(s) of year to collect these

samples in cold climates.

Clean water lens

A diving plume can form when changes in soil permeability result in a downward vertical

gradient, or when infiltration from the surface recharges groundwater over a plume. A

clean water lens will form over a diving plume that can prevent volatilization from the

contaminated groundwater and reduce vapor intrusion from a groundwater source.

Because diving plumes are not easy to recognize, but may affect how groundwater data

24

are interpreted, the investigator should be aware factors that may cause or reduce a clean

water lens.

Presence of NAPLs

Before sampling a monitoring well, the column of water in the well casing must be

checked for the presence of NAPLs, including free petroleum products that might be

floating on top of the water or in a separate layer at the bottom of the well casing. If

NAPL is present, a water sample should not be collected.

Drinking water wells

Groundwater samples used to evaluate vapor intrusion should not be collected from

drinking water wells. Drinking water wells are generally screened below the groundwater

surface.

Soil Gas Sampling

Soil gas can be collected using active or passive methods. Passive soil gas sampling

consists of burying an adsorbent media in the ground, which collects vapors over a given

time period through diffusion. Passive sampling provides qualitative data in units of

mass. This data is useful for locating a vapor source and characterizing the extent of

vapor migration, but cannot be used alone to evaluate risk.

Active soil gas sampling, which is discussed further in this section, consists of the

withdrawal of soil vapor from the subsurface through a sampling probe or tube into a gas-

tight container. This method provides quantitative data in units of concentration and is the

preferred contaminant data set for evaluating the potential for vapor intrusion to indoor

air.

Soil gas data are reflective of subsurface properties and allow for real-time results. Soil

gas data are recommended over other data for characterizing subsurface vapors and the

potential for vapor intrusion, because soil gas is a direct measure of the contaminant

concentration before it is diluted by ambient air. Drawbacks to this method include

potential spatial and temporal variability, inconsistent or poor sample collection

techniques, and indirect measurement of the actual risk to a receptor in the building.

Soil gas samples are collected from three primary locations. Soil gas samples collected 10

feet or more from the perimeter of the building are generally referred to as “exterior”

samples. “Near-slab” soil gas samples are collected outside a structure but within a short

distance (usually 10 feet) of the building’s foundation. Finally, “subslab” soil gas samples

are collected from below the building foundation or slab. The collection techniques for

near-slab and exterior samples are similar, while the collection of subslab samples has

special considerations which will be discussed in the following sections.

Important guidelines when collecting or evaluating soil gas data include the following:

Collect exterior soil gas samples from depths greater than 18 inches below ground

surface to avoid dilution of samples with ambient air.

25

Include leak detection when installing soil gas probes at depths less than 10 feet

below ground surface or subslab.

Install surface seals in all soil gas probes using grout or other approved materials.

Minimize purge volumes and sample flow rates during sampling.

Do not chill soil gas samples during transport.

Soil Gas Sample Location, Depth, and Frequency

When deciding on soil gas sample locations, the investigator should consider the location

of releases, other potential vapor sources, preferential pathways (e.g., utilities or sumps

entering a building), and lithology. A sufficient number of samples should be collected to

represent the maximum vapor concentrations that could impact the current or future

occupied structures. At least three locations should be sampled per building with one in

the area of the highest soil or groundwater contamination near or beneath the building.

The sample depth should maximize the chances of detecting contamination, but minimize

the effects of changes in barometric pressure, temperature, or breakthrough of ambient air

from the surface. Exterior samples should be collected at a minimum depth of 18 inches

below surface. Subslab samples are intended to collect the soil gas directly beneath the

foundation and should not extend into the soil. Their depth is determined by the thickness

of the foundation. Multiple depths should be considered for exterior samples so

attenuation factors can be more accurately determined.

Site soil or lithologic information should also be used to select appropriate locations and

depths for soil gas probes. The most permeable zones around the building or proposed

building should be targeted for sampling even if they are not the closest. If the site

consists primarily of low permeability soils, other sampling techniques should be

considered, such as passive sampling or indoor air sampling. Excessive vacuum, such as

10 inches of mercury or more, may cause unrepresentative partitioning of the

contaminants into the vapor phase. Precautionary consideration should always be given to

ensuring that a contaminant pathway is not being created through a low permeability

zone.

Seasonal environmental conditions (e.g., changes in soil temperature, soil moisture, snow

cover, and frozen ground) and seasonal heating and ventilation of a building can affect

volatilization and migration of contaminants in soil gas. If a vapor intrusion potential

exists at a site, soil gas sampling should occur in at least two seasons to identify seasonal

trends. In some cases, DEC may require soil gas data from more than two seasons.

Soil Gas Probe Installation and Sampling Techniques

Drilling techniques for all soil gas samples, including subslab samples, should minimize

soil disturbance as much as possible during installation. The probe is allowed to

equilibrate after installation, and the sampling train must be purged before sampling.

Additional detail about these procedures is provided below.

26

Exterior and near-slab soil gas probe installation

DEC recommends using direct push drilling techniques for exterior soil gas sampling.

Other techniques, such as rotary drilling, typically have longer equilibration times, but

can be proposed in the workplan.

Temporary soil gas probes are installed by driving the probe rod to a predetermined depth

and then pulling it back to expose the inlets of the soil gas probe. After sample collection,

both the drive rod and tubing are removed. During sampling, hydrated bentonite or some

other surface seal should be used around the drive rod at ground surface to prevent

ambient air intrusion from occurring. The inner soil gas pathway from probe tip to the

surface should be continuously sealed (e.g., a sampling tube attached to a screw adapter

fitted with an o-ring and connected to the probe tip) to prevent infiltration.

Permanent or semi-permanent soil gas probes are usually installed when multiple

sampling events are planned. A sand pack should be placed around the sample probe and

at least one foot of bentonite grout should be applied above the sand pack. Probes should

be properly secured, capped, and completed to prevent infiltration of water or ambient air

into the subsurface and to prevent accidental damage or vandalism.

Subslab probe installation

A subslab probe is installed by drilling through the foundation with a hand-held drill.

Drilling should not extend into or disturb the soil. A typical subslab probe is constructed

from small-diameter (⅛- or ¼-inch outside diameter) stainless steel or another inert

material and stainless steel compression fittings. A surface seal should be installed

around the probe to prevent air leakage into the subslab environment. Subslab probes

must also be properly capped, sealed, and completed to prevent infiltration of water or

ambient air into the subsurface.

Equilibration time

During probe installation, subsurface conditions are disturbed. To allow for subsurface

conditions to equilibrate, the following equilibration times are recommended:

Probes installed with the direct push method, where the drive rod remains in the

ground, should not be used for at least 20 minutes following probe installation.

Probes installed with the direct push method, where the drive rod does not remain

in the ground, should not be used for at least 30 minutes following probe

installation.

Probes installed with hollow-stem drilling methods should not be used for at least

48 hours following probe installation.

Subslab probes do not disturb the subsurface soil and equilibration is not

necessary. However, subslab probes should not be used until the sealant around

the probe has cured, as determined by the manufacturer’s directions.

Purge volume

The sampling train must be purged before sample collection to ensure stagnant or

ambient air is removed from the sampling system. Purge volumes should be kept to a

minimum to decrease the chance of leaks, reduce additional partitioning of the

27

contaminant into the vapor phase, and unnecessary movement of the soil gas to the

sampling probe. DEC recommends using sampling trains that minimize the dead-space

and purging three to five volumes of the sampling train.

The dead space volume can be estimated by summing the internal volume of tubing used,

annular space around the probe tip, and, in some cases, the volume of the sample

container. Summa canisters, syringes, and Tedlar® bags are not included in the dead

space volume calculation.

Purge and sample flow rate

Sampling and purging flow rates should not enhance compound partitioning during soil

gas sampling. DEC recommends purging and sampling at rates between 100 to 200

milliliters per minute to limit stripping, prevent ambient air from diluting the soil gas

samples, and to reduce the variability of purging rates. This equates to collection of a 6-

liter summa canister over at least 30 minutes. The low-flow purge rate increases the

likelihood that representative samples may be collected. The purge/sample rate may be

modified based on conditions encountered in individual soil gas probes with DEC

approval; however, low flow rates are particularly important when soil gas samples are

being collected from a shallow depth.

Tubing

Sampling tubes should be of a small diameter (⅛ to ¼ inch) to prevent turbulent flow and

made of material, such as nylon, stainless steel, or Teflon®, that will not react or interact

with site contaminants. Clean, dry tubing should be used at all times. If moisture, water,

or an unknown material is present in the probe before insertion, the tubing should be

decontaminated or replaced.

Sample systems with vacuum pumps

Soil gas samples from collection systems that use vacuum pumps should be collected on

the intake side of the pump to prevent potential contamination from the pump. Also,

because the pressure on the intake side of the pump is less than atmospheric pressure, soil

gas samples must be collected with adequate collection devices, such as those with gas-

tight syringes and valves, to ensure that the samples are not diluted by outside air.

Leak test

Leakage during soil gas sampling may dilute samples with ambient air and produce

results that underestimate actual site concentrations or contaminate the sample with

external contaminants. Leak tests should be conducted at every soil gas probe, unless

otherwise approved by DEC, and at any location where ambient air could enter the

sampling system or where cross contamination may occur. During a leak test, tracer

compounds, such as helium, pentane, isopropanol, isobutene, propane, or butane, are

applied around the sampling train immediately before sampling. Leakage can be

considered present when the tracer compound is present in the test sample at more than

10 percent of the source concentration.

28

Transient and Other Environmental Effects on Sampling

Environmental conditions can affect volatilization from the source as well as soil gas

movement in the subsurface. When planning to sample soil gas, it is important to be

aware of and document environmental conditions that may affect the representativeness

of the sample. Environmental conditions to note are listed below:

Barometric pressure

Changes in barometric pressure can lead to a pressure gradient between the soil gas and

atmosphere, creating a flow of soil gas to the surface during barometric lows and down

into the vadose zone during barometric highs. The potential effects decrease with

increasing sampling depth. Barometric pressure should be recorded when soil gas

samples are collected at depths shallower than 5 feet bgs. This information will assist the

investigator in interpreting soil gas data collected under different atmospheric conditions.

Temperature

Soil temperature can affect contaminant concentrations in soil gas because vapor pressure

and water solubility are temperature dependent. In Alaska, the temperature in shallow

soils and beneath shallow foundations (e.g., slab-on-grade) can vary significantly

between summer and winter. However, temperature variations decrease with depth in the

soil column. The effect of changes in soil temperature on vapor migration at Alaskan

sites is not known, but should be taken into consideration.

Precipitation

Infiltration from rainfall can affect soil gas concentrations by displacing the soil gas,

dissolving volatile organic compounds, and by creating a “cap” above the soil vapor.

Infiltration from large storms typically only penetrates several inches into the soil.

Therefore, soil gas samples collected at depths greater than 3 feet are unlikely to be

affected. Soil gas samples collected closer to the surface may be affected, so DEC

recommends measuring percent moisture of the soil when collecting shallow soil gas

samples during or shortly after a rainfall greater than 1 inch. This information will assist

the investigator interpret soil gas data collected at different soil moisture levels.

Indoor Air Sampling

Indoor air samples directly measure contaminant concentrations in a building and are

intended to represent the quality of the air that occupants are breathing. Indoor air sample

results provide direct information about current human exposure. Anytime indoor air

samples are collected, Step 1 should be revisited to determine if short-term risk is a

concern and if any agencies should be notified immediately.

In some situations, it may be preferable to collect indoor air samples before completing a

subsurface soil gas characterization. Examples of such situations may include the

following:

In response to a recent spill to evaluate acute risks.

If odors or monitoring equipment indicates an immediate risk.

29

If the source of vapors is so close to the structure that a soil gas sample cannot be

collected between the source and the foundation,

When preferential pathways into the structure (e.g., building sumps or drainage

pits, subsurface utility conduits or drains, or bedrock fractures) create a direct

conduit between the building foundation and the vapor-contaminant source.

DEC does not recommend collecting indoor air samples alone. Collected alone, indoor air

data are often inconclusive because of background interferences and the wide temporal

and spatial variability. Instead, DEC recommends using a multiple lines of evidence

approach when sampling indoor air (see Section VI, “Multiple Lines of Evidence”.

Other important guidelines when collecting or evaluating indoor air data include the

following:

Analytical methods must achieve detection limits below the screening levels (this

can be difficult for some compounds so verify with the laboratory).

Attempt to eliminate background interferences before sampling.

Collect the sample in a high-use area to represent the actual breathing zone.

Do not chill indoor air samples during sample transport.

Indoor Air Sample Location and Frequency

Indoor air samples should be collected in the lowest occupied level of the building. In

structures with basements that are not used for living space, consider sampling both the

occupied living areas and basement areas to better assess the pathway and the attenuation

occurring inside the house. DEC recommends collecting at least one indoor air sample

per 1,000 square feet of floor space. If fewer samples are proposed in the workplan, the

investigator should provide justification for reduced sampling. Larger buildings may

require additional samples, especially if they contain separate air spaces or air-handling

units.

Additional samples are usually necessary for multi-family residential units and

commercial or retail buildings. These types of buildings require a careful review of the

building features before deciding on sampling locations. Subsurface structures, such as

partial crawl spaces, sumps and elevators, may be present that would facilitate vapor

intrusion part of the building and not another.

The location and number of indoor air samples should account for different exposure

scenarios that exist within the building and any sensitive populations that may be exposed

to the contaminated vapors.

To evaluate trends in temporal variability, the investigator should sample at least twice

during the year to identify the effects of seasonal changes in weather, soil conditions, and

heating and ventilation characteristics of the building.

30

Indoor Air Sampling Procedures

Before collecting indoor air samples, the DEC’s Building Inventory and Indoor Air

Sampling Questionnaire (Appendix I) should be completed. The questionnaire enables

the investigator to document information on the building, the occupants, and potential

sources of background contaminants. The investigator should identify any penetrations

through the foundation, such as water, sewer, gas, electric, and telecommunication lines,

or sumps. Penetrations should be screened with portable monitoring equipment and may

need to be targeted for sampling.

A presampling building walkthrough should be completed at least 24 hours before

collecting indoor air samples. During the walkthrough, indoor vapor sources that could

interfere with detecting COCs intruding into the building from subsurface sources should

be removed if possible. The investigator may also choose to ventilate the building to

attempt to remove background contaminants.

To avoid potential interferences and dilution effects, occupants should make a reasonable

effort to avoid the following for 24 hours prior to sampling:

Opening any windows, fireplace dampers, openings, or vents;

Operating ventilation fans unless special arrangements are made;

Smoking in the building;

Painting;

Using wood stove, fireplace, or other auxiliary heating equipment (e.g., kerosene

heater);

Operating or storing automobiles in an attached garage;

Allowing containers of gasoline or oil to remain within the house or garage area,

except for heating fuel tanks, and these tanks should be vented to outside the

building or the vents should be temporarily sealed to prevent off-gassing inside

the structure;

Cleaning, waxing, or polishing furniture, floors, or other woodwork with

petroleum- or oil-based products;

Using air fresheners, scented candles, or odor eliminators;

Engaging in any hobbies that use materials containing volatile chemicals;

Using cosmetics, including hairspray, nail polish, nail polish removers,

perfume/cologne, etc.;

Lawn mowing, paving with asphalt, or snow blowing;

Applying pesticides;

Using building repair or maintenance products, such as caulk or roofing tar; and

Bringing freshly dry-cleaned clothing or furnishings into the building.

Samples should be collected in the breathing zone, approximately 3 to 5 feet off the

ground, in high-use areas. Sampling devices should be set to collect indoor air samples

over a 24-hour period or longer, even in commercial settings. DEC believes that

averaging samples over a longer time period best represents the exposure to most

occupants. DEC will consider sample duration alternatives on a case-by-case basis.

31

Considerations for Collecting and Using Indoor Air Data

Additional considerations for collecting indoor air data are provided below:

Temporal variability

A change in weather conditions, or in the building’s heating and ventilation, can lead to

variable vapor intrusion. Longer sampling times may compensate for some of this

variability, but indoor air sampling should be avoided during unusual weather conditions.

Although vapor intrusion is expected to be the most pronounced in the winter months, the

highest contaminant concentrations have been observed in late summer and fall in some

buildings in Alaska. Research suggests that the variability in indoor air contaminant

levels caused by vapor intrusion is typically less than one order of magnitude between

seasons (ITRC, 2007). However, this information may not pertain to Alaska where

extended cold and periods and tight building construction are typical.

Heating and ventilation systems

Air samples are sometimes designed to represent typical exposures in a mechanically

ventilated building and the operation of HVAC systems during sampling should be noted

on the Building Inventory and Indoor Air Sampling Questionnaire (Appendix I). When

samples are collected, the building’s HVAC system should be operating in a manner

consistent with normal operating conditions when the building is occupied (e.g., schools,

businesses, etc.). Unnecessary building ventilation should be avoided for 24 hours prior

to and during sampling. During colder months, heating systems should be operating to

maintain normal indoor air temperatures (i.e., 65 °F – 75 °F) for at least 24 hours prior to

and during the scheduled sampling time.

Background interferences

Common household products stored or used in buildings can interfere with the vapor

intrusion evaluation. The presampling survey in Appendix I can help identify background

sources in the indoor air environment. Portable vapor monitoring equipment readings

may also be useful for identifying sources in the building. When feasible, the investigator

should remove these sources at least 24 hours prior to sampling. Ventilating the building

may also reduce background contaminant levels. If ventilation is appropriate, it should be

completed 24 hours or more before the scheduled sampling time. Where applicable,

ventilation can be accomplished by operating the building’s HVAC system to maximize

outside air intake.

Analytical Methods and Sample Handling for Soil Gas and Indoor Air

The same sample containers and analytical methods can be used for both soil gas

sampling and indoor air. Some differences arise due to the higher concentrations

expected in soil gas than in indoor air. The following section provides guidelines for both

soil gas and indoor air sample handling and analysis, unless otherwise noted.

32

Sample Containers

DEC recommends summa canisters for the most defensible, quantitative air sampling in

the vapor intrusion evaluation. Canisters appear to provide more reliable sample integrity

than gas sample bags, particularly when samples are shipped via air, and they have longer

holding times than bags. In comparison to sorbents, canisters work with analytical

methods that often provide lower detection levels and concentration results rather than a

mass, which allow direct use of these results in risk calculations. However, sorbents,

bags, or other devices may be appropriate in certain circumstances. Additionally, there is

emerging technology with sorbents that may increase their appropriateness for this type

of site investigation.

Canisters

Stainless steel canisters are recommended for TO-14A, TO-15, or equivalent methods.

The sampling canister is a specially lined inert container sent to the field under vacuum

and certified clean and leak-free. A 100-percent canister cleaning certification may be

required for summa canisters when low detection levels are necessary. Canisters range in

volume from less than 1 liter to greater than 6 liters. The larger canisters are used for

ambient air samples, subslab samples, and integrated samples (collected over more than a

few minutes). One-liter samples are generally used for taking high concentration (i.e.,

greater than 5 parts per billion by volume) grab samples.

The canister fills with air at a fixed flow rate over a preset period of time with use of a

flow controller calibrated and set in the laboratory. Initial and final vacuums are recorded

for each canister. To ensure the canisters are filling at the proper rate, they should be

rechecked after deployment. Canisters must have dedicated vacuum gauges. The canister

must be retrieved prior to being completely filled (with some residual vacuum remaining)

to ensure proper collection.

Sampling personnel should take care to see that the valves and regulators provided with

the canisters can maintain sample container integrity during air cargo transport from

Alaska to the selected laboratory.

Sorbents

Samples are collected by drawing air at a calibrated flow rate through a tube containing a

sorbent media over a specified time period. The flow rate and sampling volume used are

determined based on the sorbent used, the COCs, and the amount (mass) of the sorbent

contained in the tube. The samples are taken to the laboratory for thermal or chemical

desorption and subsequent analysis. Reporting limits are based upon the amount of air

passed through the tube. It is important to use a sorbent certified clean that can be reliably

used for the collection and analysis of the COCs. The primary disadvantage of using

sorbents is that only one analysis is usually possible from a tube. Other complications of

sorbent sampling are potential compound breakthrough and sorbent contamination from

passive adsorption of VOCs.

33

Passive sampling

Passive sampling is similar to sampling with sorbents, but the collection method is based

on the diffusion of the compound onto the sorbent and does not rely on pumps. As an

advantage, the passive sampler is simply hung in the indoor air space to be sampled and

left for a predetermined period of time. After the exposure period, the sampler is placed

into an airtight container until analysis of the media is done. Exposure times (the amount

of time the sorbent is exposed to the contaminant) must be determined based on estimated

sample concentrations such that the sampler does not reach a state of equilibrium (or

saturation) with the environment, a common source of low bias.

A drawback to this type of sampling is that analytical results are given in units of mass,

not concentration, because the airflow across the sampler and the sampler uptake rate is

difficult to obtain accurately. There are a few passive samplers which can be used to

estimate contaminant concentration in the air (e.g., SKC Ultra® Passive Samplers or

Radiello® Passive Air Sampling System). These samplers have a high uptake rate and

typically use thermal desorption instead of solvent extraction for analysis. While these

samplers have greater sensitivity and are more appropriate for indoor air sampling, the

investigator must evaluate the method detection limit and the concentration estimate

carefully. Data obtained from these methods may be more useful for qualitatively

characterizing indoor air contamination than for evaluating risk. DEC approval should be

obtained prior to comparing data from any passive collection device to a target level.

Sample bags

Gas sample bags (e.g. Tedlar®, Teflon®, etc.) can be used with an evacuation chamber,

or lung box, to allow an air sample to be collected without the sample passing through a

pump. Samples collected in gas bags are typically analyzed with a field GC or mobile

laboratory. Tedlar bag sample holding time can be as low as a few hours and no more

than three days depending on the chemical. Gas sample bags may not be appropriate for

certain VOCs, including naphthalene. The use of gas sample bags and their suitability for

the target analytes should be carefully evaluated and described in the vapor intrusion

work plan.

Other sampling devices

Syringes can be used to withdraw a soil gas sample from a probe, and then injected

immediately into an analytical instrument, or into another sampling container, such as a

Tedlar bag. Glass cylinders or sampling bulbs are less common. Air is pulled through the

sample container by a pump, after which the inlet and outlet are sealed.

Sample Handling, Storage, and Transportation

Sample handling procedures should be followed to maintain sample integrity between the

time of collection and analysis.

Soil gas and air samples should not be chilled.

Changes in ambient pressure that the samples are exposed to should be

minimized. If air shipping is necessary, gastight vials or canisters are critical.

34

If condensation is observed in the sample container, the sample should be

discarded and a new sample collected.

For halogenated compounds (e.g., TCE, TCA, PCE), allowable containers must

be gas-tight but also opaque/dark to eliminate potential photodestructive effects.

Sample container valves should be double-checked to ensure they are tight and

secure.

Analytical Methods and QA/QC

A variety of analytical methods are available to measure indoor air samples, all of which

can give accurate results when followed with appropriate QA/QC procedures.

Table 5 presents a summary of analytical methods commonly used in vapor intrusion

investigations. The primary criteria for choosing the appropriate method are as follows:

Target COCs

Concentrations that may be encountered during sampling

Required detection level and other data quality objectives (DQOs)

Sampling logistics

Cost

The planning stages of the investigation should include discussions with the laboratory to

determine the detection levels achievable under each method. The detection level should

be lower than the default target levels for each COC. It may be appropriate to combine

analytical methods to achieve appropriate detection limits or determining contaminant

levels over a range of expected concentrations.

When petroleum biodegradation is being evaluated, oxygen (O2), carbon dioxide (C02),

and methane (CH4) should be included in soil gas sample analyses.

DEC will require that the analytical laboratory be certified by the National Environmental

Laboratory Accreditation Program (NELAP) for air or soil gas test methods used for

vapor intrusion investigations. The analytical laboratory should comply with its internal

QA/QC procedures, and follow the QA/QC requirements of the analytical method. The

laboratory should also comply with any project-specific data quality objectives (DQOs).

Field QC should include collecting duplicate samples to improve confidence in

the measured concentrations, and may include field blanks collected to assess

contamination from shipping and handling, if that is a concern.

Laboratory QA should include instrument blanks, method blanks, matrix spike

and matrix spike duplicate samples, and laboratory control samples.

Specific project QA/QC DQOs should be defined in the workplan.

35

Table 5: Summary of analytical methods for soil gas, indoor and ambient air samples.

(Modified from ITRC Guidance, Appendix D, Table D-3)

Parametera Method Collection device

Descriptionb

Method holding time Reporting limitc

Approximate

Cost

VOLATILE ORGANIC COMPOUNDS (VOCS)

BTEX, MTBE, TPH TO-3 Tedlar bag or canister GC/FID 30 days for canister ,

48 hours for Tedlar bag

1–3 μg/m3 $165-$220

Nonpolar VOCs TO-14A Canister GC/ECD/FID 30 days for canister 1–3 μg/m3 $165-$220

or GC/MS

Polar and nonpolar TO-15 Canister GC/MS 30 days for canister 1–3 μg/m3 $165-$220

VOCs

Low-level VOCs TO-15 SIM Canister GC/MS 30 days 0.011–0.5 μg/m3 $180-$230

Polar and nonpolar

VOCs

TO-17 Sorbent tube GC/MS 30 days 1–3 μg/m3 $225

VOCs 8021B

modified

Syringe, Tedlar bag, glass vial GC/PID On-site analysis for syringe,

48 hours for Tedlar bag,

30 days for glass vial

10–60 μg/m3 $95

VOCs 8260B

modified

Syringe, Tedlar bag, glass vial GC/MS On-site analysis for syringe,

48 hours for Tedlar bag,

30 days for glass vial

50–100 μg/m3 $130

SEMI-VOLATILE ORGANIC COMPOUNDS (SVOCS)

SVOCs TO-13A High-volume collection (may

require large sample volume, e.g.,

300 m3)/PUF/XAD media

GC/MS Extracted within 7 days of

collection and analyzed

within 40 days of extraction

5–10 μg/sample $210-$250

Low-level olycyclic

aromatic

hydrocarbons

(PAHs)

TO-13A SIM High-volume collection (may

require large sample volume, e.g.,

300 m3)/PUF/XAD media

GC/MS Extracted within 7 days of



0.5–1 μg/sample $150

36

Table 5, continued: Summary of analytical methods for soil gas, indoor and ambient air samples. (Modified from ITRC Guidance, Appendix D, Table D-3)

Parametera Method Sample media/storage Description

b Method holding time Reporting limit

c

Approximate

Cost

PESTICIDES AND POLYCHLORINATED BIPHENYLS (PCBS)

Pesticides and PCBs TO-4A or TO-10A High-volume collection (may

require large sample volume,

e.g., 300 m3)/PUF media

GC/ECD Extracted within 7 days of



Pesticides: 0.5– 1

μg/sample, PCBs:

1–2 μg/sample

$150-$180

FIXED GASES

Fixed gases

(methane, nitrogen,

oxygen)

USEPA 3C Canister or Tedlar bag GC/FID 48 hours for Tedlar bag,

30 days for canister

1000–2000 μg/m3 $95-$130

Fixed gases

(methane,

ASTM D-1946 Canister or Tedlar bag GC/TCD/FID 48 hours for Tedlar bag,


1000–2000 μg/m3 $95-$130

nitrogen, oxygen,

carbon dioxide,

carbon monoxide)

Natural gases ASTM D1945 Canister or Tedlar bag GC/FID 48 hours for Tedlar bag,


1000–2000 μg/m3 $75-$165

TPH–ALKANES

C4–C24 8015 mod. Canister or Tedlar bag GC/FID 48 hours for Tedlar bag,


10 ppmv $120

C4–C12 8260 Canister or Tedlar bag GC/MS 48 hours for Tedlar bag,


1 ppmvd $130

C4–C12 TO-15 Canister or Tedlar bag GC/FID 48 hours for Tedlar bag,


0.1 ppmv $150

METALS

Mercury Niosh 6009 Sorbent Tube GC/MS - - - a This is not an exhaustive list. Some methods may be more applicable in certain instances. Other proprietary or unpublished methods may also apply. These methods may be used

for soil gas, indoor air, or ambient air – but the reporting limit should be compared to the level expected in the sample or the standard to which the sample will be compared. b ECD = electron capture detection, FID = flame ionization detection, GC = gas chromatography, MS = mass spectrometry, PID = photoionization detection, TCD = thermal

conductivity detection c Reporting limits are compound specific and can depend upon the sample collection and the nature of the sample. Detection limits shown are for the range of compounds reported

by the analytical methods. d The indicated methods use a sorbent-based sampling technique. The detection limits will depend on the amount of air passed through the media.

37

Confusion with units: microgram per cubic meter, microgram per liter, and parts per

billion by volume are not equivalent reporting units. An on-line conversion tool is

available at www.handpmg.com.

Applying improper soil gas screening levels: residential levels applied to industrial

settings, errors with attenuation factors.

Improperly installed subslab probes: grouting techniques should ensure proper seal

between the probe and walls of the hole drilled through the slab and leak detection should

be completed at each soil gas sampling point.

Leaking canister valves: under- or over-tightening summa canister valves can result in

loss of vacuum during canister shipping.

Dirt in canisters: using filters can prevent dirt either entering the canister or plugging the

valve.

Flawed canister gauges: canister gauges may not function properly causing uncertainty in

canister vacuums.

Misusing flow controllers: using a flow controller that has been inaccurately set, or

applied to the wrong sample point (e.g., 24-hour vs. 2-hour), will alter the collected

sample volume.

VI. INVESTIGATIVE STRATEGIES – SPECIAL CONSIDERATIONS

Data collected or used in a vapor intrusion evaluation can be complex and may appear

contradictory at times. It is important to interpret each data set carefully and weigh the relative

significance of any one line of evidence. Decisions about vapor intrusion are seldom based on a

simple comparison of a few samples to a target level. Many aspects of a site, including the

interaction between buildings and their environment, may affect the interpretation of data and

subsequent decisions about the site. This section describes different ways to interpret data that

are acceptable to DEC.

Background Air Levels

Volatile chemicals are often present in a building due to both indoor and outdoor air quality

problems that are not associated with vapor intrusion. While these problems can result in health

effects, DEC only has the authority to regulate vapor intrusion problems. DEC recommends

sampling subslab and indoor air simultaneously to assist with this evaluation; however,

comparing indoor air data to typical background levels may also be useful.

Typical background levels from indoor air quality studies in North American residences are

provided in Appendix H. These levels are reported here as the 25th

, 50th

, 75th

, and 95th

percentiles

of the arithmetic mean concentrations observed in indoor air from numerous studies reviewed

and compiled by Dawson and McAlary (2008). DEC recommends comparing indoor air data to

the 50th

percentile to determine if background interference may be present. However, higher

percentiles may be considered when other factors suggest background sources are present.

The background levels shown in Appendix H are based on data collected primarily in warmer

climates. Normal background levels may be different in some areas of Alaska where building

construction practices and long periods of cold weather may cause less building ventilation and

greater airflow from the subsurface. Some data describing background indoor air quality in

Alaska is available, as described below.

38

Schlapia and Morris (1998) reported that benzene concentrations in the majority of 137 homes

sampled in the Anchorage area were less than 16 micrograms per cubic meter (µg/m3) or 5 parts

per billion by volume (ppbv). Approximately one-fourth of the homes had indoor benzene

concentrations greater than 32 µg/m3 (10 ppbv). Homes with attached garages, especially those

where the living space was located above the garage, had significantly higher concentrations of

benzene indoors. The Cold Climate Housing Research Center in Fairbanks, Alaska, analyzed

indoor air samples from three Fairbanks homes and two Juneau homes that were built with tight

construction to meet energy efficiency standards. Benzene concentrations in the Fairbanks homes

ranged from 32 to 62 µg/m3 (10 to 19 ppbv). Benzene was not detected in the Juneau homes,

possibly because of their lack of attached garages.

Multiple Lines of Evidence

When multiple lines of evidence have been gathered, indoor air quality should not be used as a

sole indicator of vapor intrusion potential. Other factors can contribute to indoor air quality, such

as chemicals stored on site or background air quality. Indoor air data should be evaluated

concurrently with outdoor air to determine if outdoor, but aboveground sources, may be

contributing to contaminants observed indoors. If outdoor air quality appears to be affecting

indoor air quality, the outdoor air contaminant levels may be subtracted from the indoor air

contaminant levels.

Indoor air data should also be compared to the subslab or near-slab soil gas data. If contaminant

concentrations in indoor air exceed the contaminant concentrations in subslab or near-slab soil

gas data, background contaminant sources should be considered. This condition may indicated

that vapor intrusion is not occurring, or may not be occurring at significant levels and further

investigation should be focused on identifying the background source or clarifying its

contribution to risk.

When multiple lines of evidence data are available, site-specific attenuation factors between soil

gas and indoor air should be calculated as described by EPA (2006). Field data collected to date

indicate that attenuation factors greater than 0.01 are usually attributable in part to background

sources.

Predictive Modeling

If data indicate concentrations greater than generic target levels, predictive modeling may be

used to evaluate the potential for vapor intrusion into overlying buildings. When using a model, a

table describing site-specific parameters, the basis for using these parameters, and a copy of the

model input and results pages should be provided to DEC.

DEC will accept the use of EPA’s vapor intrusion models based on Johnson and Ettinger (1991).

EPA provides spreadsheet versions of this model for use with soil gas and groundwater data at

http://www.epa.gov/oswer/riskassessment/airmodel/johnson_ettinger.htm. Because of DEC’s

concerns about modeling vapor intrusion risk based on soil data, the soil and NAPL versions

included on this website should not be used to rule out a vapor intrusion evaluation. DEC also

recommends that the Johnson and Ettinger model not be used for evaluating petroleum-

hydrocarbon spills unless the investigator considers adjusting the modeled attenuation factor for

biodegradation. Other models may be used if they are publicly available, peer-reviewed, and

approved by DEC for predicting risk to building occupants.

http://www.epa.gov/oswer/riskassessment/airmodel/johnson_ettinger.htm

39

Risk Assessment

When residential or commercial exposure assumptions over-estimate the exposure at the site, a

risk assessment may be completed to alter the exposure assumptions. Similarly, DEC may

require a risk assessment when there is concern that the residential exposure assumptions are not

protective enough for people occupying a building of concern. Before conducting a risk

assessment, a risk assessment workplan must be completed in accordance with the DEC’s Risk

Assessment Procedures Manual (2009) available at

http://dec.alaska.gov/spar/csp/guidance/rapm02_09.pdf and approved by DEC.

Petroleum Biodegradation

In Alaska, many sites contain petroleum contamination close to or beneath a building. Vapor

intrusion investigations at these sites are often complicated by numerous sources of petroleum in

the building and outside the building that can make it difficult to interpret indoor air samples.

Evaluating biodegradative conditions can be a useful alternative at these sites.

In regions of active aerobic biodegradation, micro-organisms living in the soil will consume

petroleum vapors, using O2 and producing CO2. Biodegradation can cause petroleum vapors to

attenuate rapidly as they move away from the source. However, when the source is highly-

concentrated or conditions prevent oxygen from being replenished in the soil, oxygen-depleted

zones may occur near the source. As the oxygen levels decline, biodegradation will be limited,

and petroleum vapors will no longer attenuate rapidly. Anaerobic decomposition can also occur

in the oxygen-depleted source zones, generating CH4. Methane gas undergoes aerobic

biodegradation in the more oxygen-rich subsurface regions (API, 2005).

Petroleum vapors will often degrade before reaching a building as long as clean, oxygenated soil

is present between the vapor source and the building foundation (Hers et al., 2000; Davis, 2008).

Davis (2008) has shown that biodegradation will prevent vapor intrusion when the source

strength is low, at least two feet of fine-grained soil or 5 feet of coarse-grained soil is present,

and the soil contains at least 3 percent oxygen. Because the DEC target levels do not reflect the

effects of biodegradation, DEC may not require further evaluation for vapor intrusion at sites

where existing data suggests that the conditions described above exist. However, a more

thorough evaluation of the biodegradation potential will be required when the following

conditions are present:

Soil samples contain petroleum compounds above DEC’s most stringent cleanup levels in

the soil within 5 feet of the foundation.

Free product is present on the groundwater surface beneath the building and within 30

feet of the building foundation; under these conditions biodegradation may be using

oxygen at a faster rate that it can be replenished.

A cap, such as concrete or asphalt, covers the area around the building, potentially

preventing oxygen from flowing into the subsurface.

In order to evaluate if biodegradation is occurring, DEC recommends including fixed gasses (O2,

CO2, and CH4) as analytes in soil gas samples collected during a petroleum investigation (see

Table 5). Fixed gases also can be evaluated using portable monitoring equipment.

http://dec.alaska.gov/spar/csp/guidance/rapm02_09.pdf

40

VII. MITIGATING A VAPOR INTRUSION PROBLEM

Mitigation systems can be installed during construction to prevent vapor intrusion, or can be

retrofitted into an existing structure. Radon mitigation systems have been successfully used to

address other chemical intrusion. For guidance on mitigation systems, see Section 4 of the ITRC

Guidance (ITRC, 2007). The University of Alaska has also produced a useful reference for

mitigating radon gas problems specific to Alaska (Siefert, 2003). Systems thought to be most

effective in Alaska include:

Subslab depressurization systems or soil gas venting systems. These types of systems

should be designed to establish and maintain lower subsurface soil vapor pressures both

below and adjacent to the structure than exist within the structure. Routine maintenance

and inspection of the system may be required until acceptable cleanup levels are met in

the subsurface.

Air vapor barriers beneath the foundation. The vapor barrier should be impermeable to

the contaminants of concern and adequate sealing of the barrier along with any cracks or

perforations in the foundation must be done. A smoke test may be required to confirm

that the barrier is not leaking.

If a mitigation system is used to manage the risk in a specific building, the responsible party

must demonstrate to the DEC that the system is effective at controlling vapor migration into that

building. Demonstrating abatement may include smoke tests or tracer gas tests, subslab soil gas

or indoor air sampling, or other measurements that characterize how the system interacts with

building characteristics, such as subslab pressure differentials.

Other engineered mitigation systems may be proposed. However, the system must be designed to

prevent vapor intrusion for the chemicals of concern and the system should be operated,

maintained, and monitored under a DEC-approved plan. Positive pressure ventilation systems

may not be feasible in residential construction in Alaska because positive interior pressures force

moist air into the building, causing moisture-related problems. Balanced ventilation systems,

such as heat recovery systems, have not been shown to be effective with radon problems, and are

not recommended for other contaminant problems (Siefert, 2007).

VIII. INSTITUTIONAL CONTROLS AT VAPOR INTRUSION SITES

Institutional controls are usually established once investigation of the vapor intrusion pathway is

complete and remedial efforts have been completed or are underway. In some cases, especially

where a more immediate threat is identified (see Step 1), DEC may require institutional controls

for the site before the investigation is finished. Once DEC determines that all exposure pathways

have been evaluated and the cleanup is protective of human health and the environment, the DEC

will issue a closure decision. Institutional controls for the vapor intrusion pathway may remain

after cleanup is complete until contaminant concentrations diminish to safe levels.

Typically, institutional controls are necessary when:

Physical or mechanical barriers, such as remediation systems, ventilation systems, and

vapor barriers, are used or relied on to reduce vapor intrusion. Institutional controls

41

should be established to ensure these mitigation measures are maintained and operated

correctly.

New construction or changes to the existing structures could result in new vapor intrusion

pathways. Institutional controls should be established to ensure that the vapor intrusion

pathway is re-evaluated following any new construction and/or structure remodeling.

The site has been evaluated for commercial or industrial use, but not for residential use.

Institutional controls should be established to restrict land use changes or to ensure the

risk of residential use is evaluated.

IX. RFERENCES

API, 2005. Collecting and Interpreting Soil Gas Samples from the Vadose Zone, A Practical

Strategy for Assessing the Subsurface Vapor-to-Indoor Air Migration Pathway at Petroleum

Hydrocarbon Sites. Amercian Petroleum Institute. API Publication No. 4741. Available at:


Davis, Robin, 2006. “Vapor Attenuation in the Subsurface from Petroleum Hydrocarbon

Sources: An Update and Discussion on the Ramifications of the Vapor-Intrusion Risk Pathway.”

LUSTLine Bulletin 52, May.

Davis, Robin. 2008. “Nationwide Study of Subsurface Petroleum Hydrocarbon Vapor

Occurrence & Attenuation.” A Summary of Research Results from 20th

Annual National Tanks

Conference, March 16-19.

http://www.neiwpcc.org/tanks08/presentations/davis.hartman.hopkins.ririe.pdf.

DEC. Cleanup Levels Guidance. Alaska Department of Environmental Conservation. June.

Available at: http://dec.alaska.gov/spar/csp/guidance/cleanuplevels.pdf

DEC Monitoring Well Guidance. Alaska Department of Environmental Conservation. February.

Available at: http://dec.alaska.gov/spar/csp/guidance/mw_guidance.pdf

DEC Policy Guidance on Developing Conceptual Site Models (draft). Alaska Department of

Environmental Conservation. Available at:

http://dec.alaska.gov/spar/csp/guidance/csm05_draft.pdf

DEC Underground Storage Tank Procedures Manual. Alaska Department of Environmental

Conservation. June. Available at: http://dec.alaska.gov/spar/ipp/docs/ust_man02_10_07.pdf

DTSC, 2003. Advisory – Active Soil Gas Investigations. California Department of Toxic

Substances Control. Available at: http://www.dtsc.ca.gov/lawsregspolicies/policies/SiteCleanup/upload/SMBR_ADV_activesoilgasinvst.pd

f

EPA, 2002. OSWER Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway

from Groundwater and Soils (Subsurface Vapor Intrusion Guidance). EPA 530-D-02-004.

Environmental Protection Agency. Available at: http://epa.gov/osw/hazard/correctiveaction/eis/vapor.htm

EPA, 2006. Assessment of Vapor Intrusion in Homes Near the Raymark Superfund Site Using

Basement and Sub-Slab Air Samples. EPA/600/R-05/147. Environmental Protection Agency.

Cincinnati, OH. Available at: http://www.dec.state.ak.us/spar/csp/guidance/raymark6report.pdf


http://dec.alaska.gov/spar/csp/guidance/cleanuplevels.pdf

http://dec.alaska.gov/spar/csp/guidance/mw_guidance.pdf

http://dec.alaska.gov/spar/csp/guidance/csm05_draft.pdf

http://dec.alaska.gov/spar/ipp/docs/ust_man02_10_07.pdf





42

EPA, 2008. User’s Guide for Regional Screening Levels (RSL) for Chemical Contaminants at

Superfund Sites. Environmental Protection Agency. September.

EPRI, 2005. Reference Handbook for Site-Specific Assessment of Subsurface Vapor Intrusion to

Indoor Air. Electric Power Research Institute. Palo Alto, CA. Available at: http://my.epri.com/

Health Canada, 2007. Final Draft Report on Soil Vapour Intrusion Guidance for Health Canada

Screening Level Risk Assessment (SLRA), Volume 1. Golder Associate Ltd., Burnaby, British

Columbia. July.

ITRC, 2007. Vapor Intrusion Pathway: A Practical Guideline. Interstate Technology and

Regulatory Council, Vapor Intrusion Team. Washington, DC. January. Available at:


Johnson, P.C. and R. A. Ettinger. 1991. ”Heuristic model for predicting the intrusion rate of

contaminant vapors into buildings”. Environ. Sci. Technology 25:1445-1452.

MA DEP, 2004. Indoor Air Sampling and Evaluation Guide. Massachusetts Department of

Environmental Protection. WSC Policy No. 02-430. Available at: http://www.mass.gov/dep/cleanup/laws/02-430.pdf

NJ DEP, 2005. Vapor Intrusion Guidance. New Jersey Department of Environmental Protection.

Available at: http://www.nj.gov/dep/srp/guidance/vaporintrusion/vig.htm

NY DOH, 2006. Guidance for Evaluating Soil Vapor Intrusion in New York State. New York

State Department of Health. Available at: http://www.health.state.ny.us/environmental/investigations/soil_gas/svi_guidance/

Schlapia, A. and S.S. Morris. 1998. “Architectural, Behavioral and Environmental Factors

Associated with VOCs in Anchorage Homes”. Presented at the Air & Water Management

Association’s 91st Annual Meeting & Exhibition, June 14-18, 1998, San Diego, California.

SDC, 2009. Site Assessment and Mitigation Manual. San Diego County. Available at: http://www.co.san-diego.ca.us/deh/water/sam_manual.html

Siefert, 2007. Radon Mitigation: Alaska Experiences, Costs, Results. RAD-00755. University of

Alaska, Cooperative Extension Service.

Hydrasleeve® is a registered trademark of EnviroEquip.

SKC Ultra® is a registered trademark of SKC, Inc.

Radiello® is a registered trademark of Fondazione Salvatore Maugeri IRCCS.

Tedlar® and Teflon® are registered trademarks of E.I. du Pont de Nemours and Company.

http://my.epri.com/






APPENDIX A

Elements of the Vapor Intrusion Pathway

(adapted from NJ DEP, 2005)

A-1

Assessing the potential for vapor intrusion to indoor air should begin with visualizing a

simplified version of the site or physical setting; this simplified idea, picture, or description is

part of the overall CSM. The basic components of a CSM are known or suspected contaminant

sources, contaminant migration pathways, potential human receptors and the exposure routes by

which these receptors may come in contact with contaminants on a site-specific basis. This

appendix focuses on the conceptual framework of the process of vapor intrusion. The following

subsections describe the components of the CSM in detail:

Sources of vapor intrusion

Vapor Migration Mechanisms and

Receptors

Sources of Vapor Intrusion Initial consideration in the preparation of a CSM should be centered on whether there is a vapor

source with the potential to cause vapor intrusion. In general, a vapor source of vapor intrusion

can be defined as the presence, or reasonably suspected presence, of a chemical of sufficient

volatility and toxicity in the subsurface with sufficient mass and/or concentrations to pose a

possible inhalation risk within current or future occupied overlying enclosures. This definition

includes the presence of a volatile chemical or chemicals adsorbed to, or in the pore

space/fractures of unsaturated soil or rock, or in the uppermost portions of the saturated zone.

Such vapor sources can exist in the form of: free phase or residual NAPL above or near the top

of the saturated zone; contaminated soil in the vadose zone; and shallow dissolved phase

contamination in ground water. Another possible source of subsurface vapor intrusion is the

release of volatile compounds in the vapor phase from underground tanks or piping and certain

types of aboveground facilities that use volatile compounds during operations. This particular

source is commonly referred to as a “vapor cloud.” Sources of indoor air contamination not

associated with vapor intrusion (e.g., ambient air, building materials, consumer products) should

also be considered when developing and evaluating this pathway.

Vapor Migration Mechanisms

When a chemical of sufficient volatility and toxicity is present in the subsurface, there are

several transport mechanisms by which the chemicals can migrate. The CSM should identify the

major and minor migration pathways and processes through which a receptor can be exposed at a

particular site. The four main transport mechanisms that should be considered are described and

illustrated below.

Diffusion of vapors from sources in the unsaturated zone

Diffusion of vapors from sources in shallow ground water

Advective and convective transport of vapors

Vapor migration through preferential pathways

Diffusion occurs as a result of a concentration gradient between the source and the surrounding

area; it can result in the upward, lateral or downward migration of vapors through the vadose

zone. The location of the source is an important factor influencing the direction of vapor

migration. Identifying soil gas concentration gradients may help determine the location of

unidentified vapor sources. Vapors can migrate in any direction including lateral and downward

directions from sources in the unsaturated zone. Variability in site characteristics, such as soil

A-2

porosity, effective permeability, ground surface cover, ambient temperature and age of a release

may increase or decrease the distance vapors migrate. A relatively impermeable surface cover

above a vapor source for example, may increase the distance a vapor plume would travel

laterally if it significantly impedes vapors from escaping to the atmosphere.

Diffusion of vapors from sources in the unsaturated zone


area; it can result in the upward, lateral or downward migration of vapors through the vadose

zone. The location of the source is an important factor influencing the direction of vapor

migration. Consequently, identifying soil gas concentration gradients may help determine the

location of unidentified vapor sources. Variability in site characteristics, such as soil porosity,

effective permeability, ground surface cover, ambient temperature and age of a release may

increase or decrease the distance vapors migrate. A relatively impermeable surface cover above

a vapor source for example, may increase the distance a vapor plume would travel laterally if it

significantly impedes vapors from escaping to the atmosphere.

Diffusion of vapors from sources in shallow ground water


area; in this case, the source is shallow groundwater contamination and/or NAPL. This can result

in the upward or lateral migration of vapors through the vadose zone. Diffusion of vapors in the

vadose zone from shallow ground water contamination depends on the hydraulic conductivity,

hydraulic gradient, aquifer heterogeneity, time since chemicals were released and natural

attenuation processes, the distribution of volatile chemicals in ground water may extend

considerable distances.

Within a set volumetric space where contaminated ground water is the only source of vapors in

the subsurface, the total mass of compounds volatilizing from ground water and diffusing

through the vadose zone (vertical mass flux) cannot exceed the total mass of volatiles moving

through that space laterally in ground water. For aquifers with slower ground water velocity, the

lateral mass flux in shallow ground water leaving the source area may be the limiting factor in

vapor intrusion impacts.

Advective and convective transport of vapors

The horizontal and vertical movement of vapors located near a building foundation is often

affected within an area referred to as the “zone of influence”. Chemicals

entering this zone are drawn into the building via soil gas advection and convection resulting

from building interiors that exhibit a negative pressure relative to the outdoors and the

surrounding soil. The reasons for this pressure differential include: 1) factors relating to

operation of HVAC system including inadequate combustion or makeup air and unbalanced air

supply and exhaust systems; 2) the use of fireplaces and other combustion sources, which results

in venting of exhaust gases to the exterior; 3) the use of exhaust fans in bathrooms and kitchens;

4) higher temperatures indoors relative to outdoors during the heating season or as a result of

solar radiation on rooftops; and 5) pressure exerted on the wall of a building caused by wind

movement over the building (Bernoulli’s principle). The combination of these actions and

conditions results in a net convective flow of soil gas from the subsurface through the building

foundation to the building interior. As would be expected from the above list, indoor air volatile

concentrations are generally higher during the heating season in homes affected by vapor

intrusion.

A-3

The rate of contaminant entry through the foundation and the air exchange rate of the building

will determine the concentration of the contaminants in the home resulting from vapor intrusion.

A similar pattern of soil gas movement can occur around buildings without a basement or around

those without any concrete foundation slab. Advective and convective transport of vapors can

occur in other scenarios. It has been observed that certain commercial and business operations

may result in volatile organic vapors entering the unsaturated zone solely as a vapor possibly due

to density differences between these vapors and the atmosphere. These operations could include

tetrachloroethene (PCE) dry cleaning units, vapor degreasers in machine shops, spray booths in

inking or painting facilities using chlorinated solvent based inks or paints, and

USTs/underground piping. Highly permeable deposits and very high vapor concentrations are

necessary for there to be significant density dependent transport below ground, therefore this

scenario is likely to be relatively rare. Contaminated soil vapor may also occasionally result from

pressurized buildings forcing contaminated indoor air out through openings in the foundation and

into nearby soil. The affected area or zone of influence would likely be relatively small, but

could affect subslab or other soil gas samples collected below buildings or structures such as

those described above. Another possible advective vapor transport mechanism, called

“barometric pumping,” is caused by cyclic changes in atmospheric pressure. These changes

create a “piston like” force on soil gas, possibly causing a cyclic up and down flow of

contaminant vapors in the affected interval. The magnitude of a barometric pressure cycle is

typically a small percentage of atmospheric pressure and its effect decreases with depth. The soil

texture, soil air permeability, and moisture content affect the depth to which the pressure change

may affect vapor transport. Soil gas compression and expansion in response to barometric

pressure fluctuations may alternately enhance or inhibit vapor intrusion. In areas subject to tidal

fluctuation or rapid increases in the groundwater elevation due to stormwater runoff, increasing

groundwater elevation may enhance advective transport.

Vapor migration through preferential pathways

In preparation of each CSM, investigators may look for the presence and locations of natural and

manmade pathways in the subsurface with high gas permeability through which vapors can

rapidly migrate. The term preferential exposure pathway can be defined as a natural (e.g.,

shallow rock or vertically fractured soil) or manmade (e.g., buried utilities) feature that creates a

sufficiently direct pathway from a source to a receptor. Shallow utilities buried at a depth that is

insignificant with respect to the column of soil between the building foundation and the source

do not automatically constitute a preferential pathway, nor should this definition include surface

paving outside the building or the presence of crushed stone beneath the slab as normally placed

for slab foundation material. Naturally occurring fractures and soil pores may facilitate vertical

or horizontal vapor migration while anthropogenic features such as utility conduits would likely

facilitate horizontal vapor migration due to their shallow depth. Buildings that are, or may

become, inhabited should be evaluated if they are associated with a preferential pathway that is

within some reasonable distance of a source area (based on professional judgment). Investigators

should also evaluate the potential for vapor intrusion in situations where a preferential pathway

leading to a structure runs near to, or through, a source area. For sources containing aerobically

degradable contaminants, however, it is unlikely that sufficient vapors will reach the structure to

result in a vapor intrusion problem unless the pathway and structure are both very close to the

vapor source. Biodegradation of benzene, toluene, ethylbenzene, and xylene (BTEX) vapors in

the vadose zone has been shown to be a very efficient process as long as sufficient oxygen is

available. Thus, if a preferential pathway is not close to a source area, biodegradable vapors

A-4

would likely degrade before reaching the pathway and/or within the pathway before reaching the

structure.

Receptors

A receptor can be defined as any human, plant, or animal that may be affected by a contaminant

from a contaminated site. The primary vapor intrusion receptors are the human occupants of

enclosed spaces that are impacted from migration of subsurface volatile compounds. Exposure to

volatiles can result in health problems to individuals occupying a building subject to vapor

intrusion. Enclosed spaces or buildings, for the purpose of this appendix, are defined as any

structure currently or potentially impacted by subsurface volatile contaminants. To account for

possible change in future use, vapor intrusion is of potential concern in buildings and enclosed

spaces whether or not they are currently occupied. Buildings with significant air exchange rates

(e.g., commercial garages and spaces with large doors or openings) or significantly limited use

(e.g., small utility sheds) will be evaluated on a site-specific basis. Human exposure typically can

take place under a residential (unrestricted use) or nonresidential (restricted use) exposure

scenario. Residential settings include single family homes, townhouses, and apartment buildings.

Receptors under a residential exposure scenario consist of both adults and children who are

expected to spend a greater period of time in a residential setting than those individuals in a

nonresidential setting. It is DEC’s policy that day care centers and schools are evaluated as a

residential use due to the potentially sensitive nature of the exposed population (children).

Nonresidential settings include office buildings and commercial or industrial complexes.

Nonresidential receptors consist of adult workers in the above buildings or complexes.

Nonresidential settings with sensitive populations (e.g., working pregnant women) will be

handled on a site-specific basis. Occupational settings that fall under the purview of OSHA may

be handled differently than those not subject to OSHA regulations when indoor air

concentrations from normal operating practices cannot be ruled out.

APPENDIX B

ATSDR Inhalation Minimal Risk Levels

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Appendix B: ATSDR Inhalation Minimal Risk Levels1

CAS

Number

Hazardous Substance Acute2 Intermediate

3 Chronic

4

µg/m3

ppbv µg/m3 ppbv µg/m

3 ppbv

67-64-1 Acetone 60,000 30,000 30,000 10,000 30,000 10,000

71-43-2 Benzene 30 9 20 6 10 3

111-44-4 Bis(2-chloroethyl)ether NA NA 100 20 NA NA

75-15-0 Carbon Disulfide NA NA NA NA 900 300

56-23-5 Carbon Tetrachloride NA NA 200 30 200 30

75-00-3 Chloroethane 40,000 15,000 NA NA NA NA

67-66-3 Chloroform 500 100 200 40 100 20

106-46-7 1,4-Dichlorobenzene 10,000 2,000 1,000 200 60 10

107-06-2 1,2-Dichloroethane NA NA NA NA 2,000 600

75-35-4 1,1-Dichloroethene NA NA 80 20 NA NA

156-60-5 trans-1,2-Dichloroethylene 800 200 800 200 NA NA

78-87-5 1,2-Dichloropropane 200 50 30 7 NA NA

542-75-6 1,3-Dichloropropene NA NA 40 8 30 7

100-41-4 Ethylbenzene 40,000 10,000 3,000 700 1,000 300

77-47-4 Hexachlorocyclopentadiene NA NA 100 10 2 0.2

67-72-1 Hexachloroethane 60,000 6,000 60,000 6,000 NA NA

302-01-2 Hydrazine NA NA 5 4 NA NA

7439-97-

6

Mercury (elemental) NA NA NA NA 0.2 0.02

75-09-2 Methylene Chloride 2,000 600 1,000 300 1,000 300

1634-04-

4

MTBE 7,000 2,000 2,000 600 2,000 600

91-20-3 Naphthalene NA NA NA NA 4 1

100-42-5 Styrene 9,000 2,000 NA NA 900 200

127-18-4 Tetrachloroethylene (PCE) 1,000 200 NA NA 300 40

108-88-3 Toluene 4,000 1,000 NA NA 300 80

71-55-6 1,1,1-Trichloroethane 10,000 2,000 4,000 700 NA NA

79-01-6 Trichloroethylene (TCE) 10,000 2,000 500 100 NA NA

96-18-4 1,2,3-Trichloropropane 2 0.3 NA NA NA NA

1330-20-

7

Xylenes (total) 9,000 2,000 3,000 600 200 50

Notes:

ATSDR – Agency for Toxic Substance & Disease Registry

µg/m3 – micrograms per cubic meter

ppbv – parts per billion by volume

NA – not available

1. Minimal risk levels were last updated 10/27/2008.

2. Acute levels are developed for exposure periods of 14 days or less.

3. Intermediate levels are developed for exposure periods of 15 to 364 days.

4. Chronic levels are developed for exposure periods of 365 days or more.

APPENDIX C

Conceptual Site Model Checklist

(from ITRC, 2007)

C-1

Conceptual Site Model Checklist (ITRC, 2007)

The information included in this checklist may be useful for developing a site-specific

conceptual migration model and in planning soil gas sampling. The investigator may use this

checklist to compile information for each site.

Utilities and Process Piping

Locate and map out all underground utilities near the soil or groundwater impacts. Pay

particular attention to utilities that connect impacted areas to occupied buildings.

Locate and map out all underground process piping near the soil or groundwater impacts.

Buildings (Receptors)

Locate and map out existing and potential future buildings. Identify the occupancy and

use of the buildings (e.g., residential, commercial). You may need to interview occupants

to obtain this information.

Describe the construction of the building including materials (e.g., wood frame, block),

openings (e.g., windows, doors), and height (e.g., one story, two story, multistory).

Determine whether there is an elevator shaft in the building.

Describe the foundation construction:

Type (e.g., basement, crawl space, slab on grade)

Floor construction (e.g., concrete, dirt)

Depth below grade

Describe the HVAC system in the building:

Type (e.g., forced air, radiant)

Equipment location (e.g., basement, crawl space, utility closet, attic, roof)

Source of return air (e.g., inside air, outside air, combination)

System design considerations relating to indoor air pressure (e.g., positive

pressure is often the case for commercial buildings)

Describe subslab ventilation systems or moisture barriers present on existing buildings, or

identify building- and fire-code requirements for subslab ventilation systems (e.g., for

methane) or moisture barriers below foundations.

Source Area

Locate and map out the source area for the vapor-phase contaminants related to the

subsurface vapor intrusion pathway.

Describe the presence, distribution, and composition of any NAPL at the site.

Identify the vapor-phase contaminants that are to be considered for the subsurface vapor

intrusion pathway.

C-2

Describe the status and results for the delineation of contamination in environmental

media, specifically soil and groundwater, between the source area and the potential

impacted buildings.

Describe the environmental media (e.g., soil, groundwater, both) containing

contaminants.

Describe the depth to source area.

Describe the potential migration characteristics (e.g., stable, increasing, decreasing) for

the distribution of contaminants.

Geology/Hydrogeology

Review all boring logs, monitoring well construction, and soil sampling data to

understand the following:

Heterogeneity/homogeneity of soils and the lithologic units encountered and the

expected/observed contaminant migration:

o Depth and lateral continuity of any confining units that may impede

contaminant migration

o Depth and lateral continuity of any highly transmissive units that may enhance

contaminant migration

Depth of vadose (unsaturated) zone, capillary fringe, and phreatic (saturated)

zone:

o Note any seasonal groundwater fluctuations and seasonal flow direction

changes (hydraulic gradient).

o Note the depth interval between the vapor source and the ground surface.

o Note the presence of any perched aquifers.

o Note where the groundwater surface intersects the well screen interval or the

presence of submerged screen.

Describe distinct strata (soil type and moisture content, e.g., moist, wet, dry) and the

depth intervals between the vapor source and ground surface.

Describe the depth to groundwater.

Describe groundwater characteristics (e.g., seasonal fluctuation, hydraulic gradient).

Site Characteristics

Estimate the distance from edge of groundwater plume to building.

Determine nearby potential sources.

Estimate the distance from vapor source area to building.

Describe the surface cover between the vapor source area and the potentially impacted

building.

APPENDIX D

DEC Indoor Air Target Levels

D-1

Appendix D: Target Levels for Indoor Air

CAS

Number

Hazardous Substance1 Residential

Indoor Air

(µg/m3)

Residential

Indoor Air

(ppbv)

Commercial

Indoor Air

(µg/m3)

Commercial

Indoor Air

(ppbv)

67-64-1 Acetone 3300 1400 13800 5800

71-43-2 Benzene2 3.1 0.98 16 4.9

111-44-4 Bis(2-chloroethyl)ether 0.074 0.013 0.37 0.064

75-27-4 Bromodichloromethane 1.4 0.21 6.9 1.0

75-25-2 Bromoform 22 2.1 110 11

104-51-8 n-Butylbenzene2

37 6.7 150 28

135-98-8 sec-Butylbenzene2

37 6.7 150 28

98-06-6 tert-Butylbenzene2

37 6.7 150 28

75-15-0 Carbon Disulfide 730 230 3100 990

56-23-5 Carbon Tetrachloride 1.6 0.26 8.2 1.3

108-90-7 Chlorobenzene 52 11 220 48

124-48-1 Chlorodibromomethane 1.0 0.12 5.1 0.60

75-00-3 Chloroethane 29 11 150 56

67-66-3 Chloroform 1.1 0.22 5.3 1.1

95-57-8 2-Chlorophenol 18 3.5 77 15

95-50-1 1,2-Dichlorobenzene 210 35 880 150


106-46-7 1,4-Dichlorobenzene 3.5 0.59 18 3.0

75-71-8 Dichlorodifluoromethane 210 42 880 180

75-34-3 1,1-Dichloroethane 520 130 2200 540

107-06-2 1,2-Dichloroethane 0.94 0.23 4.7 1.2

75-35-4 1,1-Dichloroethylene 0.49 0.12 2.5 0.62

156-59-2 cis-1,2-Dichloroethylene 37 9.2 150 39

156-60-5 trans-1,2-Dichloroethylene 63 16 260 66

78-87-5 1,2-Dichloropropane 1.3 0.27 6.3 1.4

542-75-6 1,3-Dichloropropene 6.1 1.3 31 6.8

100-41-4 Ethylbenzene2

22 5.1 110 26

106-93-4 EDB (1,2-Dibromoethane) 0.041 0.0053 0.20 0.027

50-00-0 Formaldehyde 1.9 1.5 9.4 7.7

118-74-1 Hexachlorobenzene 0.053 0.0045 0.27 0.023

87-68-3 Hexachloro-1,3-butadiene 1.1 0.10 5.6 0.52

77-47-4 Hexachlorocyclopentadiene 0.21 0.019 0.88 0.079

67-72-1 Hexachloroethane 6.1 0.63 31 3.2

302-01-2 Hydrazine 0.0050 0.0038 0.025 0.019

98-82-8 Isopropylbenzene 420 85 1800 360

74-83-9 Methyl Bromide 5.2 1.3 22 5.6

74-87-3 Methyl Chloride 14 6.6 68 33

78-93-3 MEK 5200 1800 21900 7400

108-10-1 MIBK 3100 760 13100 3200

7439-97-6 Mercury (elemental) 0.31 0.038 1.3 0.16

74-95-3 Methylene Bromide 36.5 5.14 150 22

75-09-2 Methylene Chloride 52 15 260 75

D-2

Appendix D: Target Levels for Indoor Air

CAS

Number


Indoor Air

(µg/m3)

Residential

Indoor Air

(ppbv)

Commercial

Indoor Air

(µg/m3)

Commercial

Indoor Air

(ppbv)

90-12-0 1-Methylnaphthalene 14.6 2.51 61 11

91-57-6 2-Methylnaphthalene 14.6 2.51 61 11

1634-04-4 MTBE 47 13 240 66

91-20-3 Naphthalene2

0.72 0.14 3.6 0.69

98-95-3 Nitrobenzene 2.1 0.41 8.8 1.7

62-75-9 n-Nitrosodimethylamine 0.0017 0.00057 0.0088 0.0029

103-65-1 n-Propylbenzene2

37 7.4 150 31

100-42-5 Styrene2

1000 240 4400 1000

79-34-5 1,1,2,2-Tetrachloroethane 0.42 0.061 2.1 0.31

127-18-4 Tetrachloroethylene (PCE) 4.1 0.61 21 3.1

108-88-3 Toluene2

5200 1400 21900 5800

120-82-1 1,2,4-Trichlorobenzene 4.2 0.56 18 2.4

71-55-6 1,1,1-Trichloroethane 2300 420 9600 1800

79-00-5 1,1,2-Trichloroethane 1.5 0.28 7.7 1.4

79-01-6 Trichloroethylene (TCE) 0.22 0.041 1.1 0.21

96-18-4 1,2,3-Trichloropropane 0.012 0.0020 0.061 0.010

76-13-1 Trichlorotrifluoroethane 31300 4100 131000 17200

75-69-4 Trichlorofluoromethane 730 130 3100 550

95-63-6 1,2,4-Trimethylbenzene2

7.3 1.5 31 6.2


7.3 1.5 31 6.2

108-05-4 Vinyl Acetate 210 59 880 250

75-01-4 Vinyl Chloride (Chloroethene) 0.81 0.32 1.1 0.41

1330-20-7 Xylenes (total)2

100.0 24.03 440 100

Notes:


ppbv – parts per billion by volume 1

The chemicals listed here are found in Table B2 of 18 AAC 75.341 and Table C of 18 AAC 75.345 and are volatile

compounds as defined by DEC. If a chemical is not on this list, and not in Table B1 of 18 AAC 75.34 or Table C of

18 AAC 75.345, the chemical has not been evaluated for volatility. Contact the DEC risk assessor to determine if the

chemical is volatile. 2

These chemicals should be investigated as chemicals of potential concern when petroleum is present. If fuel

containing additives (e.g., 1,2-dichloroethane, ethylene dibromide, methyl tert-butyl ether) was spilled, these

chemicals should also be investigated.

APPENDIX E

DEC Shallow Soil Gas Target Levels

E-1

Appendix E: Target Levels for Shallow1 or Subslab Soil Gas

2

CAS

Number


Soil Gas

(µg/m3)

Residential

Soil Gas

(ppbv)

Commercial

Soil Gas

(µg/m3)

Commercial

Soil Gas

(ppbv)

67-64-1 Acetone 32900 13800 138000 58100

71-43-2 Benzene4 31 9.8 160 49

111-44-4 Bis(2-chloroethyl)ether 0.74 0.13 3.7 0.64

75-27-4 Bromodichloromethane 14 2.1 69 10

75-25-2 Bromoform 220 21 1100 110


370 67 1500 280


370 67 1500 280


370 67 1500 280


56-23-5 Carbon Tetrachloride 16 2.6 82 13

108-90-7 Chlorobenzene 520 110 2200 480

124-48-1 Chlorodibromomethane 10 1.2 51 6.0

75-00-3 Chloroethane 290 110 1500 560

67-66-3 Chloroform 11 2.2 53 11

95-57-8 2-Chlorophenol 180 35 770 150



106-46-7 1,4-Dichlorobenzene 35 5.9 180 30


75-34-3 1,1-Dichloroethane 5200 1300 21900 5400

107-06-2 1,2-Dichloroethane 9.4 2.3 47 12

75-35-4 1,1-Dichloroethylene 4.9 1.2 25 6.2

156-59-2 cis-1,2-Dichloroethylene 370 92 1500 390


78-87-5 1,2-Dichloropropane 13 2.7 63 14

542-75-6 1,3-Dichloropropene 61 13 310 68


220 51 1100 260

106-93-4 EDB (1,2-Dibromoethane) 0.41 0.053 2.0 0.27

50-00-0 Formaldehyde 19 15 94 77

118-74-1 Hexachlorobenzene 0.53 0.045 2.7 0.23

87-68-3 Hexachloro-1,3-butadiene 11.1 1.04 56 5.2

77-47-4 Hexachlorocyclopentadiene 2.1 0.19 8.8 0.79

67-72-1 Hexachloroethane 61 6.3 310 32

302-01-2 Hydrazine 0.050 0.038 0.25 0.19


74-83-9 Methyl Bromide 52 13 220 56

74-87-3 Methyl Chloride 140 66 680 330

78-93-3 MEK 52100 17700 219000 74300

108-10-1 MIBK 31300 7600 131000 32100

7439-97-6 Mercury (elemental) 3.1 0.38 13 1.6

74-95-3 Methylene Bromide 370 51 1500 220


90-12-0 1-Methylnaphthalene 150 25 610 110

E-2

Appendix E: Target Levels for Shallow1 or Subslab Soil Gas

2

CAS

Number


Soil Gas

(µg/m3)

Residential

Soil Gas

(ppbv)

Commercial

Soil Gas

(µg/m3)

Commercial

Soil Gas

(ppbv)


1634-04-4 MTBE 470 130 2400 660


7.2 1.4 36 6.9

98-95-3 Nitrobenzene 21 4.1 88 17



370 74 1500 310

100-42-5 Styrene4

10400 2400 43800 10300

79-34-5 1,1,2,2-Tetrachloroethane 4.2 0.61 21 3.1

127-18-4 Tetrachloroethylene (PCE) 41 6.1 210 31

108-88-3 Toluene4

52100 13800 219000 58200

120-82-1 1,2,4-Trichlorobenzene 42 5.6 180 24


79-00-5 1,1,2-Trichloroethane 15 2.8 77 14

79-01-6 Trichloroethylene (TCE) 2.2 0.41 11 2.1

96-18-4 1,2,3-Trichloropropane 0.12 0.020 0.61 0.10




73 15 310 62


73 15 310 62

108-05-4 Vinyl Acetate 2100 590 8800 2500

75-01-4 Vinyl Chloride (Chloroethene) 8.1 3.2 11 4.1


1000 240 4400 1000

Notes:



Shallow soil gas includes soil gas collected from 5 feet or less below the ground surface, or 5 feet or less below a

foundation. 2

Do not rely on target levels when a vapor source is less than 15 feet from the foundation and preferential pathways,

significant openings, or low building air exchange exist. 3








APPENDIX F

DEC Deep Soil Gas Target Levels

F-1

Appendix F: Target Levels for Deep Soil Gas1,2

CAS Number Hazardous Substance3 Residential

Soil Gas

(µg/m3)

Residential

Soil Gas

(ppbv)

Commercial

Soil Gas

(µg/m3)

Commercial

Soil Gas

(ppbv)

67-64-1 Acetone 329000 138000 1380000 581000

71-43-2 Benzene4 310 98 1600 490

111-44-4 Bis(2-chloroethyl)ether 7.4 1.3 37 6.4

75-27-4 Bromodichloromethane 140 21 690 100

75-25-2 Bromoform 2200 210 11000 1100


3700 670 15000 2800


3700 670 15000 2800


3700 670 15000 2800


56-23-5 Carbon Tetrachloride 160 26 820 130

108-90-7 Chlorobenzene 5200 1100 22000 4800

124-48-1 Chlorodibromomethane 100 12 510 60

75-00-3 Chloroethane 2900 1100 15000 5600

67-66-3 Chloroform 110 22 530 110

95-57-8 2-Chlorophenol 1800 350 7700 1500





75-34-3 1,1-Dichloroethane 52000 13000 219000 54000

107-06-2 1,2-Dichloroethane 94 23 470 120

75-35-4 1,1-Dichloroethylene 49 12 250 62

156-59-2 cis-1,2-Dichloroethylene 3700 920 15000 3900


78-87-5 1,2-Dichloropropane 130 27 630 140

542-75-6 1,3-Dichloropropene 610 130 3100 680


2200 510 11000 2600

106-93-4 EDB (1,2-Dibromoethane) 4.1 0.53 20 2.7

50-00-0 Formaldehyde 190 150 940 770

118-74-1 Hexachlorobenzene 5.3 0.45 27 2.3

87-68-3 Hexachloro-1,3-butadiene 111 10.4 560 52

77-47-4 Hexachlorocyclopentadiene 21 1.9 88 7.9

67-72-1 Hexachloroethane 610 63 3100 320

302-01-2 Hydrazine 0.5 0.38 2.5 1.9


74-83-9 Methyl bromide 520 130 2200 560

74-87-3 Methyl chloride 1400 660 6800 3300

78-93-3 MEK 521000 177000 2190000 743000

108-10-1 MIBK 313000 76000 1310000 321000

7439-97-6 Mercury (elemental) 31 3.8 130 16

74-95-3 Methylene Bromide 3700 510 15000 2200



F-2

Appendix F: Target Levels for Deep Soil Gas1,2

CAS Number Hazardous Substance3 Residential

Soil Gas

(µg/m3)

Residential

Soil Gas

(ppbv)

Commercial

Soil Gas

(µg/m3)

Commercial

Soil Gas

(ppbv)


1634-04-4 MTBE 4700 1300 24000 6600


72 14 360 69

98-95-3 Nitrobenzene 210 41 880 170



3700 740 15000 3100

100-42-5 Styrene4

104000 24000 438000 103000

79-34-5 1,1,2,2-Tetrachloroethane 42 6.1 210 31

127-18-4 Tetrachloroethylene (PCE) 410 61 2100 310

108-88-3 Toluene4

521000 138000 2190000 582000

120-82-1 1,2,4-Trichlorobenzene 420 56 1800 240



79-01-6 Trichloroethylene (TCE) 22 4.1 110 21

96-18-4 1,2,3-Trichloropropane 1.2 0.2 6.1 1




730 150 3100 620


730 150 3100 620

108-05-4 Vinyl Acetate 21000 5900 88000 25000

75-01-4 Vinyl chloride (Chloroethene) 81 32 110 41


10000 2400 44000 10000

Notes:



Deep soil gas includes soil gas collected more than 5 feet below the ground surface, or more than 5 feet below a

foundation. 2

Do not rely on target levels when a vapor source is less than 15 feet from the foundation and preferential pathways,

significant openings, or low building air exchange exist. 3








APPENDIX G

DEC Groundwater Target Levels

G-1

Appendix G: Target Levels for Groundwater1

CAS

Number

Hazardous Substance2

Residential

Groundwater Level

(µg/L)

Commercial

Groundwater Level

(µg/L)

67-64-1 Acetone 2030000 8520000

71-43-2 Benzene3 14 69

111-44-4 Bis(2-chloroethyl)ether 110 530

75-27-4 Bromodichloromethane 16 80

75-25-2 Bromoform 1000 5100

104-51-8 n-Butylbenzene3 68 290

135-98-8 sec-Butylbenzene3 48 200

98-06-6 tert-Butylbenzene3 71 300

75-15-0 Carbon Disulfide 1200 5200

56-23-5 Carbon Tetrachloride 1.4 7.2

108-90-7 Chlorobenzene 410 1700

124-48-1 Chlorodibromomethane 32 160

75-00-3 Chloroethane 23000 96500

67-66-3 Chloroform 7.1 36

95-57-8 2-Chlorophenol 39800 167000

95-50-1 1,2-Dichlorobenzene 2700 11200



75-71-8 Dichlorodifluoromethane 15 63

75-34-3 1,1-Dichloroethane 2300 9500

107-06-2 1,2-Dichloroethane 19 98

75-35-4 1,1-Dichloroethylene 0.45 2.3

156-59-2 cis-1,2-Dichloroethylene 220 920

156-60-5 trans-1,2-Dichloroethylene 160 690

78-87-5 1,2-Dichloropropane 11 55

542-75-6 1,3-Dichloropropene 42 210

100-41-4 Ethylbenzene3 69 350

106-93-4 EDB (1,2-Dibromoethane) 1.5 7.5

50-00-0 Formaldehyde 136000 684000

118-74-1 Hexachlorobenzene 0.76 3.8

87-68-3 Hexachloro-1,3-butadiene 2.6 13

77-47-4 Hexachlorocyclopentadiene 0.19 0.80

67-72-1 Hexachloroethane 38 190

302-01-2 Hydrazine 8400 42500

98-82-8 Isopropylbenzene 890 3700

74-83-9 Methyl Bromide 20 86

74-87-3 Methyl Chloride 37 190

78-93-3 MEK 2240000 9400000

108-10-1 MIBK 555000 2330000

74-95-3 Methylene Bromide 1100 4600

75-09-2 Methylene Chloride 390 2000

90-12-0 1-Methylnaphthalene 700 2900

G-2

Appendix G: Target Levels for Groundwater1

CAS

Number

Hazardous Substance2

Residential

Groundwater Level

(µg/L)

Commercial

Groundwater Level

(µg/L)

91-57-6 2-Methylnaphthalene 690 2900

1634-04-4 MTBE 2000 9900

91-20-3 Naphthalene3 40 200

98-95-3 Nitrobenzene 2100 8900

62-75-9 n-Nitrosodimethylamine 23 120

103-65-1 n-Propylbenzene3 68 290

100-42-5 Styrene3 9300 39100

79-34-5 1,1,2,2-Tetrachloroethane 28 140

127-18-4 Tetrachloroethylene (PCE) 5.7 29

108-88-3 Toluene3 19200 80800

120-82-1 1,2,4-Trichlorobenzene 72 300

71-55-6 1,1,1-Trichloroethane 3300 13700

79-00-5 1,1,2-Trichloroethane 45 230

79-01-6 Trichloroethylene (TCE) 0.55 2.8

96-18-4 1,2,3-Trichloropropane 0.87 4.4

76-13-1 Trichlorotrifluoroethane 1500 6100

75-69-4 Trichlorofluoromethane 180 770

95-63-6 1,2,4-Trimethylbenzene3 29 120

108-67-8 1,3,5-Trimethylbenzene3 20 85

108-05-4 Vinyl Acetate 10000 41900

75-01-4 Vinyl Chloride (Chloroethene) 0.71 0.92

1330-20-7 Xylenes (total)3 380 1600

Notes:

µg/L – micrograms per liter 1

Do not rely on target levels when groundwater contamination is less than 5 feet from the foundation or a vapor

source is less than 15 feet from the foundation and preferential pathways, significant openings, or low building air

exchange exist. 2

The chemicals listed here are found in Table B2 of 18 AAC 75.341 and Table C of 18 AAC 75.345 and are

volatile compounds as defined by DEC. If a chemical is not on this list, and not in Table B1 of 18 AAC 75.34 or

Table C of 18 AAC 75.345, the chemical has not been evaluated for volatility. Contact the DEC risk assessor to

determine if the chemical is volatile. 3




APPENDIX H

Background Indoor Air Levels

H-1

Appendix H: Average Background Levels for Indoor Air from Multiple Studies1

(µg/m3)

Hazardous Substance 25

th Percentile 50

th Percentile 75

th Percentile 95

th Percentile

Benzene 1.9 2.5 4.5 17

Carbon Tetrachloride 0.3 0.5 0.7 1.1

Chloroform 0.5 1.1 2.2 6.0

1,1-Dichloroethane <RL <RL <RL <RL

1,2-Dichloroethane <RL <RL <RL 0.2

1,1-Dichloroethylene <RL <RL <RL <RL

cis-1,2-Dichloroethylene <RL <RL <RL <RL

trans-1,2-Dichloroethylene <RL <RL <RL <RL

Ethylbenzene 0.8 2.0 3.0 14

MTBE <RL 1.2 5.7 72

Methylene Chloride 0.42 1.10 3.6 20

Tetrachoroethene (PCE) <RL 0.9 1.8 7.4

Toluene 9 13 27 106

Trichlorotrifluoroethane <RL 0.5 1.1 3.4

1,1,1-Trichloroethene 0.5 1.9 2.7 10.2

Trichloroethene <RL 0.3 0.3 1.6

Vinyl Chloride (Chloroethane) <RL <RL <RL 0.05

Xylenes, m/p- 2.9 5.5 9.4 41

Xylenes, o- 1.4 2.2 3.9 16

Notes:


<RL – less than reporting limit 1Compiled from Dawson and McAlary (2009).

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APPENDIX I

DEC Building Survey and Indoor Air

Sampling Questionnaire

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ALASKA DEPARTMENT OF ENVIRONMENAL CONSERVATION BUILDING INVENTORY AND INDOOR AIR SAMPLING QUESTIONNAIRE

This form should be prepared by a person familiar with indoor air assessments with assistance from a person knowledgeable about the building. Complete this form for each building in which interior samples (e.g., indoor air, crawl space, or subslab soil gas samples) will be collected. Section I of this form should be used to assist in choosing an investigative strategy during workplan development. Section II should be used to assist in identification of complicating factors during a presampling building walkthrough.

Preparer's Name ______________________________________________Date/Time Prepared__________________________ Preparer's Affiliation_________________________________________________Phone No.___________________________ Purpose of Investigation__________________________________________________________________________________ SECTION I: BUILDING INVENTORY 1. OCCUPANT OR BUILDING PERSONNEL:

Interviewed: Y / N Last Name__________________________________________First Name______________________________________ Address____________________________________________________________________________________________ County____________________________________________________________________________________________ Phone No.__________________________________________________________________________________________ Number of Occupants/persons at this location_____________________Age of Occupants__________________________

2. OWNER or LANDLORD: (Check if same as occupant ____)

Interviewed: Y / N Last Name__________________________________________First Name______________________________________ Address____________________________________________________________________________________________ County____________________________________________________________________________________________ Phone No.__________________________________________________________________________________________

3. BUILDING CHARACTERISTICS

Type of Building: (Circle appropriate response) Residential School Commercial/Multi-use Industrial Church Other_______________________________________________

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If the property is residential, type? (Circle appropriate response) Ranch 2-Family 3-Family Raised Ranch Split Level Colonial Cape Cod Contemporary Mobile Home Duplex Apartment House Townhouses/Condos Modular Log Home Other_______________________________________________ If multiple units, how many?____________________ If the property is commercial, type? Business Types(s)________________________________________________________________________________ Does it include residences (i.e., multi-use)? Y / N If yes, how many?_____________________________

Other characteristics: Number of floors______________________________ Building age__________________________________ Is the building insulated? Y / N How air tight? Tight / Average / Not Tight Have occupants noticed chemical odors in the building? Y / N If yes, please describe:________________________________________________________________________________ __________________________________________________________________________________________________

4. AIRFLOW

Use air current tubes, tracer smoke, or knowledge about the building to evaluate airflow patterns and qualitatively describe: Airflow between floors __________________________________________________________________________________________________

__________________________________________________________________________________________________

__________________________________________________________________________________________________

Airflow in building near suspected source __________________________________________________________________________________________________

__________________________________________________________________________________________________

__________________________________________________________________________________________________

Outdoor air infiltration __________________________________________________________________________________________________

__________________________________________________________________________________________________

__________________________________________________________________________________________________

Infiltration into air ducts __________________________________________________________________________________________________

__________________________________________________________________________________________________

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__________________________________________________________________________________________________

5. BASEMENT AND CONSTRUCTION CHARACTERISTICS (Circle all that apply)

a. Above grade construction: wood frame log concrete brick constructed on pilings constructed on pilings with enclosed air space with open air space b. Basement type: full crawlspace slab-on-grade other_____________________________ c. Basement floor: concrete dirt stone other _____________________________ d. Basement floor: unsealed sealed sealed with_____________________________________ e. Foundation walls: poured block stone other _____________________________ f. Foundation walls: unsealed sealed sealed with ____________________________________ g. The basement is: wet damp dry h. The basement is: finished unfinished partially finished i. Sump present? Y / N j. Water in sump? Y / N / not applicable Basement/Lowest level depth below grade_________________________(feet) Identify potential soil vapor entry points and approximate size (e.g., cracks, utility ports, drains) ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 6. HEATING, VENTING and AIR CONDITIONING (Circle all that apply)

Type of heating system(s) used in this building: (Circle all that apply – not primary) Hot air circulation Heat pump Hot water baseboard Space Heaters Stream radiation Radiant floor Electric baseboard Wood stove Outdoor wood boiler Other_________________________ The primary type of fuel used is: Natural Gas Fuel Oil Kerosene Electric Propane Solar Wood Coal Domestic hot water tank fueled by_____________________________________________________________________ Boiler/furnace located in: Basement Outdoors Main Floor Other__________________ Do any of the heating appliances have cold-air intakes? Y / N Type of air conditioning or ventilation used in this building: Central Air Window units Open Windows None

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Commercial HVAC Heat-recovery system Passive air system Are there air distribution ducts present? Y / N

Describe the ventilation system in the building, its condition where visible, and the tightness of duct joints. Indicate the locations of air supply and exhaust points on the floor plan. __________________________________________________________________________________________________ __________________________________________________________________________________________________ __________________________________________________________________________________________________ __________________________________________________________________________________________________ Is there a radon mitigation system for the building/structure? Y / N Date of Installation________________________ Is the system active or passive? Active/Passive

7. OCCUPANCY

Is basement/lowest level occupied? Full-time Occasionally Seldom Almost Never Level General Use of Each Floor (e.g. family room, bedroom, laundry, workshop, storage) Basement _______________________________________________________________________________________ 1st Floor _______________________________________________________________________________________ 2nd Floor _______________________________________________________________________________________ 3rd Floor _______________________________________________________________________________________

8. WATER AND SEWAGE

Water Supply: Public Water Drilled Well Driven Well Dug Well Other__________________ Sewage Disposal: Public Sewer Septic Tank Leach Field Dry Well Other__________________

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9. FLOOR PLANS Draw a plan view sketch of the basement and first floor of the building. Indicate air sampling locations, possible indoor air pollution sources and PID meter readings. If the building does not have a basement, please note. Basement:

First Floor:

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10. OUTDOOR PLOT Draw a sketch of the area surrounding the building being sampled. If applicable, provide information on spill locations, potential air contamination sources (industries, gas stations, repair shops, landfills, etc.), outdoor air sampling location(s) and PID meter readings. Also indicate compass direction, wind direction and speed during sampling, the locations of the well and septic system, if applicable, and a qualifying statement to help locate the site on a topographic map.

I-7

SECTION II: INDOOR AIR SAMPLING QUESTIONNAIRE This section should be completed during a presampling walkthrough. If indoor air sources of COCs are identified and removed, consider ventilating the building prior to sampling. However, ventilation and heating systems should be operating normally for 24 hours prior to sampling.

a) 1. FACTORS THAT MAY INFLUENCE INDOOR AIR QUALITY

Is there an attached garage? Y / N Does the garage have a separate heating unit? Y / N / NA Are petroleum-powered machines or vehicles Y / N /NA stored in the garage (e.g., lawnmower, ATV, car) Please specify____________________________________ Has the building ever had a fire? Y / N When?___________________________________ Is a kerosene or unvented gas space heater present? Y / N Where?__________________________________ Is there a workshop or hobby/craft area? Y / N Where & Type_____________________________ Is there smoking in the building? Y / N How frequently?___________________________

Has painting/staining been done in the last 6 months? Y / N Where & When?___________________________

Is there new carpet, drapes or other textiles? Y / N Where & When?___________________________ Is there a kitchen exhaust fan? Y / N If yes, where vented?_______________________

Is there a bathroom exhaust fan? Y / N If yes, where vented?_______________________ Is there a clothes dryer? Y / N If yes, is it vented outside? Y / N

Are cleaning products, cosmetic products, or pesticides used that could interfere with indoor air sampling? Y / N If yes, please describe________________________________________________________________________________ __________________________________________________________________________________________________ __________________________________________________________________________________________________ Do any of the building occupants use solvents at work? Y / N (e.g., chemical manufacturing or laboratory, auto mechanic or auto body shop, painting, fuel oil delivery, boiler mechanic, pesticide application, cosmetologist

If yes, what types of solvents are used?___________________________________________________________________ If yes, are their clothes washed at work? Y / N

Do any of the building occupants regularly use or work at a dry-cleaning service? (Circle appropriate response)

Yes, use dry-cleaning regularly (weekly) No Yes, use dry-cleaning infrequently (monthly or less) Unknown Yes, work at a dry-cleaning services

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2. PRODUCT INVENTORY FORM (For use during building walkthrough)

Make & Model of field instrument used________________________________________________________________ List specific products found in the residence that have the potential to affect indoor air quality:

Location

Product Description Site (units)

Condition* Chemical Ingredients Field Instrument Reading (units)

Photo ** Y / N

* Describe the condition of the product containers as Unopened (UO), Used (U), or Deteriorated (D) ** Photographs of the front and back of product containers can replace the handwritten list of chemical ingredients. However, the photographs must be of

good quality and ingredient labels must be legible. This form modified from: ITRC (Interstate Technology & Regulatory Council). 2007. Vapor Intrusion Pathway: A Practical Guideline. VI-1. Washington, D.C.: Interstate Technology & Regulatory Council, Vapor Intrusion Team. www.itrcweb.org.

The Alaska Department of Environmental Conservation’s Contaminated Sites Program protects human health and the environment by managing the cleanup of contaminated soil and groundwater in Alaska. For more information, please contact our staff at the Contaminated Site program closest to you:

Juneau: 907-465-5390 / Anchorage: 907-269-7503 Fairbanks: 907-451-2153 / Kenai: 907-262-5210

APPENDIX M RESPONSE TO COMMENTS

THIS APPENDIX CONTAINS INFORMATION RELATED TO NATIONAL SECURITY AND

SHOULD NOT BE RELEASED TO THE PUBLIC

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