FIFTH FIVE-YEAR REVIEW REPORT FOR ARSENIC TRIOXIDE SUPERFUND SITE

RICHLAND, RANSOM AND SARGENT COUNTIES, NORTH DAKOTA

Prepared by

U.S. Environmental Protection Agency Region 8

Betsy Smidinger Assistant Regional Administrator Office of Ecosystems Protection

and Remediation

Denver, Colorado

Date

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Table of Contents LIST OF ABBREVIATIONS & ACRONYMS ....................................................................................................... iii I. INTRODUCTION...................................................................................................................................................1

Site Background .....................................................................................................................................................1 FIVE-YEAR REVIEW SUMMARY FORM ........................................................................................................4

II. RESPONSE ACTION SUMMARY ......................................................................................................................4 Basis for Taking Action .........................................................................................................................................4 Response Actions ...................................................................................................................................................5 Status of Implementation .......................................................................................................................................6 Systems Operations/Operation & Maintenance (O&M) ........................................................................................8

III. PROGRESS SINCE THE PREVIOUS REVIEW ................................................................................................9 IV. FIVE-YEAR REVIEW PROCESS .................................................................................................................... 10

Community Notification, Involvement & Site Interviews ................................................................................... 10 Data Review ......................................................................................................................................................... 11 Site Inspection ...................................................................................................................................................... 11

V. TECHNICAL ASSESSMENT ............................................................................................................................ 12 QUESTION A: Is the remedy functioning as intended by the decision documents? ......................................... 12 QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels and RAO used at the time of the remedy selection still valid? ................................................................................................................................. 12 QUESTION C: Has any other information come to light that could call into question the protectiveness of the remedy? ................................................................................................................................................................ 13

VI. ISSUES/RECOMMENDATIONS ..................................................................................................................... 14 OTHER FINDINGS ............................................................................................................................................. 14

VII. PROTECTIVENESS STATEMENT ................................................................................................................ 14 VIII. NEXT REVIEW .......................................................................................................................................... 15 APPENDIX A – REFERENCE LIST ................................................................................................................... A-1 APPENDIX B – SITE CHRONOLOGY ............................................................................................................... B-1 APPENDIX C – NDDOH CORRESPONDENCE, SITE FACT SHEET AND QUARTERLY REPORTING ... C-1 APPENDIX D – JULY 20, 2018 PRESS NOTICE .............................................................................................. D-1 APPENDIX E – INTERVIEWS ............................................................................................................................ E-1 APPENDIX F – DATA REVIEW ......................................................................................................................... F-1 APPENDIX G – SITE INSPECTION CHECKLIST ............................................................................................ G-1 APPENDIX H – SITE INSPECTION PHOTOS .................................................................................................. H-1

Tables Table 1: Summary of OU1 and OU2 Remedy Components ......................................................................................5 Table 2: Summary of Planned and/or Implemented Institutional Controls (ICs) .......................................................8 Table 3: Protectiveness Determinations/Statements from the 2013 FYR Report ......................................................9 Table 4: Status of Recommendations for OU1 from the 2013 FYR Report ............................................................ 10 Table 5: Summary of Annual Arsenic Concentrations in SEWUD-East Treated Water ......................................... 11 Table B-1: Site Chronology .................................................................................................................................... B-1 Table B-2: Summary of OU1 Remedy Construction Activities Post Site Deletion ............................................... B-2 Table B-3: Summary of OU2 Remedy Construction Activities ............................................................................. B-3 Table F-1: April 2014 Laboratory Results for Treated Water for SEWUD-East ................................................... F-1 Table F-2: February 2015 Laboratory Results for Treated Water for SEWUD-East ............................................. F-2 Table F-3: January 2016 Laboratory Results for Treated Water for SEWUD-East ............................................... F-3

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Table F-4: January 2017 Laboratory Results for Treated Water for SEWUD-East ............................................... F-4 Table F-5: January 2018 Laboratory Results for Treated Water for SEWUD-East ............................................... F-5

Figures Figure 1: Site Vicinity ................................................................................................................................................2 Figure 2: Detailed Site Map .......................................................................................................................................3

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LIST OF ABBREVIATIONS & ACRONYMS

ARAR Applicable or Relevant and Appropriate Requirement ARRA American Recovery and Reinvestment Act CCR Consumer Confidence Report CERCLA Comprehensive Environmental Response, Compensation, and Liability Act CFR Code of Federal Regulations EPA United States Environmental Protection Agency ESD Explanation of Significant Differences FS Feasibility Study FYR Five-Year Review IC Institutional Control MCL Maximum Contaminant Level µg/L Micrograms per Liter mg/kg/day Milligrams per Kilogram per Day NCP National Oil and Hazardous Substances Pollution Contingency Plan NDDoH North Dakota Department of Health NPL National Priorities List NRC National Research Council O&M Operation and Maintenance OU Operable Unit RAO Remedial Action Objective RI Remedial Investigation ROD Record of Decision RPM Remedial Project Manager SCADA Supervisory Control and Data Acquisition SDWA Safe Drinking Water Act SEWUD Southeast Water Users District SWC State Water Commission UU/UE Unlimited Use/Unrestricted Exposure

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I. INTRODUCTION The purpose of a five-year review (FYR) is to evaluate the implementation and performance of a remedy to determine if the remedy is and will continue to be protective of human health and the environment. The methods, findings and conclusions of reviews are documented in FYR reports such as this one. In addition, FYR reports identify issues found during the review, if any, and document recommendations to address them. The U.S. Environmental Protection Agency (EPA) is preparing this FYR pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Section 121, consistent with the National Contingency Plan (NCP) (40 Code of Federal Regulations or CFR, Section 300.430(f)(4)(ii)), and considering EPA policy. This is the fifth FYR for the Arsenic Trioxide Superfund site (the Site). The triggering action for this policy review is the completion date of the previous FYR. The first Record of Decision (ROD) was signed on September 26, 1986, prior to the effective date of the Superfund Amendments and Reauthorization Act (SARA) of October 17, 1986, resulting in this being a policy review. The FYR has been prepared due to the fact that hazardous substances, pollutants or contaminants remain at the Site above levels that allow for unlimited use and unrestricted exposure (UU/UE). The Site consists of two operable units (OUs). This FYR addresses both OUs. OU1 addresses contaminated groundwater treated at the Richland Rural Water Treatment System. OU2 initially addressed contaminated groundwater at the Lidgerwood and Wyndmere treatment plants; however, later these plants were no longer used and the cities supplied by them became part of OU1. EPA remedial project manager (RPM) Frances L. Costanzi led the FYR. The North Dakota Department of Health (NDDoH) is the lead agency at the Site, with EPA as the support agency. Carl Anderson is the project manager representing NDDoH (State). Treat Suomi and Claire Marcussen from Skeo provided EPA contractor support. The review began in October 2017. Documents used to prepare this FYR are summarized in Appendix A. Appendix B includes the detailed site chronology. Site Background The Site is located in southeastern North Dakota. It covers 26 townships (about 940 square miles) and encompasses portions of Richland, Ransom and Sargent counties (Figure 1). The site area is sparsely populated farmland and prairie land with a few small towns, including Lidgerwood, Wyndmere, Milnor and Hankinson. The historical use of arsenic-based grasshopper bait as well as naturally occurring sources of arsenic resulted in contamination of groundwater in the communities of Hankinson, Lidgerwood, Wyndmere and Milnor, as well as at private homes and farms in unincorporated areas. Groundwater aquifer systems within the Site include the shallow groundwater system and the deep bedrock system. The shallow system consists of several named glacial drift aquifers present within the site boundary to include the Sheyenne Delta, Hankinson, Spiritwood, Milnor Channel, Brightwood, and Gwinner aquifers. The bedrock aquifer is present with the Dakota Group which includes several formations and is generally referred to as the Dakota Aquifer. Arsenic contamination is limited to the shallow system, which is used as a drinking water source in the region and for agricultural purposes, including irrigation and livestock watering. The Site is currently serviced by the Southeast Water Users District’s (SEWUD’s) eastern water treatment plant (SEWUD-East). It draws water from the Hankinson aquifer within the shallow system. SEWUD-East treats the water prior to distribution to the cities of Lidgerwood, Wyndmere, Milnor and Hankinson, and surrounding areas (Figure 2).

Surface waters in the vicinity of the Site consist of the Wild Rice River and its tributaries, and area sloughs and prairie potholes. These surface water bodies recharge the aquifer during the spring and summer.

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Figure 1: Site Vicinity

Disclaimer: This map and any boundary lines within the map are approximate and subject to change. The map is not a survey. The map is for informational purposes only regarding EPA’s response actions at the Site.

[::::::::J__ __ __:\-r---1,r-, NuJorth Dakota

0

Sources: Esri, Delorme, AND, Tele Atlas, First American, UNEP-WCMC, 2009 Remedial Action Report - Rural Water System Expansion - Segment 3 and USGS.

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Arsenic Trioxide Superfund Site

10

~Skeo· 0 NORTH

Ransom, Richland and Sargent Counties, North Dakota

Ransom County

20 Miles

Legend

c:]Approximate Site Boundary

North Dakota County Boundary

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Figure 2: Detailed Site Map

Disclaimer: This map and any boundary lines within the map are approximate and subject to change. The map is not a survey. The map is for informational purposes only regarding EPA’s response actions at the Site.

0 5 10 20 Miles

Sources: Sources: Esri, Delorme, AND, Tele Atlas, First American, UNEP-WCMC, Digita/Gfobe, GeoEye, Earthstar Geographies, CNES/Airbus OS, USDA, USGS, AEX, Getmapping, Aerogrid, /GN, /GP, swisstopo, 2009 Remedial Action Report - Rural Water System Expansion - Segment 3 and the GIS User Community.

Arsenic Trioxide Superfund Site Ransom, Richland and Sargent Counties, North Dakota

Legend

@ SEWUD District Office • Approximate Site Boundary

North Dakota County Boundary

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FIVE-YEAR REVIEW SUMMARY FORM

II. RESPONSE ACTION SUMMARY Basis for Taking Action In 1979, NDDoH identified elevated levels of arsenic at the water treatment systems in Lidgerwood and Wyndmere during routine water quality monitoring of municipal water. The levels exceeded the federal drinking water standard or maximum contaminant level (MCL) at the time of 50 micrograms per liter (µg/L). Additional monitoring detected more widespread occurrence of arsenic within groundwater in surrounding rural areas. Based on a remedial investigation/feasibility study (RI/FS) conducted by NDDoH from 1982 to 1986 and overseen by EPA, the agencies concluded that the most likely exposure pathway of arsenic is from human ingestion of groundwater and locally produced meat or dairy products because the livestock may have been exposed to high-arsenic drinking water. Exposure to soil did not pose a concern as soil sampling did not detect any residual sources of arsenic. The RI demonstrated that grasses and woody-stemmed bushes grown in arsenic-impacted soil are not expected to raise arsenic levels in grazing animals.

SITE IDENTIFICATION

Site Name: Arsenic Trioxide

EPA ID: NDD980716963

Region: 8 State: North Dakota

City/County: Hankinson, Lidgerwood, Wyndmere and Milnor Cities/Richland, Ransom and Sargent

SITE STATUS

NPL Status: Deleted

Multiple OUs? Yes

Has the site achieved construction completion? Yes

REVIEW STATUS

Lead agency: EPA

Author name: Frances L. Costanzi, Claire Marcussen and Treat Suomi

Author affiliation: EPA Region 8 and Skeo

Review period: 10/1/2017 - 6/29/2018

Date of site inspection: 5/22/2018

Type of review: Policy

Review number: 5

Triggering action date: 9/30/2013

Due date (five years after triggering action date): 9/30/2018

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Response Actions EPA proposed the Site for listing on the Superfund Program’s National Priorities List (NPL) in December 1982. EPA listed the Site on the NPL in September 1983. Originally, EPA designated the Site as a single OU, which was the Richland Rural Water Treatment System (now SEWUD). In 1986, the existing Lidgerwood and Wyndmere water treatment systems were effective in the removal of arsenic. However, after EPA signed the Site’s 1986 Record of Decision (ROD), the cities of Lidgerwood and Wyndmere requested consideration of their respective water treatment plant expansions as part of the Site’s overall remedial action so that expansion costs could be reimbursed. Therefore, EPA issued a ROD Amendment in 1988. EPA designated the Richland Rural Water Treatment System as OU1 and the Lidgerwood and Wyndmere treatment plants as OU2. Due to increased demand and declining performance for arsenic removal at the Wyndmere and Lidgerwood water treatment plants, the cities of Lidgerwood and Wyndmere were connected to SEWUD-East and became part of OU1 in 2006 and 2009, respectively. The remedial action objective (RAO) established for the Site was to reduce exposure to arsenic-contaminated groundwater. The 1986 ROD required remediation of groundwater to the background concentration of 25 µg/L. EPA changed this cleanup goal to 10 µg/L in a 2007 Explanation of Significant Differences (ESD) to reflect the revised federal MCL. Table 1 provides a summary of the remedy components as described in the ROD, ROD Amendment and ESDs. The primary remedial components included the expansion of the SEWUD-East (OU1), and the Lidgerwood and Wyndmere water treatment plants (OU2) and their associated distribution systems between 1986 and 1992. The multiple ESDs for OU1were issued to address additional phases of expansion of the SEWUD water treatment plant to accommodate the increased demand due to the change in the arsenic MCL from 50 µg/L to 10 µg/L. In addition, the 2009 ESD required the need for implementation of institutional controls to protect future users of domestic groundwater wells in the Site area. Table 1: Summary of OU1 and OU2 Remedy Components

OU Remedial Components Decision Document OU1

Expansion of SEWUD-East and its associated distribution system to provide safe drinking water to rural households where arsenic exceeded the MCL at that time of 50 µg/L.

1986 ROD

Monitoring of the treatment plants, glacial aquifer systems and private wells. 1986 ROD

Implementation of multiple layers of institutional controls to encourage public participation in the project and restrict private water supply well use. OU2 later became part of OU1 such that the institutional controls applied to the entire Site.

1986 ROD 2009 ESD

Increased capacity of the SEWUD-East water treatment plant and wells added to meet the increased water demands of the Wyndmere and Hankinson communities.

September 2007 ESD

Provision of bottled water to interested rural households within the site boundary whose groundwater wells contained arsenic levels above the 10 µg/L MCL and expansion of the SEWUD water treat plant and production wells to meet the increased water demands of the Wyndmere and Hankinson communities

September 2007 ESD October 2007 ESD

Connection of about 60 rural users to the SEWUD-East water supply system near Wyndmere and the Lake Elsie area for residents whose groundwater wells contained arsenic levels that exceeded or were equal to the MCL of 10 µg/L.

2008 ESD

Connection of qualified rural households to the SEWUD system (about 330 rural households) and expansion of the SEWUD treatment plant and system to accommodate the increased demand.

2009 ESD

OU2 Reimbursement from the Superfund program to the Lidgerwood city government for remedy-associated costs associated with construction of its water treatment plant.

1988 ROD Amendment

Modification of the Lidgerwood water treatment plant. 1988 ROD Amendment Expansion of the Wyndmere water treatment plant to increase its storage capacity with a 50,000-gallon potable water storage reservoir and related minor adjustments and modifications to the existing plant.

1988 ROD Amendment

Construct a potable water reservoir and distribution system in the City of Milnor 1992 ESD

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Status of Implementation OU1 – SEWUD-East

NDDoH completed the remedial design between March 1987 and June 1989. The effort included the application of a precipitation technology to co-precipitate arsenic into an insoluble solid. The insoluble arsenic precipitant is then removed from the liquid phase by filtration. Remedial construction occurred in two phases. Phase 1, to expand SEWUD-East and the distribution system, began in July 1990. Phase 1 included installation of about 300 miles of water distribution pipeline, seven additional water storage reservoirs, installation of three additional water supply wells and the doubling of the size of the treatment plant. Phase 2 began in September 1991 and ended in June 1993. The project added Milnor to the distribution system. During the summer of 1992, remedial actions included the connection of about 300 homes and businesses to a new 135,000-gallon drinking water reservoir and distribution system. Both phases of remedial construction activities finished in June 1993. Following the completion of Phase 2 activities, the Richland Rural Water Treatment System took over operation and maintenance of the treatment system. EPA documented the completion of work in a Final Close-Out Report, dated June 30, 1993, and deleted the Site from the NPL on July 5, 1996.

EPA revised the arsenic MCL from 50 µg/L to 10 µg/L in 2001. In June 2003, EPA conducted an extensive rural user well sampling program to determine if rural users in the 26 townships were drinking water with arsenic concentrations over the new MCL. Based on the sampling, EPA and NDDoH determined that the remedy needed to be expanded using a segmented design and construction approach, with the scope of work for each segment dictated by the amount of available funding. In the interim, EPA and NDDoH offered bottled water to interested rural households located within the site boundary whose groundwater wells contained arsenic levels above the 10 µg/L MCL. The expanded remedy included six new segments – 1, 2, 3, 4, 4a and 5. NDDoH completed the remedial design for the expansion of SEWUD-East between September 2004 and March 2010. NDDoH entered into a contract with SEWUD and SEWUD conducted the design and construction under oversight from NDDoH and EPA. SEWUD completed remedy construction in 2011. Segment 1 included installing and extending new water lines from existing lines to new underground reservoirs and construction of pump facilities for the cities of Wyndmere and Hankinson. In addition, modifications were made to SEWUD-East Reservoir B. Segment 2 included expansion of the well field and upgrades to the treatment train of the SEWUD-East water treatment plant. Segment 3 included connection of rural households from the cities of Wyndmere and Hankinson to the SEWUD-East distribution system. Segment 4 and 4a included connection of rural users to SEWUD-East in the cities of Cayuga and Geneseo and upgrading of water supply reservoirs. Segment 5 included well field expansion to provide treated water to the city of Lidgerwood and other users, expansion of system capacity through construction of new reservoirs, installation of an emergency generator to diminish service interruptions, additional upgrades to the SEWUD-East treatment facility, and installation of a geothermal system to lessen the reliance of SEWUD’s headquarters facility in Mantador on non-renewable energy sources. Appendix B provides additional information on remedy implementation (Table B-3). OU2 – Cities of Lidgerwood and Wyndmere Primary OU2 remediation activities initially consisted of the expansion of the water treatment buildings in the cities of Lidgerwood and Wyndmere. Due to the decline in both city’s system performance, both cities became part of OU1 once they were connected to the SEWUD system. NDDoH connected the cities of Wyndmere and Lidgerwood to the SEWUD system in 2006 and 2010, respectively. Appendix B provides a detailed summary of the construction activities completed as part of the expansion of water treatment facilities in the cities of Lidgerwood and Wyndmere prior to their eventual connection to SEWUD-East as part of OU1 (Table B-3).

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Institutional Controls Review The 2009 OU1 ESD identified institutional controls for the Site. They included: 1) preparation of annual Consumer Confidence Reports (CCRs); 2) completion of well searches by the NDDoH of the State Water Commission’s (SWC) database for new wells drilled within the Site; 3) provision of a fact sheet to property owners within the Site’s boundaries when new wells are drilled; 4) NDDoH working with the State Board of Water Well Contractors to provide information, including the fact sheet, to North Dakota-certified well drillers regarding the arsenic-contaminated groundwater; and 5) posting of the site fact sheet on EPA Region 8’s website and NDDoH’s Groundwater Protection website. Table 2 provides a summary of the institutional controls and their implementation dates. The informational institutional controls have been implemented to meeting the institutional control objective of educating, informing and notifying residents and well drillers that shallow groundwater within the Site may contain arsenic levels above Safe Drinking Water Act (SDWA) MCLs and that there are potential risks of consuming arsenic-contaminated water. The primary informational control is a fact sheet that EPA and NDDoH prepared in 2012 and is shared with the general public through a variety of mechanisms. The fact sheet provides information on the potential health effects of arsenic exposure in drinking water and information on how to limit exposure. It also informs owners of existing groundwater wells that they should determine if their water has been tested for arsenic levels and that NDDoH maintains records of previously tested wells and provides results to owners at no charge.1 There is no requirement that a new potable well be sampled prior to use to ensure that the MCL for arsenic is not exceeded. For existing wells that have not been tested, the fact sheet provides additional information on how to get the well tested. The fact sheet also lists several options for owners of existing potable wells to consider should arsenic concentrations exceed the MCL. The options include: 1) household point-of-use treatment – water purification units installed at owners’ homes; 2) connection to the public water supply; and 3) using bottled drinking water. The well owner is responsible for the costs related to these options. The 2013 FYR Report recommended updating the 2012 fact sheet to include information regarding the uses of rural wells for watering livestock and poultry. EPA is currently working with NDDoH to update the fact sheet to address this issue. Once finalized, it will be included in the annual CCR distribution and posted on the SEWUD, NDDoH and EPA websites. The fact sheet is included with the annual mailing of the water quality report to SEWUD members, as summarized in the CCRs. The CCR reports and facts sheets are mailed to rural water subscribers in May of each year. The fact sheet is also posted on the SEWUD and NDDoH websites. EPA Region 8’s website also provides links to NDDoH and SEWUD websites.2,3 NDDoH does not require permits for potable wells to be drilled on private property. The NDDoH provides the Fact Sheet to the State Board of Water Well Contractors which includes the fact sheets to licensed well drillers each December. In addition, the NDDoH conducts on a quarterly basis well searches utilizing queries within SWC’s database to identify wells installed within the site boundary. Starting in July 2018, NDDoH sends the results of the quarterly database search to EPA along with a list of the new wells drilled and the well type (e.g., domestic, municipal, for livestock). NDDoH sends letters and fact sheets to well owners following completion of new wells. An example letter is included in Appendix C along with the fact sheet and also a copy of the July 2018 quarterly report. In addition, SWC sends out drilling contractor license renewals each December, at which time fact sheets are included in the renewal notices. NDDoH provides the fact sheet to SWC prior to its December mailings.

1 The NDDoH only has well sample data for residents that participated in the Site’s well sampling project or those that may participate in NDDoH’s ambient groundwater monitoring project. Private well owners who have had their wells tested outside of these two projects are not required to send data to the NDDoH. Consequently, the NDDoH may not have data available even though the well has been sampled in the past. 2 https://seh2o.com/pdf/arsenic_trioxide_factsheet.pdf 3 https://deq.nd.gov/Publications/WQ/1_GW/arsenic/ArsenicTrioxideSuperfundSiteFactSheet.pdf

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County officials do not issue building permits or require permits for new well installations for construction projects in the 26 townships included in the Site. Instead, NDDoH furnishes fact sheets to the North Dakota Township Officers Association, which oversees townships within the Site, for distribution to each individual township officer. The township officer uses the fact sheets in support of the review of all building projects within a particular township by the Board of Township Supervisors. Appendix C includes an example of NDDoH correspondence documenting the distribution of information to various agencies.

Table 2: Summary of Planned and/or Implemented Institutional Controls (ICs) Media That

Do Not Support

UU/UE Based on Current Conditions

ICs Needed

ICs Called for in the Decision

Documents

Impacted Parcel(s)

IC Objective

Title of IC Instrument Implemented and Date (or planned)

Groundwater Yes Yes Site

Restricting or prohibiting domestic use of water from the shallow aquifer.

Nonea

Educate, inform and notify residents and well drillers that shallow groundwater within the Site may contain arsenic levels above SDWA MCLs and that there are potential risks of consuming arsenic-contaminated water.

9/5/2013 • EPA and NDDoH prepared a fact

sheet and posted it on their websites. • SEWUD includes the fact sheet in

annual water quality reporting to its members.

• NDDoH provided the fact sheet to the SWC.

• NDDoH provided the fact sheet to the Board of Water Well Contractors and North Dakota-certified well drillers.

• NDDoH informed local government officials to include a notification to owners obtaining building permits.

• NDDoH and EPA continue to work with SEWUD to discuss various options for expanding its informational outreach to non-members in the 26 townships within the Site.

Notes: a. NDDoH did not designate the Site as a groundwater protected area because of the high spatial variability in the

distribution of arsenic exceeding the MCL of 10 µg/L. Establishing the entire Site as a “protected area” was considered. It was determined to be infeasible because it would prohibit the installation of wells in areas where arsenic in groundwater is below the arsenic MCL.

Systems Operations/Operation & Maintenance (O&M) As described in the Site’s decision documents, each respective locality assumed long-term water treatment plant O&M responsibilities. Because the cities of Lidgerwood and Wyndmere were connected to the SEWUD-East treatment plant, these two cities are no longer responsible for treatment plant O&M activities. SEWUD assumed responsibility for O&M of the SEWUD-East treatment plant in July 1993. This responsibility is ongoing. Primary activities associated with O&M for the treatment and distribution systems include:

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• Water supply well O&M. • Routine treatment plant process monitoring and quality control. • Distribution system O&M. • Maintenance of chemical delivery lines and filtration units. • Water quality reporting to NDDoH.

The above activities are conducted according to the Site’s 2010 O&M Plan; no deviations from these activities were noted during the site inspection conducted on May 22, 2018.

According to the Site’s 2009 ESD, NDDoH is responsible for overseeing remedy O&M and implementation of institutional controls. Further, according to the 2009 ESD, EPA is not responsible for future improvements to the public water system, barring changes to the protectiveness of the remedy. EPA provides oversight and prepares the FYR Reports. III. PROGRESS SINCE THE PREVIOUS REVIEW This section includes the protectiveness determinations and statements from the previous FYR (Table 3) as well as the recommendations from the previous FYR for OU1 and the status of those recommendations (Table 4). The previous FYR did not identify any recommendations for OU2 because OU2 has been assumed by OU1.

Table 3: Protectiveness Determinations/Statements from the 2013 FYR Report

OU # Protectiveness Determination Protectiveness Statement

1 Short-term Protective The remedy at OU1 currently protects human health and the environment because the SEWUD-East water treatment plant has been upgraded and expanded to provide rural users, formerly on privately owned, impacted wells, with potable water that meets the arsenic MCL. However, in order for the remedy to be protective in the long term, treated groundwater should be monitored on a more frequent basis, a summary of institutional control activities and results should be submitted to EPA on a regular basis, and the Site fact sheet should be updated to discuss watering of livestock and poultry.

2 Protective The remedy at OU2 is protective of human health and the environment. Rural users who had relied on the Wyndmere and Lidgerwood water treatment plants are now connected to the SEWUD-East water treatment plant.

Sitewide Short-term Protective Because the remedial actions at OU1 are protective in the short term, the Site is protective of human health and the environment in the short term. However, in order for the remedy to be protective in the long term, treated groundwater should be monitored on a more frequent basis, a summary of institutional control activities and results should be submitted to EPA on a regular basis, and the Site fact sheet should be updated to discuss watering of livestock and poultry.

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Table 4: Status of Recommendations for OU1 from the 2013 FYR Report

Issue Recommendations Current Status

Current Implementation Status Description

Completion Date (if

applicable) SEWUD-East water treatment plant only monitors arsenic in treated water every two years.

Monitor arsenic concentrations in treated water on a more frequent basis to ensure levels are below the MCL for arsenic.

Completed SEWUD collects samples for arsenic analysis or treated

groundwater on an annual basis.

4/14/2014

NDDoH has not provided EPA with regular updates to demonstrate that informational institutional controls are adequate for achieving site RAOs.

Provide EPA with information summarizing activities related to ensuring the adequacy of informational institutional controls on a quarterly basis.

Completed NDDoH and EPA have agreed upon a quarterly report format and

NDDoH has begun submitting these reports in July 2018

7/2/2018

The current fact sheet does not address uses of rural wells for watering livestock and poultry.

Revise the fact sheet to address watering of livestock and poultry.

Ongoing NDDoH is working with EPA to update the fact sheet to include the

uses of rural wells for watering livestock and poultry.

NA

IV. FIVE-YEAR REVIEW PROCESS Community Notification, Involvement & Site Interviews A public notice was made available by a newspaper posting in The Daily News on 7/20/2018, stating that the FYR was underway and inviting the public to submit any comments to EPA (Appendix D). The results of the review and the report will be made available at the Site’s designated information repository, located at the Southeast Water Users District (206 Main Street, Mantador, North Dakota 58058). Upon completion of the FYR, EPA will place a public notice in The Daily News to announce the availability of the final FYR Report in the Site’s information repository. The FYR Report will also be available on EPA’s website. During the FYR process, interviews were conducted to document any perceived problems or successes with the remedy that has been implemented to date. The results of these interviews are summarized below. Appendix E provides the complete interviews. Carl Anderson with NDDoH indicated that the project has provided qualified rural residents within the site boundary with the opportunity to obtain a safe source of drinking water by providing rural water supplied by SEWUD. Mr. Anderson stated that the remedy was successful at meeting the objectives of the project, which required a cooperative effort between state and federal agencies, SEWUD, and rural residents. He is not aware of any complaints or inquiries over the past five years related to the Site from residents. His department continues to conduct searches for new wells installed within the site boundary and provides owners of new water supply wells with a letter discussing the project and a copy of the fact sheet. He also is looking at additional ways to make arsenic information available to the public with maps and data available on the NDDoH website. Steve Hansen is the general manager of SEWUD. Mr. Hansen indicated that, overall, the project went very well; SEWUD was able to provide quality drinking water to many rural users as well as two cities. He believes the contractors did a good job with the cleanup and they make improvements to the existing infrastructure to ensure it continues to work well. Mr. Hansen indicated that the remedy is working as intended with no problems and that arsenic concentrations continue to be maintained below the MCL in treated water. He also indicated that no

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unexpected O&M difficulties have occurred. Recent O&M efficiencies include the addition of more energy-efficient pumps and variable frequency drives installed on the pumps, which reduces electricity usage. Brian Bergantine, P.E., is the operations manager for O&M contractor AE2S and oversees O&M activities for the project on behalf of SEWUD. Mr. Bergantine indicated that the selected remedy is operating and functioning well, providing users with good-quality water from SEWUD, including the cities of Hankinson and Wyndmere. His assessment of the current performance of the remedy is that it is doing an excellent job of removal of arsenic without any real issues. In fact, SEWUD recently took third place at the National Rural Water Conference for its drinking water quality. Mr. Bergantine indicated that that there have not been any significant changes to or problems with ongoing O&M activities. He indicated that SEWUD continues to make upgrades and improvements to its system through Supervisory Control and Data Acquisition (SCADA) system enhancements to be more efficient in its electrical and chemical usage. The SCADA system allows more accuracy on dosage and variable frequency drives have aligned system output with demand, resulting in lower electrical costs. Data Review The data used for this FYR are those data collected in support of the CCRs specifically for SEWUD-East water treatment plant, as this plant services the Site (Appendix F). Arsenic concentrations in the treated water samples are listed in Table 5. Copies of the laboratory data are included in Appendix F. The arsenic results in treated water from SEWUD-East demonstrate that the treatment plant consistently treats water to meet the SDWA MCL of 10 µg/L for arsenic. Table 5: Summary of Annual Arsenic Concentrations in SEWUD-East Treated Water

Year Arsenic Concentration (µg/L) 2014 8.50

2015 7.00 2016 8.00 2017 8.00 2018 6.00

Source: Annual laboratory results provided by SEWUD. Site Inspection The site inspection took place on 5/22/2018. In attendance were Frances Costanzi (EPA RPM), Carl Anderson (NDDoH), Steve Hansen (SEWUD), and Treat Suomi and Claire Marcussen (Skeo). The purpose of the inspection was to assess the protectiveness of the remedy. The site inspection checklist and photographs are provided in Appendices G and H, respectively. The site inspection began in a conference room at SEWUD, where Ms. Costanzi provided an overview of the status of the Site and summarized the overall objectives of the FYR process. Mr. Hansen provided an overview of the routine O&M conducted at the Site along with updates regarding expansion of reservoirs to increase system capacity. Mr. Andersen provided an overview of the current informational institutional controls in place. Following the meeting, Mr. Hansen led a tour of the Site, beginning with the geothermal unit and associated emergency backup generator at the SEWUD building. Site inspection participants then toured the SEWUD-East water treatment plant, viewing the series of water filters as well as pumps and chemical treatment lines inside the plant building. The control room was also viewed. The tour then proceeded outdoors, visiting fill stands that deliver treated water to users without a potable connection as well as the well field in the Sheyenne National Grasslands. Production wells in the well field were observed to be secured and in good condition. The tour then concluded with visits to underground reservoirs identified as Reservoir N, Reservoir G, and the Hankinson Water Reservoir. The Site’s information repository is located at SEWUD’s headquarters; it is current and up to date.

12

V. TECHNICAL ASSESSMENT QUESTION A: Is the remedy functioning as intended by the decision documents? Question A Summary: Yes. The review of documents, data, Applicable or Relevant and Appropriate Requirement (ARARs), interviews and the results of the site inspection indicate that the remedy is functioning as intended by the ROD and ROD Amendment, as modified by the ESDs. EPA, NDDoH and SEWUD completed remedial construction activities at the Site in September 2011. The activities included the connection of cities to public water systems, the expansion of SEWUD-East water treatment facilities and the installation of pipelines to connect rural users to the public water supply. Private wells are not required to be abandoned as owners may use the well for purposes other than drinking. New private well owners identified during NDDoH’s database searches are provided a fact sheet to be informed of possible risks if the well is used for drinking. Treated water samples from SEWUD-East are sampled and analyzed annually for arsenic. Based on a review of available data, concentrations of arsenic in treated water remain below the current MCL. In addition, EPA and NDDoH have implemented informational institutional controls to educate, inform and notify residents and well drillers that shallow groundwater within the Site may contain arsenic levels above SDWA MCLs. EPA and NDDoH prepared a fact sheet in 2012 informing SEWUD-East members about the arsenic groundwater contamination from the Site and options available for residential users with concerns about their well water. In addition, the fact sheet is disseminated to well drillers, existing potable well owners and new well owners to help minimize the potential for human exposure to arsenic contamination in the future and protect the integrity of existing remedies. NDDoH is also working with EPA to revise the fact sheet to include information about the potential health effects of arsenic on livestock. Once finalized, the fact sheet will be made available to the public on the NDDoH, SEWUD and EPA websites. It will also be included in annual CCR mailings and provided to the State Board of Water Well Contractors, which includes the fact sheets in mailings to licensed well drillers each December. NDDoH recently established a schedule for providing EPA with summaries of NDDoH’s quarterly institutional control reviews to help keep EPA up to date on the status of existing institutional controls. The quarterly summaries include a summary of wells drilled within the site boundary, the purpose of the well and the date that the fact sheet was sent to the well owner. QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels and RAO used at the time of the remedy selection still valid? Question B Summary: Yes. The exposure assumptions, toxicity data and RAO used at the time of remedy selection are still valid. The cancer slope factor originally used to evaluate drinking water human health risks associated with arsenic at the time of the RI was 15 milligrams per kilogram per day-1 (mg/kg/day)-1, which is more stringent than the current cancer slope factor of 1.5 mg/kg/day-1. EPA revised the cleanup goal in the 2007 ESD to select the most current SDWA MCL rather than a risk-based concentration in drinking water. The availability of a less stringent toxicity value does not impact the protectiveness of the remedy. The annual monitoring of treated water from SEWUD-East indicates that dissolved concentrations of arsenic remain below the current MCL of 10 µg/L, which is also below the site background concentration of 25 µg/L.

The RI indicated that the most likely exposure pathway to arsenic is from human ingestion of groundwater or from consumption of locally-raised meat or dairy products. Any locally-produced meat or dairy products have the potential to contribute arsenic to the human diet, because the livestock may have been exposed for a significant length of time to elevated levels of arsenic in untreated groundwater. This exposure pathway may still be occurring, if domestic/irrigation wells continue to be used for watering livestock instead of using treated water from the distribution system. The RI also indicated that forage grasses and woody-stemmed bushes are not expected to contribute to elevated arsenic levels in locally-raised grazing animals, due to lack of uptake from soils. Contaminant source areas were not located during the RI. Samples taken along a confirmed area of bait-

13

spreading indicated no evidence of remnant arsenic within the soils, while samples collected from other areas of the Site yielded similar results.

According to the National Research Council (NRC), chronic oral arsenic toxicosis in domestic animals is seldom reported; this may be because arsenic is relatively nontoxic to domestic animals and is typically excreted in the urine rather than absorbed into their bodies.4 A study of dairy cows in Minnesota determined that arsenic does not transfer into milk or cheese, even from cattle exposed to arsenic at 10 times the human drinking water standard.5 In addition, the NRC indicates that arsenic is often added as a mineral along with other metals to livestock feed for growth promotion. Considering the low potential for uptake from site soils and for transfer through the food chain, the cleanup level and RAO are appropriate for this pathway. With respect to livestock and poultry, an acceptable upper limit of 200 µg/L for arsenic contained in water for livestock and poultry has been established by the Montana, Missouri and Ohio State Extension Services.6,7,8 The RI indicated that only seven of 437 public and private wells sampled exceeded the safe upper limit of 200 µg/L for watering livestock and poultry. NDDoH and EPA are currently revising the fact sheet to include information regarding uses of rural wells for watering livestock and poultry. Although a number of lakes are located within the site boundary, the RI determined the lakes are primarily recharging groundwater; thus, impacted groundwater is not discharging to the lakes. Further, although overland flow may occur during heavy precipitation events and during snow melt, which could transport soil to downgradient lakes, this contaminant migration pathway is considered incomplete, because source area soils were not identified during the RI. QUESTION C: Has any other information come to light that could call into question the protectiveness of the remedy? Question C Summary: No. No additional information has become available that could call into question the protectiveness of the remedy.

4 Mineral Tolerance of Animals: Second Revised Edition, National Research Council http://www.nap.edu/catalog/11309.html. 5 Assessing the Impact of Arsenic on Upper-Midwestern Dairy Operations. University of Minnesota, Water Resources Center. https://www.wrc.umn.edu/projects/ag-impacts/assessing-impact-arsenic-upper-midwestern-dairy-operations. 6 When is Water Good Enough for Livestock? By Jim Bauder MSU Extension Soil and Water Quality Specialist http://www.montana.edu/cpa/news/wwwpb-archives/ag/baudr146.html. 7 Water Quality for Livestock Drinking, By Donald L. Pfost and Charles D. Fulhage Agricultural Engineering Extension, University of Missouri Extension. http://extension.missouri.edu/p/EQ381. 8 Livestock and Water, by Stephen Boyles Ohio State University Extension Beef Specialist. Ohio State University Extension https://agnr.osu.edu/sites/agnr/files/imce/pdfs/Beef/LivestockAndWater.pdf

14

VI. ISSUES/RECOMMENDATIONS

Issues/Recommendations

OU(s) without Issues/Recommendations Identified in the FYR:

OU2

Issues and Recommendations Identified in the FYR:

OU(s): OU1 Issue Category: Institutional Controls

Issue: The publicly-available fact sheet has not been updated since the 2013 FYR to address the watering of livestock and poultry.

Recommendation: Update the fact sheet to include information regarding watering of livestock and poultry and ensure it is made available to the public.

Affect Current Protectiveness

Affect Future Protectiveness

Party Responsible

Oversight Party Milestone Date

No Yes EPA/State

EPA 12/15/2018

OTHER FINDINGS In addition, the following recommendation was identified during the FYR. This does not affect current or future protectiveness:

• Recommend updating the O&M Plan to specify that treated groundwater at SEWUD-East be analyzed for arsenic on an annual basis.

VII. PROTECTIVENESS STATEMENT

Protectiveness Statement(s)

Operable Unit: OU1

Protectiveness Determination: Short-term Protective

Protectiveness Statement: The OU1 remedy currently protects human health and the environment because the SEWUD-East water treatment plant has been upgraded and expanded to provide rural users, formerly on privately-owned, impacted wells, with potable water that meets the arsenic MCL. For the remedy to be protective over the long term, the fact sheet should be updated to discuss watering of livestock and poultry and be made available on the NDDoH, SEWUD-East and EPA websites.

Protectiveness Statement(s)

Operable Unit: OU2

Protectiveness Determination: Protective

Protectiveness Statement: The OU2 remedy is protective of human health and the environment. Rural users who had relied on the Wyndmere and Lidgerwood water treatment plants are now connected to the OU1 SEWUD-East water treatment plant.

15

Sitewide Protectiveness Statement

Protectiveness Determination: Short-term Protective

Protectiveness Statement: Because the remedial actions at OU1 are protective in the short term, the site remedy is protective of human health and the environment in the short term. For the remedy to be protective in the long term, the site fact sheet should be updated to discuss watering of livestock and poultry and be made available on the NDDoH, SEWUD-East and EPA websites.

VIII. NEXT REVIEW The next FYR Report for the Arsenic Trioxide Superfund site is required five years from the completion date of this review.

A-1

APPENDIX A – REFERENCE LIST North Dakota Department of Health, 2011. Arsenic Trioxide Superfund Site Fact Sheet: What You Should Know if You Drink Water from a Well. https://deq.nd.gov/Publications/WQ/1_GW/arsenic/ArsenicTrioxideSuperfundSiteFactSheet.pdf North Dakota Department of Health, 2016. Arsenic Trioxide Superfund Site Fact Sheet: What You Should Know if You Drink Water from a Well. https://deq.nd.gov/Publications/WQ/1_GW/arsenic/ArsenicTrioxideSuperfundSiteFactSheet.pdf. Southeast Water Users District, 2013. Consumer Confidence Report (CCR). https://seh2o.com/pdf/CCR-2013.pdf. Southeast Water Users District, 2014. Consumer Confidence Report (CCR). https://seh2o.com/ccr/CCR-Main-Report-2014.pdf. Southeast Water Users District, 2015. Consumer Confidence Report (CCR). https://seh2o.com/ccr/CCR-Main-Report-2015.pdf. Southeast Water Users District, 2016. Consumer Confidence Report (CCR). https://seh2o.com/ccr/2016-SEWUD-CCR.pdf. Southeast Water Users District, 2017. Consumer Confidence Report (CCR). https://seh2o.com/image2/files/e647590739d52b806ea945dbca0967e37f02aa41.pdf. Southeast Water Users District, 2014. Water Analysis East 2014. Southeast Water Users District, 2015. Water Analysis East 2015. Southeast Water Users District, 2016. Water Analysis East 2016. Southeast Water Users District, 2017. Water Analysis East 2017. https://seh2o.com/image2/files/6eff19203a3ebd20408fdfb80195481cefb7f3e3.pdf. Southeast Water Users District, 2018. Water Analysis East 2018. https://seh2o.com/image2/files/2473a8799dd7eadff22f65e77757895634e5c736.pdf. United States Environmental Protection Agency, 1986. OU1 Record of Decision, EPA ID NDD980716963. United States Environmental Protection Agency, 1988. OU2 Record of Decision Amendment, EPA ID NDD980716963. United States Environmental Protection Agency, 1992. OU2 Explanation of Significant Differences, EPA ID NDD980716963. United States Environmental Protection Agency, 1992. Preliminary Close Out Report, EPA ID NDD980716963. United States Environmental Protection Agency, 1993. Final Close Out Report, EPA ID NDD980716963. United States Environmental Protection Agency, 1999. First Five-Year Review, EPA ID NDD980716963. United States Environmental Protection Agency, 2003. Second Five-Year Review, EPA ID NDD980716963.

A-2

United States Environmental Protection Agency, 2007. OU1 Explanation of Significant Differences, EPA ID NDD980716963. United States Environmental Protection Agency, 2008. OU1 Explanation of Significant Differences, EPA ID NDD980716963. United States Environmental Protection Agency, 2008. Third Five-Year Review Report, EPA ID NDD980716963. United States Environmental Protection Agency, 2009. OU1 Explanation of Significant Differences, EPA ID NDD980716963. United States Environmental Protection Agency, 2009. Remedial Action Report Rural Water System Expansion – Segment 3, EPA ID NDD980716963. United States Environmental Protection Agency, 2010. Annual Update to the Five-Year Review, EPA ID NDD980716963. United States Environmental Protection Agency, 2013. Fourth Five-Year Review, EPA ID NDD980716963.

B-1

APPENDIX B – SITE CHRONOLOGY

Table B-1: Site Chronology

Event Date EPA site discovery June 1, 1981 NDDoH completed first site inspection August 1, 1982 NDDoH started RI for OU1 August 24, 1982 EPA proposed Site for listing on NPL December 30, 1982 EPA listed Site on NPL September 8, 1983 NDDoH completed second site inspection May 1, 1984 NDDoH issued final RI Report and started FS for OU1 July 1, 1985 EPA started the first removal action, which included installing a clay cap over a former bait-mixing station and installing point-of-use treatment units in rural residences on private wells

September 15, 1986

NDDoH completed the OU1 Final FS Report and EPA issued the OU1 ROD September 26, 1986 EPA completed first removal action December 10, 1986 NDDoH started remedial design for OU1 March 26, 1987 NDDoH started combined RI/FS for OU2 April 29, 1987 NDDoH completed OU2 RI/FS and EPA issued ROD Amendment for OU2 February 5, 1988 NDDoH began first OU2 remedial design February 17, 1988 NDDoH began second OU2 remedial design June 29, 1988 NDDoH completed second OU2 remedial design September 26, 1988 EPA started the second removal action October 24, 1988 NDDoH started first OU2 remedial action March 9, 1989 NDDoH completed first OU2 remedial design and started remedial action March 31, 1989 EPA completed second removal action June 9, 1989 NDDoH completed remedial design for OU1 June 28, 1989 NDDoH completed first and second OU2 remedial actions March 21, 1991 EPA signed ESD for OU2 September 25, 1992 NDDoH completed remedial action of rural water system to add the city of Milnor and EPA issued Preliminary Close-Out Report September 30, 1992

EPA conducted final inspection of remedial action construction at Milnor and issued Final Close-Out Report June 30, 1993

SEWUD assumed O&M responsibility for Richland plant July 1, 1993 EPA deleted Site from NPL July 5, 1996 EPA completed Site’s first FYR January 19, 1999 EPA lowered SDWA MCL for arsenic from 50 µg/L to 10 µg/L, to become effective January 2006 January 22, 2001

EPA completed Site’s second FYR June 11, 2003 EPA started RI/FS for OU1 to address expansion of SEWUD to address new MCL for arsenic June 25, 2003

NDDoH started remedial design for SEWUD expansion September 20, 2004 NDDoH started construction of Segments 1 and 2 of SEWUD expansion August 8, 2005 EPA provided bottled water to rural users with sampling results showing arsenic levels 10 µg/L or greater June 4, 2007

EPA issued second ESD for OU1 September 27, 2007 EPA issued third ESD for OU1 February 25, 2008 NDDoH started construction of Segment 3 to connect cities of Hankinson and Wyndmere to SEWUD June 10, 2008

NDDoH completed construction of Segments 1 and 2 September 25, 2008 EPA completed Site’s third FYR September 26, 2008 EPA’s removal program transferred bottled water program to NDDoH October 1, 2008 EPA completed RI/FS for OU1 and signed fourth OU1 ESD February 20, 2009 NDDoH started Segment 4 and 4a construction May 1, 2009

B-2

Event Date NDDoH completed remedy construction of Segment 3, connecting 60 rural users to SEWUD September 29, 2009

EPA issued a FYR update February 1, 2010 NDDoH completed remedial design for next phase of SEWUD expansion March 30, 2010 NDDoH started Segment 5 construction April 20, 2010 NDDoH completed Segment 4 and 4a construction, connecting about 119 rural users to SEWUD November 30, 2010

NDDoH completed Segment 5 construction September 1, 2011 EPA issued Site’s Final Remedial Action Report for SEWUD expansion September 29, 2011 EPA completed the Site’s fourth FYR September 30, 2013

Table B-2: Summary of OU1 Remedy Construction Activities Post Site Deletion

Segment Construction Activities Date Completed

1

City of Wyndmere • Installation of 11 miles of new waterlines from an existing line to a new 100,000-

gallon underground water storage reservoir. • Construction of a pumping facility on a vacant lot directly west of the existing

Wyndmere water treatment plant. • Modifications to SEWUD-East’s existing Reservoir B pumps, piping and controls.

August 2005 to October 2006

City of Hankinson • Installation of three miles of new waterlines from an existing line to a new 200,000-

gallon underground water storage reservoir. • Construction of a pumping facility in Hankinson. • Improvements to Hankinson’s water distribution system also provided water to

eight households within city limits that did not previously have municipal water service.

2

• Well field expansion and expansion of the SEWUD-East • Completion of two production wells. • Installation of 3,200 feet of piping to connect the new production wells to their tie-

in with the existing transmission line. • Expansion of the existing water treatment plant building to include an addition

directly north of the existing building and the installation of new equipment (e.g., new water filters, high service pumps, backwash pumps, chemical feed equipment, miscellaneous process piping, valves and fittings, clear well, chemical feed room, an operator control room, and an electrical/motor control center room).

• Modifications to the backwash and sanitary sewer pond at the treatment plant site.

May 2006 to August 2007

3 Rural households north and west of Wyndmere and south and west of Hankinson • Installation of 36 miles of water line and associated valves, hydrants, curb stop

assemblies and residential meter units.

June 2008 to August 2009

4 Rural users and cities of Cayuga and Geneseo • Connect about 125 rural users to SEWUD-East and to the cities of Cayuga and

Geneseo.

May 2009 to November 2010

4a Rural users and cities of Cayuga and Geneseo • Expansion of water supply reservoirs B and G to supply new customers.

October 2009 to July 2010

B-3

Segment Construction Activities Date Completed

5

• Expansion of the well field to ensure availability of an adequate quantity of raw water, including connecting the city of Lidgerwood and other users.

• Upgrade of the water treatment facility with an additional filter vessel. • Construction of a new reservoir and pump station to maintain adequate flows to an

area previously unserved by rural water. • Upgrade of four pump stations so that adequate service would be provided to new

users and so that existing users maintained the level of service experienced prior to the expansion.

• Construction of two new storage reservoirs to provide system capacity. • Installation of an emergency generator to diminish the impact of service

interruptions because of loss of power. • Installation of a geothermal system to lessen the system’s dependence on non-

renewable energy sources. • Installation of water lines and associated valves, hydrants, curb stop assemblies and

residential meter setter units to provide water service to about 132 rural households. • City of Lidgerwood signed a water purchaser agreement with SEWUD on February

11, 2010.

April 2010 to September 2011

Table B-3: Summary of OU2 Remedy Construction Activities

Construction Activities Date Completed City of Lidgerwood a

• Expansion of the treatment building. • Construction of a 23,000-gallon potable water storage reservoir,

automation of the backwash system and several operational changes.

August 1989 to January 1990

City of Wyndmereb • Construction modifications to increase treatment capacity and the

addition of a 50,000-gallon potable water storage tank. • Modifications to the backwash filters and post-chlorination unit.

August 1989 to January 1991

Notes: a. City of Lidgerwood was connected to the SEWUD system and became part of OU1 in 2010 using

ARRA funding made available to NDDoH. b. City of Wyndmere was connected to the SEWUD system as part of OU1 Segment 1 construction in

October 2006.

C-1

APPENDIX C – NDDOH CORRESPONDENCE, SITE FACT SHEET AND QUARTERLY REPORTING

Sample NDDoH Letter to Owners of New Wells June 22, 2017 Dave Mogren 9175 Highway 18 Lidgerwood, ND 58053 Subject: Arsenic Trioxide Superfund Site This letter is to inform you that our records indicate that you recently installed a drinking water well within the Arsenic Trioxide Superfund Site and your well may be at risk for elevated levels of arsenic. Arsenic is a toxic chemical that occurs naturally in the environment in the soil, rock and minerals, but it can also appear as a by-product of agricultural and industrial uses. In certain areas within Richland and Sargent counties, arsenic-laced bait was used extensively to combat grasshopper infestations during a period from the 1930’s – 1940’s. This bait was commonly applied to farm fields and unused materials were often buried in pits or other low-lying areas nearby. The use and disposal of this arsenic may have contributed to the elevated concentrations of arsenic found in groundwater in some areas of the site. Since your property lies within the boundaries of the Arsenic Trioxide Superfund Site, we are sending this Fact Sheet that explains the site in more detail. Please do not hesitate to contact me at 701-328-4164 or ctgleich@nd.gov if you have any questions. Sincerely; Casey T. Gleich Environmental Scientist II NDDoH – Division of Water Quality Encl. Arsenic Trioxide Superfund Site Fact Sheet

C-2

~i N ORTH D A KOTA '1111111111~ DEPARTMENT of HEALT H

Contacts

Carl Anderson, Superv isor

Groundwater Protect ion Program

North Dakota Dept . of Healt h

Water Qualit y Division

918 East Divide Avenue

Bismarck, N.D. 58501- 1947

701-328- 5213

www.ndhealth .gov

Southeast Water Users Dist r-ict

206 Main Street

PO Box 10

Mantador, N.D. 58058-0010

701-242- 7432

www.seh2o.com

Fran Costanzi, Project Manager

U.S. EPA, Region 8

1595 Wynkoop Street (EPR-SR)

Denver, CO 80202- 1129

303-3 12- 6571

800-227-8917 ( toll free Region 8)

www2.epa .gov/region8/arsenic­

t rioxide

Arsenic Trioxide Superfund Site Fact Sheet

What you should know if you drink water from a well

Drinking-Water Well Users May Be at Risk Homem,vners and potential buyers of homes with existing water wells in Richland and Sargent counties in North Dakota, as ,.vell as anyone considering drilling a new well in the area, should be aware that shallow aquifer groundwater may contain elevated levels of arsenic.

The U.S. Environmental Protection Agency (EPA), in cooperation with the North Dakota Depa1tment of Health (NDDoH) and the Southeast Water Users District (SEv\TUD), has taken steps to remedy the health risk posed by arsenic in the area identified as the Arsenic Trioxide Superfi.md Site. The area encompasses about 936 square miles in southeast North Dakota and includes 26 townships.

What is Arsenic, and Why is It a Problem? Arsenic is a toxic chemical that occurs

naturally in the environment in the soil, As O rocks and minerals. It can also appear

2 3 as a by-product of agricultural and

industrial use. In Richland and Sargent counties, arsenic-laced bait was used e;\,1:ensively to combat grasshopper infestations during the 1930s and early 1940s. The bait was commonly applied to farm fields, and unused materials were often buried or dumped in pits or low-lying areas.

In 1979, in the communities of Lidgerwood, vVyndmere and Milnor, shallow wells in the shallow upper were discovered to contain arsenic at concentrations above the drinking water standard of so paits per billion (ppb). Arsenic was also found in wells at private homes and farms in unincorporated areas. In 2006, the standard for ai·senic was changed from so ppb to 10 ppb, which is roughly equivalent to a few drops of ink in an Olympic-size s,vimming pool.

Continued on reverse

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Some people who drink water containing arsenic in excess of the standard over many years could experience adverse health effects, such as skin damage or circulato1y system problems, and may have an increased risk of getting cancer. Short-term exposure to high doses of arsenic in drinking water (about a thousand times higher than the 10 ppb drinking water standard) can also cause adverse effects in people. Such e)l.'-pOsures are not known to occur from public water supplies in the U.S. that comply ,vith the drinking water standard for arsenic.

What Should I Do to Limit My Risk? Owners of existing groundwater wells should determine if their water has been tested for arsenic levels. NDDH, in Bismarck, N.D., maintains records of previously tested wells and ,vill provide results to owners at no charge. If your well has not been tested, contact NDDoH for more information or view the brochure at ,vww.ndhealth.gov / WQ/ GW / pubs/ WellTestingBrochure. pdf.

Should arsenic levels exceed the 10 ppb drinking water standard, uwners of wells ;vith water intended for household use (drinking, cooking, etc.) have several options:

• Household point-of-use treatment- water purification units installed at owners' homes,

• Connection to the public water supply- contact SEWUD for details, or

• Using bottled drinking water.

These are options for well owners to consider. The well owner is responsible for the costs related to these options.

What Happens Next? EPA and NDDoH have completed the remediation activities at the site, which has included the connection of cities to public water systems, the eA'-pansion of SE\!VUD water treatment facilities and the installation of pipelines to connect rural users to the public water supply.

Ongoing measures include the creation of Institutional Controls (ICs) by EPA and NDDoH. ICs are "non-engineered instruments,"

such as administrative and legal controls, that will help minimize the potential for human exposure to arsenic contamination in the future and protect the integiity of existing remedies. This fact sheet is a pait of the IC for the Arsenic T1ioxide Supe1fund Site.

Tow nships in the Arsenic Trioxide Superfund Site

Richland County

Barney

Belfo rd

Brightwood

Danton

Dexter

Duerr (East)

Duerr ( West)

Elma

Grant

Homestead

Liber ty Grnve

Moran

West End

Wyndmere

Sargent County

Dunbar

Hall

Herman

Kingston

Marboe

Milno r

Ransom

Rutland

Shuman

Tewaukon

Weber

Wi lley

I]{]?>. SOUTHEAST ~WATER USERS

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~« NORTH DAKOTA ENVIRONMENTAL HEALTH SECTION

Gold Seal Center, 918 E. Divide Ave.

~ , DEPARTMENT of HEALTH

July 2, 2018

Frances L. Costanzi, P. E. Remedial Project Manager and Superfund Redevelopment Initiative Coordinator USEP A Region 8 1595 Wynkoop Street Mail code 8EPR-SR Denver, CO 80202

Bismarck. ND 58501-1947 701.328.5200 (fax) www.ndhealth.gov

Re: Arsenic Trioxide Superfund Site Quarterly Activity Summary

Ms. Costanzi,

The North Dakota Department of Health (NDDoH) is pleased to present this summary of tasks completed as part of the on-going remedy for the North Dakota Arsenic Trioxide Superfund Site (ATS). This report covers the period from March 3 l to June 30, 2018.

Communications with Stakeholders, EPA, and SEWUD

The NDDoH attended the ATS Five-Year Re:view Meeting held in Matador on May 24, 20 18. The review meeting included a brief project update discussion and a tour of SEWUD's water treatment plant and several reservoi rs/pump stations installed at part of the. ATS Project. The water treatment plant and water distribution system are working as designed and the treated water meets all reequipments of the Safe Drinking Water Act. The arsenic concentration in the treated water is below the arsenic Maximum Contaminant Level of IO parts per billion.

Institutional Controls

The NDDoH completed well installation reviews on April 16 and May 29, 2018. The reviews consisted of a search of the State Water Commission's boring contractor logs to identify wells installed with in the boundary of the ATS. No additional wells installed during the reporting period were identified. A cumulative summary of well searches is summarized on the attached table.

Please do not hesitate to call me at 701-328-5213 or email me at c jandes@nd.gov if you have any questions or require additional infom1ation.

Sincerely,

~~ Carl Anderson NDDoH-Division of Water Quality

Environmental Health Section Chiefs Office

701.328.5150

Division of Air Quality

701.328.5188

Division of Municipal Facilities

701.3.28.5211

Printed on recycled paper.

Division of Wasta Management

701 .328.5168

Division of Water Quality 701.328.5210

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Wells Drilled within the ATS Boundary between 20il-2018 Township Well Purriose Date Drilled Mail Sent?

132a050~21 CCC Domestic I itOt/ll YES [3:2-053~04 coc Domestic, l 2106/12 YES 130-052-i 3 BCS Domestic. 09ilO/i 1 YES 13.0-052--14 D AA Domestic l liOI/U YES 130-052~13 BCB Unknown 03/25/11 YES

133_-051-18 B. lJn.known 12(.09/11 YE$ 13)-052-.33 B Uriknown 02/02/12 YES J33°Q52-)2 P Unknown 02/02/12 YES 132-054-12 D Unknown 0911$/11 YES 132,os4-09 n Unknown 09/02/12 YES

130-052-13 BAA. Domestic 05/25/12 YES 129-05 l-11 DDB Doniesiic/Stock 04/05/13 YES 129-053-24 DOD Domestic t l/08/12 YES i32-'l)51-28 BAB Domestic 07/30/12 YES 131-050~05 BBC Domestic : 06/08/12 YES i30-050-02 BCB Murucipal l l/09/12 YES

B0-051-23 A Unk.1101.vn 05/04/13 YES 130-050-14 BO Unknown 05/19/13 YE$ 130°052-14 A V:riknown 06/07113 YES

133~052-14 DAD Stock 12/15(11 YES 132-05.4-01 C $tock (i9/J0/i3 YES

B0-0.51-12 CBB St~k, 05/10/B YES, 130~(J5 l • l 3 CBC Stock 05/17/i.3. YES

133-051-31 C lliiluio.wn 11/20/13 YES 130-052-26 D Domestic/Stock 12/04/13 , YES 133~052-12 Stock 12/27/13 YES 133-051-18 Domestic 12/27/13 YES

Bl ~053- 14 A Unknown 03/10/14 YES 13 1-053-14 C Uriknov\1[1 03/19i14 YES

131-052-26 ABB Domestic/Stock l l/01113 YES 132-052-20 CCC Domestic 04/30/13 YES I 31-051-36 DCB Stock 08/26/14 YES I i0-052-0 I . ODD Domes.tic 09/25/14 YES 133-054-35 CCD Stock 09/19/l3 YES l j0-0.50-25 BBB Domestic. 10/22/15 YES

.133-054~31 Stock ·06109./14 YES 131.-049-15 ODO Domestic 06103/11 YES 13i ~049-29 DCC Domestic 0.8/10/JS YES 130-050;24 DDC Domestic O:i/.20/16 YES 131)-05.0-2(i BCD Dorp.estic 11/15./14 YES l 32-053.-.26 DD.A .· Domestic 04/17/14 YES 129. oss-30 ccp Stock ·0<;11s1i 6 YES D0-051-35 A.AA Pomestjc, 05/05/16 YES 13.0-052-12 CAA Stock 02/15/17 YE.s

C-6

Well Search Summar.r ))ate Dat~.base was Searthed Database Searched

7/25/2012 No wells foun\i in datab.ase for time period North Dakota State Water Conimissio11 (SWC) 9/19/2012 No wells found in database for time p.erio~ North Dukota 'sta:te WaterComniission (SWC) 12127/2012 4 new domestic i.vells found for time period SWC. J/7/20JJ 6 new wells found in database for ti ine period SWC & Nor(b Dakota One Cali (NDI) 6/2()/2013 9 new wells found.in database Joi- time period SWC&ND I 9/.20/2013 0 new wells found j11 datal:\ase for iime perk)d SWC&ND I 12il7/2013 5 itew wells found in databases fortime period SWC &NO i J/.20/Wi4 5· new wells found.in databases for time period SWC &NDf 6/20/2014 2 m;ww~ils found in database for time period SWC &NDI 9/20/2014 1 new wellJound in c\aiabase for•lime ~rio.d SWC&NDI 1/12/201.5 l new wel I found in database for lime per foe( SV,/C .& NDI 3/2/Wl5 0 ne.,v wells found ii, databasC! for time period SWC &N.DI

6/17/20l5 0 new wells found in dar,ihase for time period SWC &NDl 9/15/20 [5 0 new .,veils found in database for lill)e period SWC&NDI 12/l/2015 4 new wells fou nd in c/afabase for ti.me oeriod SWC .&'.NDI 3/f/201.6 0 new wells:founa.in database foj- time oeriod s.wc 011311016 3 new wel)s fo.tirrd in clatitbase for time rieriod swc 9/6/2016 1 .new weil found in databa~e for.time oer1od swc

12/15/2016 0 1iew wells found in ,database fo.r time oeriod swc 3/21/2(117 0 new wells. found in 'database for Lime period swc 6/22/20i7 2 .new ,vells fouird •in database for time pedod swc 9/21/2017 0 new,wo;:ils found in database for time period swc !2il3/20!7 0 ,ne"' ivells found iu database for time p!lri,od swc 4/16/20.18 0 ucw wells found in da!aiiase for time:period swc 5/29/2018 0 ne\v wells found in. dat'Jbase for time period swc

D-1

APPENDIX D – JULY 20, 2018 PRESS NOTICE

PUBLIC NOTICE

U.S. Environmental Protection Agency, Region 8 and the No rth Dakota Department of Health Announce the Fifth Five-Year Review

for the Arsenic Trioxide Superfund Site, Richland, Ransom and Sargent counties, NO

Purpose/Object ive: The U.S. Environmental Protection Agency {EPA) and the NO C>epartment of H e.llth (NDDoH) are conducci"9 the fifth Five-Year Review of the remedy for the Arsenic T rioxide Superfuncl site (the Site) i':n Rich.land. Ransom and Sargent coun­ties. ND. The purpose of the Five-Year Review is to make sure that selected cleanup actions effeciively protect human health and the environment.

Sit e Background: The Site is located in southeastem North Oakot3. It covers 26 town­ships aOO 940 square miles. ind ucting portion.s of Richland, Ransom and Sargent coun­ties. The use of arsenic-laced bart to combat gra sshopper infesta:ions during the 1930s and 1940s resulted in contamination of groundwater in the communities of Lidgerwood, Wyndme re and M ilnor. as welJ as at private homes and farms in uninoorpora:ed areas.

Cleanup Actions: EPA. in ooopel'ation with rthe NDDoH and the Southe.lSt Water U sers District have taken steps to rem edy the h ealth risk posed by the arsenic on site. EPA issued sev eral decision documents to addtMs the different ph.lSes of cleanup. EPA and the NDDoH then comple4:ed cleanup activities at the Site. These efforts included connecting localities to public water systems. expandi"9 district water treatment facilities. installing pipelines to connea rural users to pub lic water supplies and putti"9 m.iltiple layers of institutional controls in place.

Five-Y,ear Rev iew Schedule: The National Contingency Plan requires review of remedial ac(ions that result in any hazardous s ubstances. pollutants or contaminants remaining at the Site above levels that allow for unlimited use and unrestricted exposure every five y ears to ensure the pt'O(ection of human health and the environment. The Fifth Five-Year Review for the Site wiD be completed by September 20 18.

EPA and the NOOoH invite community partic ipat ion in t he F ive-Year Review pro­cess: The agencies are conduccing this FJVe-Ye ar Re\lfew to evaluate the effectiveness of the Site's remedy and to en sure that the remedy remains pro~eaive of human health and the environm ent. A s part of the Five-Year Review process. EPA and NDDoH staff meni>er-s are available to answer any questions about the Site. Community members who hav e questions about the Site or the Frve-V ear Review process. or who would like to participate in a community in terview. are asked to contact:

EPA Frances Costanzi. Remedial Project Manager Phone: 303-312-6571 or 1-800-227-89 17 {Region 8 only) EmaiJ: oostanzi.frances@epa.gov Mailing Address: U.S . EPA R egion 8 (EPR-SR) 1595 Wynkoop Stree4: Denve.r. CO 80202-1129 N OOolH Cart Anderson. Supervisor Phone: 701-328-5213 Email: cjanders@nd.gov Mailing Address: North Dakota Department of H ealth Diviskin of Water OuaJity 9 18 East Divide Avenue, 4Ch Floor Bismarck. ND 5850 1- 1947 Site information is also available at the Southeast Water Users District (206 Main

Street. M antador, North Dakota 58058). Lidgerwood Public U.brary { 15 Wiley Avenue, Lidgerwood, ND 58053) and EPA "s Supe.rfund R ecords Center ( 1595 Wynkoop Street. C>enver. CO 80202-1129). and on1ine at h ttp://www.epa.gov/superfund'arsenic-trioxide.

Legal No. 67811 - Published F riday . J uly 20, 2018

E-1

APPENDIX E – INTERVIEWS Arsenic Trioxide Superfund Site Five-Year Review Interview Form Site Name: Arsenic Trioxide EPA ID No.: NDD980716963 Interviewer Name: Claire Marcussen Affiliation: Skeo Solutions Subject Name: Carl Anderson Affiliation: NDDoH Time: 9:00 A.M. Date: 06/04/2018 Interview Format (circle one): In Person Phone Mail Other: Email Interview Category: State Agency

1. What is your overall impression of the project, including cleanup, maintenance and reuse activities (as

appropriate)?

The project provided qualified rural residents located within the site boundary with the opportunity to obtain a safe source of drinking water by providing rural water supplied by SEWUD. The project required a cooperative effort between state and federal agencies, SEWUD, and rural residents. The remedy implemented was successful at meeting the objectives of the project.

2. What is your assessment of the current performance of the remedy in place at the Site?

SEWUD is required to comply with the SDWA, which includes compliance sampling. SEWUD collects annual samples for arsenic testing to ensure that the water supplied to rural residents meets the federal MCL of 10 µg/L for arsenic. The arsenic concentration in all compliance samples has been below the arsenic MCL. Consequently, the water treatment system is providing water that is protective of human health.

3. Are you aware of any complaints or inquiries regarding site-related environmental issues or remedial

activities from residents in the past five years?

No. 4. Has your office conducted any site-related activities or communications in the past five years? If so, please

describe the purpose and results of these activities.

Yes, as part of the institutional controls for the project. The Department conducts searches for new wells installed within the site boundary; the review is conducted by reviewing well drilling logs sent to SWC. Owners of new water supply wells are sent a letter discussing the project and a copy of the site fact sheet. The site fact sheet is also sent to North Dakota well drillers along with their annual well certifications.

5. Are you aware of any changes to state laws that might affect the protectiveness of the Site’s remedy?

No. 6. Are you comfortable with the status of the institutional controls at the Site? If not, what are the associated

outstanding issues?

Yes. 7. Are you aware of any changes in projected land use(s) at the Site?

No. 8. Do you have any comments, suggestions or recommendations regarding the management or operation of the

Site’s remedy?

E-2

SEWUD is responsible for the oversight, operation, and maintenance of the water treatment plant and the water distribution system and is required to maintain compliance with the provisions of the SDWA. SEWUD has provided reliable service and I expect that to continue. NDDoH will look for additional ways (e.g., maps/data available on the Department’s website) to make arsenic information available to the public.

9. Do you give permission for the following to be included in the FYR Report and appendices, which becomes a public document? Please initial below. a) Your name? Yes ____X__ No ______ b) Your affiliation? Yes ___X___ No ______ c) Your responses? Yes ___X___ No ______

E-3

Arsenic Trioxide Superfund Site Five-Year Review Interview Form Site Name: Arsenic Trioxide EPA ID No.: NDD980716963 Subject Name: Steve Hansen Affiliation: SEWUD Time: 9:30 A.M. Date: 05/22/2018 Interview Format (circle one): In Person Phone Mail Other: Email Interview Category: O&M Contractor

1. What is your overall impression of the project, including cleanup, maintenance and reuse activities (as

appropriate)? I thought the overall project went very well. We were able to get quality drinking water to many rural users along with two cities. The contractors did a good job with the cleanup. The improvements to our existing infrastructure are working well.

2. What is your assessment of the current performance of the remedy in place at the Site?

The remedy is working as intended with no problems.

3. What are the findings from the monitoring data? What are the key trends in contaminant levels that are being documented over time at the Site?

The arsenic levels of our treated water have remained consistent. It is below the MCL. The raw water arsenic has also stayed the same over the years.

4. Is there a continuous on-site O&M presence? If so, please describe staff responsibilities and activities. Alternatively, please describe staff responsibilities and the frequency of site inspections and activities if there is not a continuous on-site O&M presence.

The staff is at the water treatment plant daily taking water tests to make sure it is working properly. We can also monitor the plant remotely from our SCADA system we have on our computers.

5. Have there been any significant changes in site O&M requirements, maintenance schedules or sampling

routines since start-up or in the last five years? If so, do they affect the protectiveness or effectiveness of the remedy? Please describe changes and impacts.

There have been no significant changes in our plant operations and our finished water has remained consistent over the years and we have continued to upgrade equipment as needed.

6. Have there been unexpected O&M difficulties or costs at the Site since start-up or in the last five years? If so,

please provide details.

There have been no unexpected O&M difficulties just the normal maintenance issues that go along with running a water system.

7. Have there been opportunities to optimize O&M activities or sampling efforts? Please describe changes and any resulting or desired cost savings or improved efficiencies. With the upgrades to our SCADA system and the addition of variable frequency drives to our pumps, we are able to run at peak efficiency, saving us on our electrical costs.

8. Do you have any comments, suggestions or recommendations regarding O&M activities and schedules at the Site?

E-4

I think things are operating as intended as long as we keep doing the normal O&M on the system to keep it running as efficient as possible.

9. Do you give permission for the following to be included in the FYR Report and appendices, which becomes a public document? Please initial below. a) Your name? Yes __X__ No ______ b) Your affiliation? Yes __X__ No_______ c) Your responses? Yes __X__ No ______

E-5

Arsenic Trioxide Superfund Site Five-Year Review Interview Form Site Name: Arsenic Trioxide EPA ID No.: NDD980716963 Subject Name: Brian R. Bergantine, P.E. Affiliation: AE2S Time: Date: 06/05/2018 Interview Format (circle one): In Person Phone Mail Other: Email Interview Category: O&M Contractor 1. What is your overall impression of the project, including cleanup, maintenance and reuse activities (as

appropriate)?

Overall, I believe the project went very well. This project allowed many users who had elevated concentrations of arsenic in their current water to be served good quality water from SEWUD, including the cities of Hankinson and Wyndmere. Another item that makes me believe it was successful was that one of the first-round remedies was a new water treatment plant for the City of Lidgerwood to address its arsenic issues. Ultimately, the Lidgerwood Water Treatment Plant was demolished and the City hooked up to SEWUD like these other two cities. The cleanup by the contractor went very well and SEWUD continues to do ongoing maintenance on its system to ensure that they provide potable, good quality drinking water to the users under this project.

2. What is your assessment of the current performance of the remedy in place at the Site?

My assessment of the current performance of the remedy in place is that it is doing an excellent job of removal of arsenic without any real issues. In fact, SEWUD recently took third place at the National Rural Water Conference for its drinking water quality.

3. What are the findings from the monitoring data? What are the key trends in contaminant levels that are being documented over time at the Site? The arsenic concentration for the water produced by SEWUD has continued to stay below the MCL for arsenic, meeting EPA’s standard.

4. Is there a continuous on-site O&M presence? If so, please describe staff responsibilities and activities. Alternatively, please describe staff responsibilities and the frequency of site inspections and activities if there is not a continuous on-site O&M presence. SEWUD has staff that monitor the water quality on a daily basis from the SEWUD-East Water Treatment Plant.

5. Have there been any significant changes in site O&M requirements, maintenance schedules or sampling

routines since start-up or in the last five years? If so, do they affect the protectiveness or effectiveness of the remedy? Please describe changes and impacts. No significant changes have been made to the site O&M requirements, maintenance schedules, or sampling routines since start-up.

6. Have there been unexpected O&M difficulties or costs at the Site since start-up or in the last five years? If so,

please provide details.

No.

7. Have there been opportunities to optimize O&M activities or sampling efforts? Please describe changes and any resulting or desired cost savings or improved efficiencies.

E-6

SEWUD continues to make upgrades and improvements to their system by enhancements through the SCADA system to be more efficient in its electrical and chemical usage. The SCADA system allows SEWUD to be more accurate on dosage and variable frequency drives have allowed their system output to match the demands in the system, saving on electrical costs.

8. Do you have any comments, suggestions or recommendations regarding O&M activities and schedules at the

Site? No. I think as long as SEWUD continues on its current O&M schedule, they will produce excellent water quality for their customers being served under the Arsenic Trioxide Superfund project.

9. Do you give permission for the following to be included in the FYR Report and appendices, which becomes a public document? Please initial below. a) Your name? Yes ___X___ No ______ b) Your affiliation? Yes ___X___ No ______ c) Your responses? Yes ___X___ No ______

F-1

APPENDIX F – DATA REVIEW Table F-1: April 2014 Laboratory Results for Treated Water for SEWUD-East

Public Health Pr.ev&nt. Promote. Protect .

Pllf'I() CllM PubUo Hell.Ith

Southeast Water Users 206 Main St Mantador, ND 58058

Phone: 701-242-7432

Fax:

Customer Sample Number:

Collection Site: SEWU - East

Collection Date: 4/8/2014

Collection Time: 8:56 AM

Analyte

Nitrate-Nitrite as N

Arsenic

Conductivity

pH

Total Dissolved Solids (TDS)

Turbidity

Chloride

Fluoride

Sulfate

Calcium

Iron

Magnesium

Fargo Cass Public Health Environmental Laboratory

435 14th Avenue South Fargo, ND 58103

Phone 701-298-6986 Fax 701-241-8100

Order Number: 14-161 Sample Number: 14-372

Receive Date: 4/8/2014

Receive Time: 8:56 AM

Project:

Collected by: CL

Matrix: Water

Results for 14-372 Analysis Analysis

Result Method Date Time Analyst

< 0.200 mg/L EPA 300.0 4/9/2014 9:00AM M. Amundson

8.50 ug/L EPA200.9 4/11/2014 10:00AM C. Ohman

409 uS/cm SM 2510 B 4/8/2014 12:30PM N.Bartnlck

7.4 SM 4500-H B 4/8/2014 12:45 PM N. Bartnick

294 mg/L SM 2540C 4/912014 8:50AM Kim Jirava

< 0.01 NTU EPA 180.1 4/81201 4 11:50AM N. Bartnick

4.45 mg/L EPA300.0 4/9/2014 9:00AM M. Amundson

0.871 mg/L EPA300.0 4/9/2014 9:00AM M.Amundson

24.5 mg/L EPA 300.0 4/9/2014 9:00 AM M. Amundson

74.3 mg/L EPA 200.7 4/10/201 4 10:00AM C. Ohman

< 0.020 mg/L EPA200.7 4/10/2014 10:00AM C. Ohman

14.9 mg/L EPA200.7 4/10/2014 10:00 AM C. Ohman

Approved By: @Jif!U Date: O~-lf lY Page 1 of 4

The missio11 of Fargo Cass Public Health is to assure a healthy rommunify for all the 1>eople through on~going assesstnenl, cducittion, advocacy, intervention. prevention, and collaboN1tlon E~o·

F-2

Table F-2: February 2015 Laboratory Results for Treated Water for SEWUD-East

Report of Analysis

Fargo Water Treatment Plant Environmental laboratory

~35 Mth Avenue South

Fargo, ND 56103

Phone: (701) -296-6966

Fax: (701)-241-6110

SEWUD-East PO Box 10 Mantador, ND 58058

A ttention:

Lab Sa,nple 10: 15_021002-01

Silo:

Comment

Projecl ID:

Email: SEWU@RRT.N ET

Collection Date: 2/10/2015

Location:

~ _i . · · • , i•.'· · ': ~~"s""""'"'P:.::l•,.R,.,e'"·•"'· u,,11,..·:c· ==-=-= -"-""'--" . .'Method. ,- ; · ·Anar!ist!"'"--.-r-'AWal~sis Dae;~.~.:; .MRL:" ': -,J Arsenic 0.007 mg/L EPA20D.9 bselstedt 2/19/2015 0.002mg/L

Bicarbonate as CaC03 <1.00 mg/L SM2320B 1 mg/L

Calcium 73.7 mg/L EPA2D0.7 mamundson 2/17fl015 1 mg/L

Carbonate as CaC03 <1.00 mg/L SM 23206 1 mg/L

ChlO<ic!e 3,92 mgll. EPA300.0 mamundson 211 1/2015 2mg/L

Condudlvlty 467 uS/cm SM 2510 B bsefstedt 2/10/2015 uS/crn

Fluoride 0,791 mg/L EPA300.0 mamundson 2111/20 15 0.2mg/l.

Hydroxide as CaC03 <1.00 mg/L SM2320B 1 mg/L

Iron <0.020 mg/I. EPA200.7 mamundson 2/17/201 5 0.02 mg/L

Magnesium 14.6 mg/I. EPA 200.7 mamundson 2117/2015 1 mg/L

Man9on~3c, <0.020 mg/I. Cl'A 200. 7 mamund~on 2/17/2015 0 ,0 2 111~/L

Nitrate-Nitrite as N <0.20D mg/I. EPA 300.0 mamundson 2/1 1/2015 0.2 mg/L

pH 7.1 SU SM4500-H B bselstedt 2/10/2015 osu Phenolphthalein as CaC03 <1.00mgll. SM2320B 1 mg/I.

Potassium 2.27 mg/L EPA 200.7 rnamundson 2/17/2015 1 mg/L

Sodium 2.69 mg/I. EPA 200.7 mamundson 2/17/2015 1 mg/L

Sulfate 19.7 mg/L EP.A 300.0 mamundson 2/11/2015 2mg/L

Total Alkalinity as CaC03 <1.00 mg/I. SM 2320B 1 mg/I.

Total Dissolved Solids (TDS) 300mg/L SM 2540C kjirava 2/12/2015 2.5 mg/L

Total Hardness as CaC03 245 mg/L EPA200.7 mamtmdson 2/17/2015 2mg/L

Turtlldlty 0.122 NTU EPA 160.1 bsolstodt 2/10/2015 0.01 NTU

Approved By: ~ '---- . Date: b'5 - fJ..J - l~ •The MRL is the sma~ s red ~ lion of a Mibstance thal can be relably meawrcd by an a,,;JyUcal method. Values bekiw th!s level aco raportud as 4 fess-!han (<)" whon an analyfo eitho, is nol dc!t,cled o, is delecfod at a concentraUon less than the MRL. Not all anatyses Will have an appUcable MRL

F-3

Table F-3: January 2016 Laboratory Results for Treated Water for SEWUD-East

0

c. fll-~~ SEWUD-CetltP&l PO Box 10 Mantador, ND 58058

Attention:

Lal>Sampte ID: 15_120702-05

Report of Analysis

Ccnvnenl

Project ID:

Fargo Cass Public Health Environmental L.aboralO<y

435 141h Avenue South

Fargo, ND 58103

Phone: (701)-298-6986

Fax: (701)-241-8110

Email: SEWU@RRT.NET

Colo<Uon Date: 1114/2016

Sita: Train A l ocation:

I.ab Sample ID; 15_120702,08

site, Train B

ABenic 0.008mg/L

ColloctlOfl Dale: 111412016

LocaUon:

EPA20.0.9 bsel&tedt 112212016

Date: _n.L-J-1.,,.,8..._-....,,J 6'----

ThA mll•lon ot Farvo cas& Public tioalth la to asswe a hollly community for al peOl)lo through on-going as11011monl, educaU011, advocacy, intertonllon, prevention, end colleborallon. F~

F-4

Table F-4: January 2017 Laboratory Results for Treated Water for SEWUD-East

Public Health f' T<!.•Vt"fll , l'r4ITHi H'. !'r<i lNt.

,ll"t,-6 ·c,.~.-P~bti~~.--i;..s;.1~.

SEWUD-East PO Box 10 Mantador, ND 58058

Attention:

Lab Sample ID: 17_011004-01

Site:

l_Analyte ..'.:.,· Arsenic

Bicarbonate as CaC03

Calcium

Carbonate as CaC03

Chloride

Conductivity

Fluoride ·

Hydroxide as CaC03

Iron

Magnesium

Manganese

Nitrate-Nitrite as N

pH

Phenolphthalein as CaC03

Potassium

Sodium

Sulfate

Total Alkalinity as CaC03

Total Dissolved Solids (TDS)

Total Hardness as CaC03

Report of Analysis

Fargo Cass Public Health Environmental Laboratory

435 14th Avenue South

Fargo, ND 58103

Phone: (701 )-298-6986

Fax: (701)-241-8110

..... . . · -Sample Result_~----0.008 mg/L

234 mg/L

73.6 mg/L

<1.00 mg/L

5.63 mg/L

463 uS/cm .

0 .969 mg/L

<1.00 mg/L

<0.020 mg/L

15.1 mg/L

<0.020 mg/L

<0.200 mg/L

7.2SU

<1.00 mg/L

1.89 mgll

2.71 mg/L

29.2 mgll

234 mg/L

298 mg/L

246 mg/L

Comment

Project ID:

Email: SEWU@RRT.NET

Collection Dale: 1/10/2017

Location:

Method C' ; ,2-..c. Analyst:".:: .. :. Analysis Date ·~,~ · .. :l MRl:!~,ilid EPA 200.9 bselstedt 1/11/2017 0.002 mg/L

SM 2320B kjirava

EPA 200.7 bselstedt

SM 2320B kjirava

EPA300.0 bselstedt

SM 2510 B bselstedt

EPA 300.0 · bselstedt ·

SM 2320B kjirava

EPA 200.7 bselstedt

EPA 200.7 bselstedt

EPA 200.7 bselstedt

EPA 300.0 bselstedt

SM 4500-H B bselstedt

SM 2320B kjirava

EPA 200.7 bselstedt

EPA 200.7 bselstedt

EPA 300.0 bselstedt

SM 2320B kjirava

SM 2540 C kjirava

EPA200.7 bselstedt

1/11/2017

1/12/2017

1/11/2017

1/10/2017

1/10/2017

1/10/2017

1/11/2017

1/12/2017

1/12/2017

1/12/2017

1/10/201 7

1/10/2017

1/11/2017

1/12/2017

1/12/2017

1/10/2017

1/11/2017

1/11/2017

1/12/2017

1 mg/L

1 mg/L

1 mg/L

2mg/L

uS/cm

0.2 mg/L

1 mg/L

0.02 mg/L

1 mg/L

0.02 mg/L

0.2 mg/L

osu 1 mg/L

1 mg/L

1 mg/L

2 mg/L

1 mg/L

2.5 mg/L

2mg/L

Turbidity /1/J; 0.070~T EPA 180.1 bselstedt 1/10/2017 0.01 NTU

Approved s~d/Jif:L _ _ ___ ___ Date: J) \ - ) ~:11~--"The MRL is the smallest measured concen ation o a substance that can be reliably measured by an analyhcal method. Values below this level are reported as "less-than (<)' when an analyle either is not detected or is detected al a concentration less than the MRL. Nol all analyses will have an applicable MRL.

The mission of Fargo Cass Public Health is to assure a healthy community for all people through on-going assessment, education, advocacy, intervention, prevention, and collaboration.

Page 1 of 1

Far_'rHo ~

F-5

Table F-5: January 2018 Laboratory Results for Treated Water for SEWUD-East

Report of Analysis

Fargo Water Treatment Plant Environmental Laboratory

435 14th Avenue South

Fargo, NO '58103

Phone: (701)-298-6986

Fax: (701)•24f-ll110

SEWUD ~'3,

PO Box 10 Comment

Mantador, ND 58058 Pro1oct ID:

Attention: Email: SEWU@RRT.NET

Lob Somplo ID: 18 012404-10 Colloction O.te: 112312018

Sita: ri ,./1-sk'J) .._ ... , .llll•l~to . · : ,

. • l • . ~ : ,-.--• ••, . ·· . • .,. §gmglc B21Y[1' .·. . Mctho.d •.. ; .: · ATlolH1·• Analysis batr, . . . . MR~•

Arsenic 0.006m9/I. EPA200.8 bsehttcdt 112512010 0.002 m(J/L

Bioa<bonate as CaC03 234mg/l. SM23208 I\Prava· 1fl41'20f8 f mg/L

Calcium 80.0mgll EPA200.7 b<lolutodl 1 fl'4/2018 'mg/I.

Carbonate no CaC03 <1.00 mgA. SM2320D ,kjlrova 1/2412018 1 mg/L

Chloride 5.78mg/l EPA300.0 maahr 1fl4fl018 2mg/L

C onduclivlly 498 uS/cm SM25108 ·-

..,,,...,, 1fl4fl018 uSlcm

Fluoride 0.872mgn. EPA300.0 ' mRohr 112412018 0.2 mg/L

Hytloxide as CoC03 <1.00 mg/I. SM2320B lcjlrevo 1/24fl018 1 mgll

Iron <0.020 mg/I. EPA200.7 bscl8lodt 1fl4/2018 0.02mgll

Magnesium 16.1 mg/L EPA200,7 bselstodt 1124/2018 1 mg/L

Manganese <0.020mg/L EPA200.7 baololodl 112412018 0.02 mgll

Ni1nllttlltrl!casN <0.200mg/l EPA!lOO.O msnhr 1124"!018 02mgll.

pH 7.4 SU SM 4500•H B kjlrava 1124/2018 osu

Phenolphlhal ein as CaC03 <1.00 mg/l SM23208 k~rova 1/2412018 1 mg/l

Potassill'l'I 2.29mgll EPA200.7 bsftlatedt 1fl5fl018 I mg/I.

Sodium 3.39mg/L EPA 200,7 bsolstedt 1/24/2018 1 mg/L

Sulfale 39.5 mg/I. EPA300,0 msahr 112412018 2mg/L

Total Al<allrily 88 CaC03 234mgll SM23200 l<flrevo 1/2412018 1 mgll

Tola! Dissolv ed Solids (TOS) 328 mg/L SM2540 C kjlrova 1/211/2018 2.5 mg/L

Total Hardnoss as CaC03 266mg/L EPA 200.7 bsolslool 1/2412018 2 1119/L

Turbicflly 0.060 NTIJ EPA 180.1 l<jnva 1/24fl018 0.01 NlV

A-., ~iti lJ:f .... 01-01-\B "The MRL II ltlo i;m;iHest 1ne"ured concentration of o MibtJtonoo that <:an bu .-eli~bly mo113ured by an analytical method. Values bfllow !hi$ leve4 are

reported a1 "l@11a-than (<)" whon M ana.lyto either is not dol&cled ot Is dotoctod at a ooncentralkm lct\s lhon the MRL. Nol all analyiio, win have on

Ol)lllcablo 1~1\L.

G-1

APPENDIX G – SITE INSPECTION CHECKLIST

FIVE-YEAR REVIEW SITE INSPECTION CHECKLIST

I. SITE INFORMATION

Site Name: Arsenic Trioxide Date of Inspection: 05/22/2018

Location and Region: Ransom, Richland and Sargent Counties, ND/Region, Region 8 EPA ID: NDD980716963

Agency, Office or Company Leading the Five-Year Review: EPA Region 8 Weather/Temperature: 80s and Sunny

Remedy Includes: (Check all that apply) Landfill cover/containment Monitored natural attenuation Access controls Groundwater containment Institutional controls Vertical barrier walls Groundwater pump and treatment Surface water collection and treatment Other:

Attachments: Inspection team roster attached Site map attached

II. INTERVIEWS (check all that apply) 1. O&M Site Manager Brian Bergantine

Name Operations Manager Title

06/05/2018 Date

Interviewed at site at office by phone Phone: Problems, suggestions Report attached:

2. O&M Staff Name

Title

mm/dd/yyyy Date

Interviewed at site at office by phone Phone: Problems/suggestions Report attached:

3. Local Regulatory Authorities and Response Agencies (i.e., state and tribal offices, emergency response office, police department, office of public health or environmental health, zoning office, recorder of deeds, or other city and county offices). Fill in all that apply.

Agency NDDoH Contact Carl Andersen

Name Project Manager Title

6/04/2018 Date

701-328-5213 Phone No.

Problems/suggestions Report attached: Agency SEWUD Contact Steve Hansen

Name General Manager Title

05/22/2018 Date

701-242-7432 Phone No.

Problems/suggestions Report attached:

4. Other Interviews (optional) Report attached:

III. ON-SITE DOCUMENTS AND RECORDS VERIFIED (check all that apply)

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1. O&M Documents

O&M manual Readily available Up to date N/A

As-built drawings Readily available Up to date N/A

Maintenance logs Readily available Up to date N/A

Remarks:

2. Site-Specific Health and Safety Plan Readily available Up to date N/A

Contingency plan/emergency response plan

Readily available Up to date N/A

Remarks:

3. O&M and OSHA Training Records Readily available Up to date N/A

Remarks:

4. Permits and Service Agreements

Air discharge permit Readily available Up to date N/A

Effluent discharge Readily available Up to date N/A

Waste disposal, POTW Readily available Up to date N/A

Other permits: North Dakota State permit to operate water treatment plant.

Readily available Up to date N/A

Remarks:

5. Gas Generation Records Readily available Up to date N/A

Remarks:

6. Settlement Monument Records Readily available Up to date N/A

Remarks:

7. Groundwater Monitoring Records Readily available Up to date N/A

Remarks:

8. Leachate Extraction Records Readily available Up to date N/A

Remarks:

9. Discharge Compliance Records

Air Readily available Up to date N/A

Water (effluent) Readily available Up to date N/A

Remarks:

10. Daily Access/Security Logs Readily available Up to date N/A

Remarks:

IV. O&M COSTS

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1. O&M Organization

State in-house Contractor for state

PRP in-house Contractor for PRP

Federal facility in-house Contractor for Federal facility

SEWUD pays for the O&M costs. Costs are not separable from normal operation costs.

2. O&M Cost Records

Readily available Up to date

Funding mechanism/agreement in place Unavailable

Original O&M cost estimate: Breakdown attached

Total annual cost by year for review period if available

From: mm/dd/yyyy Date

To: mm/dd/yyyy Date

Total cost

Breakdown attached

From: mm/dd/yyyy Date

To: mm/dd/yyyy Date

Total cost

Breakdown attached

From: mm/dd/yyyy Date

To: mm/dd/yyyy Date

Total cost

Breakdown attached

From: mm/dd/yyyy Date

To: mm/dd/yyyy Date

Total cost

Breakdown attached

From: mm/dd/yyyy Date

To: mm/dd/yyyy Date

Total cost

Breakdown attached

3. Unanticipated or Unusually High O&M Costs during Review Period Describe costs and reasons: None

V. ACCESS AND INSTITUTIONAL CONTROLS Applicable N/A

A. Fencing

1. Fencing Damaged Location shown on site map Gates secured N/A Remarks:

B. Other Access Restrictions

1. Signs and Other Security Measures Location shown on site map N/A Remarks: Pump houses and waste treatment plant locked, secured and located in a rural area.

C. Institutional Controls (ICs)

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1. Implementation and Enforcement Site conditions imply ICs not properly implemented Yes No N/A Site conditions imply ICs not being fully enforced Yes No N/A Type of monitoring (e.g., self-reporting, drive by): State is responsible for reviewing institutional controls Frequency: Quarterly Responsible party/agency: NDDoH

Contact Carl Anderson 06/04/2018 701-328-5213

Name Title Date Phone no.

Reporting is up to date Yes No N/A

Reports are verified by the lead agency Yes No N/A

Specific requirements in deed or decision documents have been met Yes No N/A

Violations have been reported Yes No N/A

Other problems or suggestions: Report attached

See institutional control review in Section II.

2. Adequacy ICs are adequate ICs are inadequate N/A Remarks: See institutional control review in Section II.

D. General

1. Vandalism/Trespassing Location shown on site map No vandalism evident Remarks:

2. Land Use Changes On Site N/A Remarks:

3. Land Use Changes Off Site N/A Remarks:

VI. GENERAL SITE CONDITIONS

A. Roads Applicable N/A

1. Roads Damaged Location shown on site map Roads adequate N/A Remarks:

B. Other Site Conditions

Remarks:

VII. LANDFILL COVERS Applicable N/A

VIII. VERTICAL BARRIER WALLS Applicable N/A

IX. GROUNDWATER/SURFACE WATER REMEDIES Applicable N/A

A. Groundwater Extraction Wells, Pumps and Pipelines Applicable N/A

1. Pumps, Wellhead Plumbing and Electrical

Good condition All required wells properly operating Needs maintenance N/A

Remarks:

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2. Extraction System Pipelines, Valves, Valve Boxes and Other Appurtenances

Good condition Needs maintenance

Remarks:

3. Spare Parts and Equipment

Readily available Good condition Requires upgrade Needs to be provided

Remarks:

B. Surface Water Collection Structures, Pumps and Pipelines Applicable N/A

1. Collection Structures, Pumps and Electrical

Good condition Needs maintenance

Remarks:

2. Surface Water Collection System Pipelines, Valves, Valve Boxes and Other Appurtenances

Good condition Needs maintenance

Remarks:

3. Spare Parts and Equipment

Readily available Good condition Requires upgrade Needs to be provided

Remarks:

C. Treatment System Applicable N/A

1. Treatment Train (check components that apply)

Metals removal Oil/water separation Bioremediation

Air stripping Carbon adsorbers

Filters:

Additive (e.g., chelation agent, flocculent): When needed, ferric coagulant added to co-precipitate arsenic if iron in groundwater is not high enough.

Others:

Good condition Needs maintenance

Sampling ports properly marked and functional

Sampling/maintenance log displayed and up to date

Equipment properly identified

Quantity of groundwater treated annually:

Quantity of surface water treated annually:

Remarks:

2. Electrical Enclosures and Panels (properly rated and functional)

N/A Good condition

Needs maintenance

Remarks:

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3. Tanks, Vaults, Storage Vessels

N/A Good condition

Proper secondary containment Needs maintenance

Remarks:

4. Discharge Structure and Appurtenances

N/A Good condition

Needs maintenance

Remarks:

5. Treatment Building(s)

N/A Good condition (esp. roof and doorways)

Needs repair

Chemicals and equipment properly stored

Remarks:

6. Monitoring Wells (pump and treatment remedy)

Properly secured/locked Functioning

Routinely sampled Good condition

All required wells located Needs maintenance N/A

Remarks:

D. Monitoring Data

1. Monitoring Data

Is routinely submitted on time Is of acceptable quality

2. Monitoring Data Suggests: N/A

Groundwater plume is effectively contained Contaminant concentrations are declining

Remarks: Monitoring data collected by SEWUD show that arsenic is below the MCL in treated groundwater.

E. Monitored Natural Attenuation 1. Monitoring Wells (natural attenuation remedy)

Properly secured/locked Functioning Routinely sampled Good condition

All required wells located Needs maintenance N/A

Remarks:

X. OTHER REMEDIES If there are remedies applied at the site and not covered above, attach an inspection sheet describing the physical nature and condition of any facility associated with the remedy. An example would be soil vapor extraction.

N/A XI. OVERALL OBSERVATIONS

A. Implementation of the Remedy Describe issues and observations relating to whether the remedy is effective and functioning as designed. Begin with a brief statement of what the remedy is designed to accomplish (e.g., to contain contaminant plume, minimize infiltration and gas emissions). The remedy is effectively removing arsenic from raw water through the use of a ferric coagulant and filters to reduce arsenic concentrations in treated water below the MCL.

B. Adequacy of O&M

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Describe issues and observations related to the implementation and scope of O&M procedures. In particular, discuss their relationship to the current and long-term protectiveness of the remedy. SEWUD has not observed any issues related to the O&M procedures.

C. Early Indicators of Potential Remedy Problems Describe issues and observations such as unexpected changes in the cost or scope of O&M or a high frequency of unscheduled repairs that suggest that the protectiveness of the remedy may be compromised in the future. None.

D. Opportunities for Optimization Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy. Optimizations include upgrading pumps with more energy-efficient models as well as automating the backwash system.

H-1

APPENDIX H – SITE INSPECTION PHOTOS

SEWUD building and site information repository in Mantador, North Dakota

Geothermal unit inside the SEWUD building

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H-2

Emergency generator for the geothermal unit outside the SEWUD building

SEWUD- East water treatment plant building and emergency generator

H-3

Interior of SEWUD-East water treatment plant

SEWUD-East wellhead protection area and a production well

H-4

Reservoir G building

Control panel in Reservoir G building

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Hankinson Reservoir building

Monitoring system inside Hankinson Reservoir building

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Reservoir N building

Interior of Reservoir N building