REM IV Remedial Planning Activities at Selected Uncontrolled Hazardous Waste Sites-Zone

SFUND RECORDS CTR

0217-00024

SFUND RECORDS CTR

88004692

^ Environmental Protection Agency ^ I f !^ Hazardous Site Control Division

Contract No. 68-01-7251

TECHNICAL MEMORANDUM RESULTS OF

THE PGA SOILS INVESTIGATION

PHOENIX-GOODYEAR AIRPORT RI/FS

WA No. 3 0 - 9 L 1 9 . 0

O c t o b e r 5 , 198 7

a^HILL Black & Veatch ICF PRC Ecology and Environment

TECHNICAL MEMORANDUM RESULTS OF

THE PGA SOILS INVESTIGATION

PHOENIX-GOODYEAR AIRPORT RI/FS

WA No. 30-9L19.0

October 5, 1987

NONDISCLOSURE STATEMENT

This document has been prepared for the U.S. Environmental Protection Agency under Contract No. 68-01-7251. The mate­rial contained herein is not to be disclosed to, discussed with, or made available to any person or persons for any reason without the prior express approval of a responsible official of the U.S. Environmental Protection Agency.

Page

CONTENTS

Introduction Purpose and Scope Selection of Analytical Parameters Selection of Sampling Locations

VOC Sampling Locations Pesticide Sampling Locations Chromium Sampling Locations

Archive Samples Background Soil Sampling Locations

Sampling Methods Backhoe Test Pits for Pesticides and Chromium Hand-Augered Samples for Pesticides Soil Borehole Drilling

Deviations from the Soil Sampling Plan Field Effort Changes Laboratory Analytical Procedure Changes

Results Background Sites VOC Borings Pesticides Metals Chromium

Future Analyses

TABLES

1 ADEQ-Suggested Health-Based Cleanup Levels for Contaminants in Soils

2 Analytical Methods for PGA Soil Samples

3 Criteria for Analyzing Archive Samples

4 Pesticide Concentrations from Background Sampling Locations

5 Chromium Concentrations from Background 2 3 Sampling Locations

6 Concentrations of Metals from Background 24 Sampling Locations

7 TCE Concentrations in Soil 28

8 Pesticide Concentrations from the Hangar 29 Apron Area

1 2 3 6 6 6 8 10 11 12 12 13 14 17 17 19 20 21 27 27 30 31 37

Page

4

5

11

22

RD/R91/043-2

CONTENTS (Continued)

TABLES (continued) Page

9 Pesticide Concentrations in Sediments Derived 30 from the Airport Drain Ditch

10 Metal Concentrations from the GAC Sludge 32 Drying Beds

11 Chromium Concentrations from GAC Sludge 35 Drying Bed No. 1

12 Chromium Concentrations from GAC Sludge 36 Drying Bed No. 2

13 Chromium Concentrations from Former Sewage 38 Treatment Facility

14 Chromium Concentrations Along the Course of 38 the Airport Drain Ditch near the Outfall of Drain 001

15 Chromium Concentrations from the Former Paint 3 9 Tent Area

16 Chromium Concentrations from the Hangar Apron 39 Area

Follows FIGURES Page

1 Site Location Map ^

2 General Soil Sampling Areas of PGA (located at end of report)

3 VOC Boring Locations and Pesticide Sampling Locations of Sediments from the Airport Drain Ditch (located at end of report)

4 Soil Sampling Locations Near the Airport ( Hangars and Former Paint Tent

5 Pesticide Sampling Locations of Sediments Derived from the Airport Drainage Ditch

6 Soil Sampling Locations at the Former GAC ! Sludge Drying Beds

RD/R91/043-3

CONTENTS (Continued)

Follows FIGURES (continued) Page

7 Soil Boring Locations at the Former PGA 8 Sewage Treatment Facility

8 Soil Boring Locations in the Former Airport 8 Drain Ditch Near the Outfall of Drain 001

9 Background Soil Sampling Locations (located at end of report)

RD/R91/043

RD/R91/043-4

TECHNICAL MEMORANDUM

PREPARED BY:

DATE:

RE:

PROJECT:

DISTRIBUTION;

John Lucero and Jess Brown, CH2M HILL/RDD

October 5, 1987

Results of the PGA Soils Investigation

W63600.FT

EPA RPM—Jeff Rosenbloom PGA Technical Committee Nancy Lindsay, U.S. EPA, Region IX Randall Kaltreider, U.S. EPA, Headquarters CH2M HILL QA Reviewers—Terry Foreman/LAO, Mike Kemp/GNV, and Bob Schilling/RDD Site Manager—John Lucero/RDD Peter Mock/CH2M HILL, PHX Fritz Carlson/CH2M HILL, RDD Mike Smith/CH2M HILL, RDD Jess Brown/CH2M HILL, RDD Steve Hahn/CH2M HILL, SFO Jane Fisher/CH2M HILL, SFO Steve Franks/CH2M HILL, RDD Vicki Kohonoski/CH2M HILL, WDC Beth Baruth/CH2M HILL, DEN Don Huff/Black & Veatch

INTRODUCTION

This technical memorandum summarizes the results obtained from the analyses of soil samples collected from various locations at the Phoenix Goodyear Municipal Airport (air­port) and from the former Goodyear Aerospace Corporation (GAC) facility from June 23 to July 28, 1987. This memo­randum also summarizes deviations from field or laboratory procedures described in the Phoenix-Goodyear Airport Soil Sampling Plan.

These data will be used for interpreting the degree and extent of contamination, and to assess the potential adsorp­tion or mobility of the compounds of interest. The results of these interpretations will be discussed in a future soils interpretation technical memorandum.

CH2M HILL. Soil Sampling Plan Phoenix-Goodyear Airport RI/FS. Prepared for U.S. EPA, Toxics and Waste Management Division, REM/FIT, Contract No. 68-01-6692. June 29, 1987,

RD/R91/040

The Phoenix-Goodyear Airport Superfund site (PGA) is located in the Salt River Valley approximately 20 miles west of Phoenix, Arizona. The study area encompasses approximately 42 square miles of agricultural, industrial, and municipal property within the Cities of Goodyear, Avondale, and Phoenix (Figure 1). The climate is characterized by long, hot summers and short, mild winters. The average annual precipitation is approximately 7.5 inches per year. Vegeta­tion in nonirrigated undeveloped areas is very sparse, but there are many areas of irrigated agricultural lands to the north, west, and east of the study area.

PURPOSE AND SCOPE

The primary objective of the PGA soils investigation was to define the vertical extent of the contaminants that had been identified at the PGA site during previous investigations. The sampling effort was also intended to satisfy the data needs to develop a detailed work plan outline for a future feasibility study.

Specific objectives of the PGA soils investigation were as follows:

o Assess the vertical extent and degree of contami­nation by volatile organic compounds (VOC's) at the airport and GAC.

o Assess the vertical extent of contamination of chromium at suspected source areas.

o Collect an adequate number of soil samples from representative soil taxa near the PGA site to quantify background contaminant concentrations.

o Assess if the site's soils contain contaminant concentrations in excess of the Arizona Department of Environmental Quality's (ADEQ, formerly the Arizona Department of Health Services) suggested health-based soil action levels.

o Examine other soil properties that may influence the adsorption or mobility of soil contaminants.

o Assess the degree of contamination by pesticides at suspected locations at the airport.

2 Ecology and Environment. Source Verification Field Investigation. Prepared for U.S. EPA, Toxics and Waste Management Division, REM/FIT, Contract No. 68-01-6692. January 31, 1986.

RD/R91/040

F I G U R E 1

SITE LOCATION MAP

P H O E N I X - G O O D Y E A R AIRPORT SOILS I N V E S T I G A T I O N

W 6 3 6 0 0 . F T O C T O B E R 1 9 8 7

o Assess whether the potential soil contamination is a continuing source of groundwater contamination.

The scope of this field investigation included the following elements:

o The collection of soil samples for VOC analysis from 22 soil boring locations situated at the air­port and the former GAC facility

o The collection of soil samples for total chromium analyses from 15 soil boring locations located at the airport

o The excavation and collection of soil samples from 14 backhoe test pits plus the collection of 8 com­posite sediment samples for pesticide analyses

o The collection of soil samples for total chromium and additional metals analyses from 12 backhoe test pits at the former GAC facility

o The collection of representative background soil samples from eight backhoe test pits for pesti­cides, chromium, and additional metals analyses

For ease of discussing sampling locations and to provide an overview of the sampling areas, refer to Figures 2 and 9, located at the end of the report.

SELECTION OF ANALYTICAL PARAMETERS

The analytical parameters selected were based on the find­ings of previous investigations conducted at the airport and the former GAC facility. Previous investigations identified a number of VOC's, EPA priority pollutant metals, and pesti­cides. The soil contaminants that had been previously iden­tified at the site and were suspected of exceeding the ADEQ suggested health-based soil action limits are trichloroethene (TCE), isomers of dichloroethene (1,1-DCE and 1,2-DCE), 1,1,1-trichloroethane (1,1,1-TCA), perchloroethene (PCE), 1,l-dichloro-2,2-bis[p-chlorophenyl]-ethene (4-DDE'], l,l,l-dichloro-2,2-bis[chlororphenyl]-ethane (4-DDT'), aluminum, and chromium.

Table 1 shows the health-based cleanup levels for contami­nants in soils suggested by ADEQ.

Other organic compounds that had been previously identified in groundwater samples and were evaluated during this inves­tigation were chloroform, carbon tetrachloride, and methy­lene chloride. Vinyl chloride was also added to the list of

RD/R91/040

Table 1 ADEQ-SUGGESTED HEALTH-BASED CLEANUP LEVELS

FOR CONTAMINANTS IN SOILS^

TCE 1,1-DCE 1,2-DCE 4-DDE' 4-DDT' Chromium Aluminum Arsenic Barium Cadmium Copper Nickel Lead Mercury Zinc PCE 1,1,1-TCA

0.26 to 0.32 mg/kg 0.70 mg/kg ,0.70 mg/kg 1.0 mg/kg 1.0 mg/kg

1,500 mg/kg 15.0 mg/kg 100 mg/kg

5,000 mg/kg 1.0 mg/kg 300 mg/kg 700 mg/kg 700 mg/kg 5.0 mg/kg

2,000 gg/kg

b

As reported by ADEQ,

ADEQ did not provide information on 1,1,1-TCA and PCE action limits.

organic analytical parameters because it is a degradation product of TCE. Additional metals selected for analysis were arsenic, barium, cadmium, copper, lead, mercury, mangan­ese, nickel, and zinc. These additional metals were selected to gather the data necessary to evaluate potential exposure levels for the PGA Public Health Endangerment Assessment.

The analytical parameters are grouped into four analytical suites:

o Suite 1—VOC's o Suite 2—Metals o Suite 3—Chromium o Suite 4—Pesticides

The analytical parameters, methods, and where applicable, the detection limits for each analytical suite are shown in Table 2.

RD/R91/040

Table 2 ANALYTICAL METHODS FOR PGA SOIL SAMPLES

Parameter

SUITE 1—VOC'S

Vinyl Chloride Methylene Chloride 1,1-dichloroethene trans-1,2-dichloroethene Chloroform 1,1,1-Trichloroethane Carbon Tetrachloride •Trichloroethene Tetrachloroethene High Level Methanol Extraction

SUITE 2—METALS

Aluminum Arsenic Barium Cadmium Copper Lead Manganese Mercury Nickel Zinc

SUITE 3—CHROMIUM

Total Chromium

SUITE 4—PESTICIDES

4-DDE' 4-DDT'

EPA Method^

8010 8010 8010 8010 8010 8010 8010 8010 8010 5030

3010/201.1^ 7061 7080 7130 7210 7420 7460 7471 7520 7950

Detection Limit

{mq/kq)

0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 N/A

4.0 0.1 4.0 0.4 0.8 2.0 0.4 0.05^ 2.0 0.8

7190

8080 8080

0.8

0.01 0.01

U.S. Environmental Protection Agency, 1979, Methods for Chemical Analysis of Water and Wastes, EPA-600/4-79-020, Revised March 1983.

, 1982, Test Methods for Evaluating Solid Wastes, Physical/Chemical Methods, SW-846, revised April, 1984.

'Mercury's detection limit is contingent on the volume of digestion solution used. 10 ml of digestion solution to 0.2 g of soil results in a 0.05 mg/kg detection limit, but if 5 ml of digestion solution is added to 0.2 g of soil, the detection limit is 0.11 mg/kg. A smaller volume of , solution may be used to limit the frothing of the solute to avoid the potential volatilization of mercury.

RD/R91/040

SELECTION OF SAMPLING LOCATIONS

VOC SAMPLING LOCATIONS

Nineteen soil borings were sampled at 5-foot intervals to a depth of 6 5 feet or until the groundwater table was encoun­tered. Fifteen of these locations corresponded to previous soil gas sampling locations where the concentration of VOC's, primarily TCE, was equal to or greater than 10 yg/l. This threshold concentration level was believed to be indi­cative of contaminant source areas. The remaining four borings were completed around the large hangar apron area and at the former location of the Navy's aircraft washracks (Figure 3). These additional locations were selected to determine if the former washrack area is a source of VOC and chromium contamination, since the samples collected from these borings were analyzed for both VOC's and total chromium.

Additional soils data to assess the contamination by VOC's were needed to determine if the PGA soils are a continuing source of groundwater contamination or if they are contami­nated to the extent that they exceed the ADEQ soil action limits.

PESTICIDE SAMPLING LOCATIONS

Soil samples were collected from three different areas at the airport to characterize the degree of soil contamination from the pesticides 4-DDE' and 4-DDT'. These samples were collected because background samples from the source verification investigation contained these pesticides at concentrations near the ADEQ action limits.

Based on personal communication with ADEQ representatives, the western portion of the Salt River Valley historically received frequent applications of DDE and DDT to suppress pink bole worm in cotton, and the ADEQ has found that where sediments have been dredged from irrigation ditches, the sediments have contained elevated levels of pesticides. In addition to the potential contamination from dredged sedi­ments, it was determined that areas used by crop dusting aircraft should also be sampled.

The three areas sampled for pesticide contamination were as follows:

o The dredged sediments along the course of the airport ditch (Figure 3)

o The area adjacent to the southeast side of the concrete apron of the large hangars (Figure 4)

RD/R91/040

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F I G U R E 4

SOIL SAMPLING L O C A T I O N S NEAR THE AIRPORT HANGARS

t AND FORMER PAINT TENT

PHOENIX G O O D Y E A R AIRPORT

I S O I L S I N V E S T I G A T I O N

W 6 3 6 0 0 . F T O C T O B E R 1 9 8 7

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o The extreme southwestern end of the airport property where the sediments dredged from the airport drain ditch have been disposed of by airport personnel (Figure 5)

These locations are each approximately 2,500 feet away from the location of the sample point of the background sample that contained 4-DDE' and 4-DDT', but based on the past historical use of the airport, these locations appeared to be the most logical areas to sample.

At each location where dredged sediments were sampled, both along the airport ditch and at the southwestern airport fill area, the cuttings collected from augering through the sedi­ments were composited from a depth of 0 to 60 inches or from the top of the sediment pile to the original ground surface, whichever was shallower. These sediments were suspected of containing elevated levels of pesticides since they are the result of runoff and subsequent erosion of agricultural lands that have historically received pesticide applications.

Airport Ditch

Composite soil samples were collected at four locations from the sediments dredged from the airport drain ditch that lies to the west of the runway (Figure 3) with a hand auger to a depth of about 5 feet at approximately 500-foot intervals along the course of the ditch.

Hangar Apron Area

The area southeast of the hangar apron area is the only area identified by airport personnel which has been used by crop dusting aircraft, and this area potentially receives surface runoff from the apron area. Near the hangar apron area, 14 sample locations were organized in a 200-foot grid pattern (Figure 4). This grid initiated at the southeastern edge of the apron and extended downslope toward the southeast. Soil samples were collected from backhoe test pits excavated to a depth of about 5 feet at the following depths such that the vertical distribution of the potential pesticide contamina­tion could be evaluated: 0 to 4 inches, 4 to 8 inches, 8 to 15 inches, and 15 to 30 inches.

Southwest Airport Fill Area

Composite soil samples were collected from four locations with a hand auger to a depth of about 5 feet at the loca­tions shown in Figure 5. This area is the airport's fill disposal area where sediments derived from the airport drain ditch have been periodically disposed of by airport personnel.

RD/R91/040

DATE OF PHOTOGRAPHY APRIL 1987

Nl I ' s l O O '

LEGEND

SAMPLING LOCATION

(05103 DENOTES FIELD DUPLICATE SAMPLES

F I G U R E 5

PESTICIDE SAMPLING LOCATIONS OF SEDIMENTS DERIVED FROM

I THE AIRPORT DRAINAGE DITCH

PHOENIX-GOODYEAR AIRPORT

SOILS INVESTIGATION

W63600.FT OCTOBER 1987

CHROMIUM SAMPLING LOCATIONS

Soil samples were collected from four different areas on both the former GAC facility and the airport property. The areas sampled were the two former sludge drying beds at GAC, the former sewage treatment facility at the airport, the former location of the airport drain ditch initiating from the outfall of GAC's Drain 001, and the location of the Navy's former paint tent. (See Figures 4, 6, 7, and 8.)

Former GAC Sludge Drying Beds

During the source verification investigation, the two GAC former sludge drying beds were sampled. The analyses for total chromium detected chromium at twice the ADEQ's action limit in the surface 0 to 1.5 feet at the smaller eastern bed, and a surface soil sample near the southwestern corner of the larger western bed contained chromium at a concentra­tion of 1,400 mg/kg. Since the sampling conducted during the source verification did not attempt to define the hori­zontal extent or vertical distribution of chromium contami­nation, additional soil sampling was necessary to facilitate the determination of the volume of soil potentially requiring remedial action.

Ninety-six soil samples were collected from the two former sludge drying beds: 48 samples from the larger western bed, and 48 samples from the smaller eastern bed (Figure 6). The samples were collected from backhoe test pits excavated to a depth of about 10 feet. Samples were collected from the following depths at each location: 0 to 4 inches, 4 to 8 inches, 8 to 15 inches, 15 to 30 inches, 30 to 45 inches, 45 to 60 inches, 60 to 90 inches, and 90 to 120 inches.

In addition to the samples collected for total chromium, samples were collected for the metals analytical suite at Locations 0601/0602, 0603, 0604, and 0608 from sludge bed No. 1, and at Locations 0701/0702, 0703, and 0705 from sludge bed No. 2. These additional samples were collected at 0 to 4 inches, 4 to 8 inches, and 8 to 15 inches. They were primarily collected to attain additional metals data for the study area's Public Health Endangerment Assessment, but they were also collected to assess the potential for surface soil contamination by other metals.

Former Airport Sewage Treatment Facility

This facility was in operation from 1951 until sometime after 1982. In 1952 the facility was upgraded to a secon­dary treatment facility, and industrial wastewater from the airport drain ditch was diverted to the facility for treat­ment. Since the Navy reportedly never used the air flota­tion system in its treatment of wastewater, essentially

RD/R91/040

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FIGURE 6

SOIL SAMPLING LOCATIONS AT THE FORMER GAC SLUDGE DRYING BEDS

' PHOENIX-GOODYEAR AIRPORT I

! . SOILS INVESTIGATION

W63600.FT OCTOBER 1987

DATE OF PHOTO

- ^ SAMPLING LOCATION

C10023 DENOTES FIELD DUPLICATE SAMPLES

F IGURE 7 SOIL BORING LOCATIONS

AT THE FORMER P.G.A. SEWAGE TREATMENT FACILITY

PHOENIX-GOODYEAR AIRPORT SOILS INVESTIGATION

W63600 .FT OCTOBER 1987

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untreated industrial wastewater was discharged from the bottom of the flotation tank to the airport ditch through an unlined channel (Ecology and Environment, 1986). The chemi­cal composition of the industrial wastewater is unknown, but in 1951 samples of this wastewater were collected, and based on their physical appearance, it was suspected that they contained chromates (Ecology and Environment, 1986). The facility is no longer present, but historical aerial photo­graphy was enlarged to a 1-inch to 500-foot scale such that the former facility could be located on current 1987 photography. The location of the treatment ponds and the unlined ditch which channeled wastewater into the airport ditch was determined from this historical photography.

Four soil borings were completed at the former location of the airport's sewage treatment facility. Two soil borings were placed at the location of the former filtration ponds, and the other two borings were placed along the course of the unlined channel which emptied into the airport drain ditch (Figure 7). The borings were completed before the groundwater table was encountered. Soil samples were collected at 5-foot intervals in brass sleeves with a California modified split-spoon sampler.

Former Airport Drain Ditch Near the Outfall of GAC Drain 001

Historically this drain ditch received industrial waste from the GAC facility under a National Pollutant Discharge Elimi­nation System (NPDES) permit. During the source verifica­tion investigation, the sewerlines at GAC which fed this ditch were sampled, and TCE and chromium were detected at 80,000 ppm and 1,587 ppm, respectively. Also during this investigation, soil borings were completed near the 001 out­fall point and at other locations spaced at very large intervals along the course of the ditch, but none of the soil borings were situated directly in the course of the former unlined ditch.

3 Aerial photography flown February 20, 1949 , clearly iden­tifies the original location of the unlined airport ditch. This photography was enlarged to a 1-inch to 500-foot scale and overlaid on 1987 photography to identify the historical location of the unlined drain ditch.

Four soil borings were completed along the historical course of the airport ditch. The first boring was located at the initial outfall point of GAC Drain 001, and the remaining locations were situated along the former ditch's route at

3 U.S. EPA. Aerial Photographic Analysis of a Hazardous Waste Study Area. Goodyear, Arizona. June 1983.

RD/R91/040

approximately 250-foot intervals (Figure 8). Soil samples were collected in brass sleeves with a California modified split-spoon sampler at 5-foot intervals to a depth of 65 feet or until the groundwater table was encountered.

Former Paint Tent

Three soil borings were completed at the vicinity of the former paint tent. Reportedly, chromic acid was used during the preparation of aircraft during painting operations. The location of the paint tent is still easily found, so borings were completed upslope, near the middle, and downslope from the pad where painting operations took place (Figure 4). Samples were collected at 5-foot intervals in brass sleeves with a California modified split-spoon sampler to an approx­imate depth of 40 feet or until the capillary fringe above the groundwater table was encountered.

ARCHIVE SAMPLES

Archive samples were collected at each sampling location and sampling depth for additional physical and chemical soil property tests. These analyses are being conducted on soil samples which contain contaminants near the ADEQ soil action limits. The results from these tests will be used in con­firming the site stratigraphy, and in evaluating soil pro­perties that may influence the adsorption or mobility of the contaminants being investigated. The following is a list of the physical and chemical soil property tests being conducted:

o Sodium acetate cation exchange capacity o Total organic carbon o Moisture content o Particle-size analysis o Extractable cations o Soil pH o Water soluble chromium elution tests

The archive samples for a given sample location will be analyzed if any of the previously analyzed samples collected from a given location are contaminated to the extent that they approach or exceed the ADEQ action limits. Table 3 presents the criteria for analyzing archive samples.

The intent of establishing these threshold concentration values was to allow for the characterization of the vadose zone. The concentration value for VOC's was established to provide data at all of the locations where suspected VOC contamination would be detected. The chromium concentration value was established to address the potential solubility of the suspected chromium contamination over a range of concen­tration values below the ADEQ's limit for total chromium.

RD/R91/040 10

Table 3 CRITERIA FOR ANALYZING ARCHIVE SAMPLES

Indicator Threshold Archive Sample Constituent Concentration

Soil Properties Any VOC 100 wg/kg Soil Properties 4'DDE or 4'DDT 0.8 mg/kg Soil Properties Chromium 500 mg/kg Soil Properties Aluminum 13 mg/kg

Percent moisture tests were conducted on all samples at the time of analysis for contaminants.

The aluminum and pesticide concentration values were estab­lished very close to their ADEQ action limits, such that the locations where these potential soil contaminants would be increasing towards or decreasing from the ADEQ limits could be investigated.

BACKGROUND SOIL SAMPLING LOCATIONS

This portion of the overall sampling effort was completed to determine the background contaminant concentrations for the suspected contaminants at PGA. The sampling of background locations was also completed to provide data for the public health endangerment assessment. Prior to this sampling effort there were insufficient data to determine if there are potential health risks associated with exposure to the site's soils.

Background soil samples were collected from eight offsite locations near the PGA site as shown in Figure 9. The loca­tions were selected on the basis of being representative of the principal soil taxa that occur at the PGA site, and the three major land uses adjacent to the site. Soil samples were collected for metals, pesticides, and soil properties in accordance with the methods described in this memorandum from the locations where the Laveen, Gilman, and Glenbar soils occur under agricultural, residential, and industrial land use. This matrix scheme was achieved for the respec­tive soils and the various land uses with the exception of the Glenbar soil in a residential setting. In this instance, a site which met this criterion could not be located. To alleviate this problem, a second location with the Laveen soil under residential land use was selected for sampling.

RD/R91/040 11

SAMPLING METHODS

Due to the different sampling techniques used during this field sampling effort, each sampling methodology used will be discussed according to the sampling technique or type of contaminant being investigated.

BACKHOE TEST PITS FOR PESTICIDES AND CHROMIUM

Soil samples were collected from backhoe test pits at back­ground locations, near the airport hangars, and at the locations of the former GAC sludge drying beds. To facili­tate viewing the soil profiles that were excavated, the pits were dug such that the length of the pit was parallel to the angle of the sun. While digging the pits, the backhoe con­tractor attempted to stockpile the excavated soil in piles that correspond to 2-foot intervals to facilitate replace­ment of the soil to its original location. Where soil samples were collected for pesticides, the pits were dug to a depth of about 5 feet; when samples were collected for chromium, the pits were excavated to a depth of about 10 feet (120 inches). Prior to any member of the sampling team entering a test pit, the backhoe subcontractor would place 7-foot aluminum hydraulic shoring devices in the pit at 4-foot centers to brace the sides of the pit such that it would be safe for members of the sampling team to enter the trench. At 10-foot test pit sites, the 7-foot shoring devices were placed 2 feet from the bottom of the trench, and the remaining 1 foot of soil was sloped back to the top of the shoring device.

After the test pit was adequately braced, the field soil scientist and one other team member entered the pit and collected samples in the following manner:

1. The soil scientist completed a soil profile description of the pit using National Cooperative Soil Survey (NCSS) abbreviations and terminology. Descriptions were completed at various sampling locations as outlined in the PGA Soil Sampling Plan (CH2M HILL, 1987).

2. The soil scientist then used a plastic-coated cloth tape to measure the required sampling depths along the side of the trench that was most repre­sentative of the soil profile. The sampling intervals were marked with pin flags that had been labeled with the appropriate depth measurement. The soil scientist then smoothed off the face of the pit with a clean trowel from the soil surface to the bottom of the pit and began sampling the pit at the lowest sampling depth and progressing upward.

RD/R91/040 12

3. To avoid cross contamination of samples, a small cavity was dug into the wall of the pit at the lower limit of the particular sampling depth sufficient in size to place the sample jar into. Then the soil scientist used another clean trowel to scrape a soil sample into the jar from above, taking care to avoid roots and excessive amounts of gravels. This step was repeated for every sample collected from each particular sampling depth.

4. After the soil scientist collected the samples for a given depth, the sample was given to the other team member to complete filling out the sample container label, decontaminate the sample con­tainer, package the samples, complete the neces­sary sample documentation, and place the samples in an ice cooler with frozen "Blue-Ice" packages.

5. When the sampling was completed for a given loca­tion, the backhoe operator removed the shoring devices and backfilled the pit according to the segregated piles of soil that were excavated during the digging of the pit.

HAND-AUGERED SAMPLES FOR PESTICIDES

Composite soil samples to be analyzed for pesticides were collected from the dredge piles adjacent to the airport drain ditch west of the runway, and at the extreme south­western end of the airport property where airport personnel have disposed of sediments dredged from the airport ditch and other fill material. Samples were collected at approxi­mately 500-foot intervals along the ditch, and approximately 250 feet apart at the fill disposal area. When the com­posite samples were collected, the following procedure was used:

1. The sampler selected a representative location directly adjacent to the ditch or near the edge of the fill disposal area for sampling. Once a representative location had been selected, the sampler used a decontaminated hand auger to auger a hole down through the sediments until the original ground surface was encountered or until the entire length of hand auger had been used. While augering, the sampler saved all of the cuttings on a clean plastic sheet.

2. After the sampler completed the augering, the cuttings were run through a sample splitter.

RD/R91/040 13

3. When the sample had been split, one portion of the split sample was placed in an 8-ounce sample jar for pesticide analysis and appropriately labeled. Then the sample was split again to attain a 16-ounce archive sample for physical and chemical soil property tests.

4. The remaining soil was placed back in the residual auger hole, and the plastic sheet was disposed of according to the procedures for disposal of gener­ated wastes described in the PGA Soil Sampling Plan (CH2M HILL, 1987) .

SOIL BOREHOLE DRILLING

Soil borings were completed at the former location of the airport sewage treatment facility, the former location of the airport drain ditch near the outfall of Drain 001, near the former paint tent, near the hangar apron and former wash-racks, and at the VOC boring locations where soil gas measurements appeared to be indicative of potential contami­nant source areas. A double-wall percussion air hammer was used to advance the boreholes and to obtain samples at 5-foot intervals with a 24-inch California modified split-spoon sampler. This method was selected because the tech­nology is well established for drilling in soils with a high content of coarse fragments, the method is quite rapid, and because a hollow stem auger rig could not perform to the required specifications. When collecting samples from borings, the following procedure was used:

1. After the drill pipe had been decontaminated, the drill pipe was advanced to the depth at which a sample was to be collected. During this period in between sampling events, the materials encountered during drilling were recorded on a soil boring log.

2. A decontaminated California modified split-spoon sampler equipped with four 6-inch brass sleeves was connected to the appropriate length drill rod and lowered into the borehole through the orifice of the center pipe.

3. A falling hammer was connected to the drill rod, and driven into the undisturbed soil for a depth of 24 inches. The number of blow counts required to drive the sampler for each 6-inch interval was recorded on the soil boring log.

RD/R91/040 14

4. After the falling hammer, drill rod, and the split-spoon sampler had been removed from within the inner orifice of the drill pipe, the hammer was lowered back onto the drill pipe and drilling continued to the next sampling depth.

Chromium Borings

When collecting soil samples for chromium analysis, the following procedure was used:

1. After the sampler had been driven for a depth of 24 inches at a particular 5-foot sampling depth and removed from the borehole, the sampler was disassembled to expose the brass sleeves.

2. The first two 6-inch sleeves were not shipped as capped sleeves, but had their contents extracted with a decontaminated stainless steel spatula, and placed in an appropriately labeled 8-ounce sample jar. This jar contained the soil for the chromium analyses.

3. The excess soil remaining in the second sleeve with the majority of the contents of the third sleeve, was placed in a 16-ounce jar and appro­priately labeled as an archive sample for physical and chemical soil property tests.

4. That portion of the third sleeve which was not placed in the 16-ounce jar was used for completing the boring log.

5. The contents of the fourth 6-inch sleeve was dis­posed of with the cuttings that were generated during the drilling of the borehole.

VOC Borings

In addition to the soil samples collected from soil borings for chromium analyses, soil samples for VOC's were also collected from soil borings. During this sampling effort, a conscious effort was made to avoid the loss of VOC's during sample collection. The method that was used proceeded in such a manner that the soil samples were exposed to the ambient air for only a very brief time period from the point of sample collection to the completion of the sample analysis. The collection of soil samples for VOC analysis proceeded in the following manner:

1. Since a methanol extraction was completed in the field for samples collected for VOC analysis, the

RD/R91/040 15

125-milliliter headspace jars used for sample con­tainers were filled with 25 milliliters of methyl alcohol prior to initiating the day's fieldwork. Prior to sampling, the headspace jars that were expected to be used during that day's work were labeled according to their anticipated sample identification number, date, and initials of the sample team members.

2. Prior to driving the decontaminated California modified split-spoon samplers into the soil at each specified sampling depths, the samplers had been stored in a cooler filled with "Blue-Ice" in sealable plastic bags. This was done to negate the effects of friction generating heat during the driving of the sampler. The drilling subcon­tractor supplied two samplers that were recycled during the drilling operation. This allowed the samplers to remain in a cold environment for approximately 20 minutes in between decontami­nation and use.

3. After the sampler had been driven to collect a sample for one of the specified depths, the sampling team moved rapidly when disassembling the sampler to expose the brass sleeves and collect soil samples. The first 6-inch sleeve contained the soil that was extracted from the sleeve with a stainless steel spatula into the tared headspace jar that was prepared with methyl alcohol.

4. Approximately 10 grams of field-moist soil was placed into each prepared headspace jar that had been appropriately labeled for VOC analysis and tared on a portable electronic balance. After the soil was placed in the jar, the lid was replaced, and the weight of the field-moist soil was recorded on the appropriate line of the chain-of-custody form and in the field notebook.

5. After the sample had been weighed into the jar, the lid tightened down, and the label completed with the necessary information, the labels were covered with clear plastic tape; the lids were sealed with black electrical tape; and the jars were custody-sealed, prepared for shipment, and placed in a cooler containing frozen "Blue-Ice" packages in sealable plastic bags.

6. That portion of the first sleeve which was not used in the collection of samples for VOC analysis was removed from the sleeve along with the con­tents of the second and the majority of the third

RD/R91/040 16

sleeve's contents into a 16-ounce jar that had been labeled as an archive sample for future physical and chemical soil property tests.

7. Approximately a 2-inch slice from the third sleeve's core sample was used in completing the borehole log.

8. The contents of the fourth 6-inch sleeve was dis­posed of with the cuttings generated during the drilling of the borehole.

DEVIATIONS FROM THE SOIL SAMPLING PLAN

During the course of the field investigation and the com­pletion of the sample analyses, a number of decisions were made to expedite the completion of the work associated with this sampling effort and to minimize the cost of this investigation whenever possible. Any of the deviations from the PGA Soil Sampling Plan (CH2M HILL, 1987) that occurred during this investigation were evaluated prior to their initiation to ensure that they would not influence the qual­ity of the work completed at the site or in the laboratory. For ease of discussion, deviations from the PGA Sampling Plan will be discussed according to field or laboratory adjustments.

FIELD EFFORT CHANGES

Field decisions that were made during the course of the sampling phase of this investigation consisted of changes in drilling methods, deleting or moving sampling locations, and the disposal of cuttings generated during the drilling of borings.

Drilling Method

The soil sampling plan described the use of a continuous flight hollow-stem auger as the type of drilling equipment to be used for the investigation, but the drilling subcon­tractor presented the use of a double-wall percussion air hammer as a more effective means of drilling considering the nature of the site's coarse-grained stratigraphy. The air hammer was initially used to collect samples for chromium analysis from the sampling locations at the former sewage treatment facility and at the sampling locations near the former paint tent. At these sampling locations, the air hammer proved to be a more effective and rapid means of collecting samples. This method also allowed for a more accurate description of the vadose zone stratigraphy.

RD/R91/040 17

I

I I I i i t I

i I I I I I I I I

When the sampling for VOC's was initiated, a Mobile P-80 8-inch hollow-stem auger rig was used, but auger refusal occurred at 27 feet and 30 feet at Boring Locations 0901 and 0910, respectively. Based upon the poor performance of the hollow-stem auger, a decision had to be made that would allow the collection of the samples specified in the Sampling Plan.

Because there was concern over the air harmner potentially volatilizing the VOC's from the soil, both rigs were placed side by side at Location 0901, and duplicate samples were collected to a depth of 30 feet (the point of auger refusal) to see if there would be a difference in the results obtained from the analyses of the samples obtained from either drilling method. This location was selected because it had a corresponding soil gas concentration of 9,517 vig/l TCE, but after the results from the analyses of these duplicate samples were obtained, none of the soil samples collected with either drilling method contained TCE or any other VOC in excess of the 0.1 mg/kg detection limit.

After considerable discussions over the strengths and weaknesses of either drilling method, a decision was made to use the double-wall percussion hammer with a 24-inch California modified split-spoon sampler driven ahead of the drill head to avoid the possibility of volatilizing the potential soil contaminants.

Sampling Locations

Certain sampling locations that were initially intended to be sampled were deleted from the sampling effort as a result of denied access, being deemed unnecessary, or because of circumstances in the field.

One background sampling location, 0130, was not sampled because the landowners denied access. As a result, the overall number of background samples was reduced, making it unnecessary to collect field duplicates at Location 0120 because duplicate samples would already comprise 25 percent of the background samples collected.

The Plan had specified that background soil samples would be collected for VOC analyses and for chromium analyses at depth, but after reviewing preliminary data from samples collected onsite, it was determined that the collection of these samples would be unnecessary. This determination was based on the fact that VOC's had not been detected at suspected contaminant source areas, and that the chromium data from samples collected at depth from suspected source areas did not indicate elevated concentrations of chromium.

RD/R91/040 18

! •

The only onsite location that was not sampled was Location 0605. This location was not sampled because an active sewerline was damaged during the excavation of this backhoe test pit, and structures encountered during the excavation of this pit adequately indicated that this location was situated outside of the former sludge bed.

Due to the physical size of the drilling equipment used, a number of sampling locations were adjusted to accommodate the drill rig. The only locations where the relocation of a sampling site was particularly significant were at Locations 0917 and 0804. The location of 0917's corresponding soil gas probe placement was very close to the primary taxiway for much of the airport's aircraft traffic, so the boring location had to be moved. This move resulted in this boring being placed where the earlier soil gas sampling survey had detected TCE at 2.75 yg/l. Location 0804 was moved just to the west of the former airport drain ditch because the split-spoon sampler hit an obstruction at 5 feet that would not allow a sample to be collected, and the airport opera­tions manager requested that the drill rig be moved to the location shown on Figure 8 after the presence of the obstruction was brought to his attention.

Storage of Drill Cuttings

The soil sampling plan had specified that the cuttings gen­erated during drilling operations would be stored in drums prior to disposal according to each boring location, but based on the lack of available space for drum storage, 10-yard roll-off boxes were used. This was found to be a more efficient means of storage. Prior to disposal, com­posite samples of the cuttings will be collected to assess the potential degree of remaining contamination. If the results of these analyses indicate that the contaminants have volatilized, the cuttings will be disposed of onsite; but if the cuttings remain to be contaminated to the degree that they cannot be disposed of onsite, an appropriate waste disposal alternative will be selected.

LABORATORY ANALYTICAL PROCEDURE CHANGES

During the course of the laboratory's involvement in this investigation, there were a number of changes in terms of analytical requests that the laboratory was instructed to make to reduce the analytical time and cost for particular portions of the investigation. The changes that deviated from the sampling plan were focused on the staging of the analyses conducted on the soil samples collected for pesti­cides near the hangar apron area; in reducing the number of samples requiring the water soluble chromium elution tests; and adding the EP Toxicity test for chromium to the group of analytical methods comprising the chromium analytical suite.

RD/R91/040 19

Pesticide Analyses

The analysis of the soil samples collected from the area near the hangar apron was staged in an effort to reduce analytical time and cost. Initially, the staging of the analyses was to proceed with the results from the complete analysis of the first two sampling depths being reviewed to determine whether the remaining two deeper sampling depths warranted being analyzed. But, due to the number of samples to be analyzed and the concern of exceeding the analytical holding times of the samples, all of the samples collected were extracted to meet the analytical holding times and the first two sampling depths were analyzed. After these data were reviewed, it was determined that the analysis of the sampling depths was unnecessary, since there was a marked decrease in pesticide concentrations at the 4- to 8-inch sampling depth, and of the three locations where pesticides were detected none approached the ADEQ soil action limits for 4-DDE' or 4-DDT'.

Soluble Chromium Elution Tests

The sampling plan specified that all of the samples col­lected from a given location would be analyzed for the chromium elution test if any sample contained total chromium in excess of 500 mg/kg. The only samples analyzed from the field investigation that met the total chromium criterion were collected from the former GAC sludge drying beds. All of the samples associated with a sample that exceeded the total chromium criterion would have been analyzed, but the review of the preliminary data revealed an abrupt decrease in chromium concentration with depth rather than gradual attenuation of concentration with depth. It was decided to analyze only the samples that exceeded 500 mg/kg of total chromium for the chromium elution test.

Chromium EP Toxicity Test

The chromium EP Toxicity test was added to the list of analytical parameters after it was learned from the ADEQ that this type of test is required to determine if a reme­dial action is necessary. These tests are currently being completed on soil samples that contain total chromium in excess of 500 mg/kg. The tests will be discussed in the final soils investigation technical memorandum.

RESULTS

The results obtained from the analysis of the background soil samples, and the onsite soil samples analyzed for VOC's, pesticides, and chromium will be discussed according to the area sampled and the type of contaminant being investigated.

RD/R91/040 20

BACKGROUND SITES

Background soil samples were collected from various loca­tions within the PGA Study Area where the Laveen, Glenbar, and Gilman soils were found at areas zoned for agricultural, residential, and industrial use. This matrix was developed to assess if the soils at the airport or GAC were signifi­cantly contaminated to a greater degree than the genetically similar offsite soils, and if the site's soils were contami­nated to a significantly greater degree than other land use areas (Figure 9).

The results obtained from the analysis of samples collected for chromium, metals, and pesticides are found in Tables 4 through 6, respectively.

Pesticides

As was expected, the results of the pesticides analyses from agricultural sites contain 4-DDE' and 4-DDT' at greater con­centrations than the other background sampling locations. At Location 0110, 4-DDE' was detected at 1.13 mg/kg and 1.47 mg/kg at depths of 4 to 8 inches and 8 to 15 inches, respectively. Both concentration values are in excess of the ADEQ action limits for 4-DDE'. Of the two agricultural sites sampled. Locations 0110 and 0120, there is a defi­nite greater proportion of 4-DDE' to 4-DDT'. It appears that a degradation process of some kind has possibly brought about the transformation of 4-DDT' to form 4-DDE'.

Of the remaining background sites sampled for pesticides. Location 0320, a zoned residential site, and Location 0210, a zoned industrial site, have somewhat anomalous pesticide concentrations. Location 0210's pesticide concentrations can possibly be attributed to the fact that this location is adjacent to an agricultural area, but unlike the other agricultural sites, the concentration of 4-DDT' is greater than 4-DDE'. Location 0320 has the highest concentration of pesticides from any of the zoned residential sites, and the concentration of 4-DDE' does not decline with depth like the majority of the other background sampling locations.

Chromium and Metals

Of the background locations where samples were collected for total chromium and the metals analytical suite, all of the chromium concentrations and other metals concentrations are consistent for all of the sampling locations.

RD/R91/040 21

Table 4 PESTICIDE CONCENTRATIONS FROM BACKGROUND SAMPLING LOCATIONS

(mg/kg)

to

Sampling

Depth

(inches)

0-4 4-8 8-15 15-30

Sampling

Depth

(inches)

0-4 4-8 8-15 15-30

Sampling

Depth

(inches)

0-4 4-8 8-15

15-30

DDE

0.93 1.13 1.47 0.05

DDE

0.18 0.02 0.02

ND

DDE

0.8 ND 0.02

ND

0110

0220

0311

DDT

0.28 0.50 0.99

ND

DDT

0.01 ND ND ND

DDT

0.01 ND 0.01 ND

DDE

0.40 0.03 0.35 0.47

DDE

0.02 0.02 0.02

ND

DDE

0.42 0.43 0.61 0.87

0120

0230

0320

Test Pit

DDT

0.02 0.01 0.01 0.02

Test Pit

DDT

ND ND ND ND

Test Pit

DDT

0.05 0.21 0.13 0.09

Location

DDE

0.24 0.18 0.12 0.01

Location

DDE

0.01 ND ND ND

Location

DDE

0210

0310

DDT

0.32 0.40 0.26 0.03

DDT

ND ND ND ND

DDT

DDE

0.16 0.24 0.18 0.01

DDE

ND ND ND ND

DDE

0241

0341

a

DDT

0.07 0.29 0.32

ND

b

DDT

ND ND ND ND

DDT

Fielci duplicates of Test Pit Location 0210.

Field duplicates of Test Pit Location 0310.

Note: All concentrations reported on an oven dry basis.

ND = Not detected at a concentration greater than 0.01 mg/kg.

RD/R15/015-1

Table 5 CHROMIUM CONCENTRATIONS FROM BACKGROUND SAMPLING LOCATIONS

(mg/kg)

Sampling Depth

(inches)

0-4 4-8 8-15

15-30 30-45 45-60 60-90 90-120

Sampling Depth

(inches)

0-4

4-8

8-15

15-30

30-45

45-60

60-90

90-120

0110

15 16 16 14 12 14 16 12

0311

24

20

21

16

19

19

18

19

0120

34 36 34 24 25 22 14 13

0320

21

18

21

20

18

21

18

11

0210

16 14 17 17 13 18 22 30

Test Pit

0241^

14 15 14 14 15 15 21 22

Test Pit

Location

0220

16 16 16 15 16 18 15 13

Location

0230

28 19 29 22 22 23 21 16

0310

27 26 27 20 15 14 21 15

034l'=

27 21 18 16 18 15 16 15

Field duplicates of Test Pit Location 0210.

^Field duplicates of Test Pit Location 0310. Note: All concentrations reported on an oven dry basis.

RD/R15/016-1

Table 6 CONCENTRATIONS OF METALS FROM BACKGROUND SAMPLING LOCATIONS

(mg/kg)

K)

>̂

Sampling Depth (inches)

0-4 4-8 8-15 15-30

Sampling Depth (inches)

0-4 4-8 8-15 15-30

Sampling Depth (inches)

0-4 4-8 8-15

15-30

Sampling Depth (inches)

0-4 4-8 8-15 15-30

Al

8,822 8,401 8,056 8,236

Al

15,497 13,832 16,067 16,817

Al

9,381 7,963 13,147 9,748

Al

8,421 8,379 8,421 8,500

As

8.6 9.5 8.6 8.7

As

6.1 6.0 6.5 6.5

As

9.5 9.2 8.7 10.2

As

7.3 8.1 8.6 11.5

Ba

130 158 158 218

Ba

168 164 169 169

Ba

152 154 176 178

Ba

142 163 165 177

Test

Cd

0.4 0.3 0.6 0.5

Test

Cd

1.2 1.0 1.7 0.6

Test

Cd

0.3 0.4 0.2 0.3

Pit

Pit

Pit

Test Pit :

Cd

0,4 0.4 0.4 0.4

Location 0110

Cu

13 11 11 10

Hg

ND ND ND ND

Location 0120

Cu

24 23 25 23

Hg

ND ND ND ND

Location 0210

Cu

15 14 16 15

Location

Cu

15 14 14 14

Hg

ND ND ND ND

0241^

Hg

ND ND ND ND

Mn

205 180 169 160

Mn

419 348 371 463

Mn

314 287 290 283

Mn

263 255 289 250

Ni

12 12 12 10

Ni

19 17 20 20

Ni

15 14 13 15

Ni

14 13 12 14

Pb

9.5 9.3 8.0 5.7

Pb

11.5 8.7 11.2 10.4

Pb

8.2 6.6 6.8 5.5

Pb

9.1 7.3 7.3 7.1

Zn

32 30 33 25

Zn

63 60 81 54

Zn

37 34 36 34

Zn

35 33 33 31

RD/R15/018-1

Table 6 (continued)

N>

Sampling Depth (inches)

0-4 4-8 8-15 15-30

Sampling Depth (inches)

0-4 4-8 8-15 15-30

Sampling Depth (inches)

0-4 4-8 8-15 15-30

Sampling Depth (inches)

0-4 4-8 8-15 15-30

Al

9,375 10,192 11,315 9,420

Al

8,558 9,130 15,328 12,685

Al

16,083 18,311 19,268 12,513

Al

15,470 11,790 12,283 10,063

As

10.1 9.9 9.8 8.1

As

16.1 12.1 9.4 9.6

As

8.5 13.2 12.9 7.5

As

8.7 13.1 14.1 8.6

Ba

151 172 173 163

Ba

151 121 156 116

Ba

142 164 172 147

Ba

155 153 152 147

Test

Cd

0.4 ND 0.4 0.4

Test

Cd

0.3 0.2 0.4 0.4

Test

Cd

0.4 0,5 0.3 0.2

Pit Location 0220

Cu

20 19 20 19

ND ND ND ND

Pit Location 0230 " •

Cu

18 18 27 23

Hg

ND ND ND ND

Pit Location 0310

Cu

30 36 33 20

Test Pit Location

Cd

0.3 0.3 0.4 0.3

Cu

28 29 29 20

Hg

ND ND ND ND

0341^

Hg

0.25 0.13 0.30 0.36

Mn

383 454 428 438

Mn

323 313 626 507

Mn

449 592 527 379

Mn

464 524 435 389

Ni

19 19 20 18

Ni

18 18 26 23

Ni

32 36 36 25

Ni

30 31 32 24

Pb

11.1 6.6 6.9 6.2

Pb

9.5 6.9 9.6 8.9

Pb

24.1 15.4 10.8 8.6

Pb

29.8 19.7 14.1 11.6

Zn

43 40 42 41

Zn

39 35 62 51

Zn

72 61 54 41

Zn

66 52 45 37

RD/R15/018-2

Table 6 (continued)

M (T\

Sampling Depth (inches)

0-4 4-8 8-15 15-30

Sampling Depth (inches)

0-4 4-8 8-15 15-30

Al

14,442 14,485 14,454 10,086

Al

13,679 11,452 11,423 11,895

As

8.6 10.1 9.9 7.8

As

10.4 9.2 8.4 8.4

Ba

142 150 171 194

Ba

197 174 166 158

Test

Cd

0.3 0.5 0.5 0.5

Test

Cd

0.6 0.6 0.2 0.2

Pit Locat

Cu

24 25 25 19

ion 0311

Hg

ND ND ND ND

Pit Location 0320

Cu

27 20 24 24

Hg

ND ND 0.12

ND

Mn

416 472 471 399

Mn

487 368 467 516

Ni

25 27 29 23

Ni

27 25 28 27

Pb

15.3 10.7 10.7 8.2

Pb

17.6 9.0 9.8

11.6

Zn

59 49 50 39

Zn

54 47 51 52

Field duplicates of Test Pit Location 0210.

Field duplicates of Test Pit Location 0310.

Note: All concentrations reported on an oven dry basis.

ND = Not detected at a concentration greater than those found in Table 2.

RD/R15/018

RD/R15/018-3

The background aluminum concentrations are all greater than the ADEQ limits, but this action limit is prefaced by being subject to the determination of natural soil levels. When compared to onsite aluminum data, these data should reveal that the site's aluminum levels are not substantially greater than naturally occurring offsite conditions.

VOC BORINGS

Soil samples were collected for VOC analyses from borings completed at the locations where the previous soil gas survey detected TCE at a concentration equal to or greater than 10 yg/l, adjacent to the hangar apron and former air­craft washracks, and along the course of the former airport drain ditch near the outfall of GAC Drain 001 (Figures 3 and 8).

With the exception of methylene chloride, TCE was the only compound of all the VOC's being investigated that was consistently quantified above the 0.1 mg/kg detection limit. Methylene chloride was detected in nearly all of the samples and blanks analyzed, and its presence has been attributed to instrument contamination.

The six boring locations where TCE was quantified above the ADEQ suggested soil action limit of 260 yg/l to 320 yg/l are listed in Table 4. The highest concentrations of TCE detected were 2,270 yg/l at Boring 0902 at a depth of 30.5 to 31.5 feet, and 2,510 yg/l at Boring 0903 at a depth of 45.5 to 46.5 feet. With the exception of Boring 0909 and 0913, all of the borings with samples containing TCE above the ADEQ soil action limits are all close to existing sewerlines that service the former GAC facility.

In addition to the borings containing TCE in excess of the ADEQ soil action limits, TCE was detected in samples col­lected from Borings 0914 and 0803. At Boring Location 0803, located in the airport drain ditch near the outfall of Drain 001, TCE was detected at a concentration of 220 yg/l at a depth of 50.5 to 51.5 feet. At Location 0914, TCE was detected at 120 yg/l at 35.5 to 36.5 feet (Table 7). Boring 0913 was the only boring containing any of the other constituents from the VOC analytical suite. At this loca­tion, 1,1,1-TCA was detected at a concentration of 120 yg/l.

PESTICIDES

Soil samples for pesticide analyses were collected from backhoe test pits near the hangar apron area, as composite samples adjacent to the airport drain ditch to the west of the runway, and also as composites from the airport fill disposal area at the extreme southwestern end of the airport property (Figures 3, 4, and 5).

RD/R91/040 27

Table 7 TCE CONCENTRATIONS IN SOIL

(yg/kg)

Samp; (f

5.5 10.5 15.5 20.5 25.5 30.5 35.5 40.5 45.5 50.5 55.5 60.5 65.5

.e Depth "eet)

_

-------

^

--

6.5 11.5 16.5 21.5 26.5 31.5 36.5 41.5 46.5 51.5 56.5 61.5 66.5

0902

ND ND 360 850 120

2,270 440 ND ND ND NS Ns""

0903

ND ND ND 280 520 740 250 ND

2,510 870 460 790 ND'̂

Boring Location 0908

ND

ND ND ND 240 530 ND 220 ND ND^

100^ ND*^

0909

ND

ND ND ND ND ND ND ND ND 300*^

0910

ND

ND ND 110 330 ND ND ND 450

= 110 ND NS'^

0913

ND

ND ND 260 ND 120 ND ND ND ND

ND Ns""

0914

ND ND ND ND ND ND ND ND ND 120 ND ND ND^

0803

ND ND ND ND ND ND ND ND ND 220^

All data reported on an oven dry basis unless otherwise noted.

Data reported on a wet weight basis. Q

Last sampling depth of the boring. ND = Not detected at a concentration greater than 100 yg/kg. NS = No sample due to limited recovery.

As mentioned earlier, the analysis of the samples collected from backhoe test pits near the hangar apron area were analyzed in a stepwise fashion to reduce the overall analytical costs and to expedite the completion of the analytical work. After all of the samples had been extracted, the 0 to 4 inch and 4 to 8 inch samples were analyzed for 4-DDE' and 4-DDT' (Table 8). The review of these preliminary data resulted in none of the remaining samples being analyzed since the results of these analyses did not approach the ADEQ soil action limits of 1.0 mg/kg for 4-DDE' and 4-DDT'. This decision was also supported by the marked decrease in pesticide concentrations at the 4- to 8-inch sampling depth.

The composite samples collected from the sediments adjacent to the airport drain ditch and from the airport fill dis­posal area (Figures 3 and 5) contained both 4-DDT' and 4-DDE' at consistently higher concentrations than the samples collected near the hangar apron area. One sample, 0503, contained 4-DDE' at a concentration of 1.18 mg/kg.

RD/R91/040 28

Table 8 PESTICIDE CONCENTRATIONS FROM THE HANGAR APRON AREA

,a (mg/kg)

Sample Test Pit Location

NJ yo

Depth

(inches)

0 to 4

4 to 8

b 8 to 15

15 to 30̂ '̂ =

Sample

Depth

(inches)

0 to 4

4 to 8

8 to 15^

15 to 30̂ '̂ =

0401 0402 0403

DDE

0.01

ND

DDE

0.01

ND

ND

DDT DDE DDT DDE

0.02 ND 0.01 ND

ND ND ND ND

0410 0411

DDT DDE DDT

0.02 0.03 0.05

ND ND ND

ND

DDT

0.07

ND

0404

DDE

ND

ND

0412

DDE

0.03

ND

DDT

0.02

0.01

DDT

0.01

ND

Test

0405

DDE

ND

ND

ND

DDT

ND

ND

ND

Pit Location

0413

DDE

ND

ND

DDT

ND

ND

DDE

0.02

ND

0406

DDE

ND

ND

0414

DDT

0407

DDT DDE

ND 0.01

ND ND

DDT

0.02

ND

0415

DDE

0.02 0.17

ND 0.03

ND

DDT

0.33

0.22

ND

0408

DDE DDT

0.04 0.07

ND ND

0416

DDE DDT

0.02 0.01

ND 0.01

0409^

DDE DDT

0.04 0.07

ND ND

0417^

DDE DDT

ND ND

ND 0.02

ND ND

All (3ata reported on an oven dry basis. b Samples extracted but not analyzed.

c Any data appearing at this depth is a result of every tenth sample received by the laboratory being a

replicate spike sample.

d Field duplicate samples of Location 0408.

e F ie ld dup l i ca t e samples of Location 0416.

ND = Not detected a t a concentrat ion g rea t e r than 0.01 mg/kg.

R D / R 8 8 / 0 2 7 - 1

which is in excess of the ADEQ soil action limit (Table 9). At either location where composite samples were collected, the concentrations of 4- DDE' were consistently greater than the concentrations of 4-DDT'. This difference can possibly be attributed to the fact that 4-DDE' is a degradation product of 4-DDT', and that these sediments are the result of the runoff and subsequent erosion of agricultural lands that received applications of DDT many years ago to suppress infestations of pink bole worm in cotton. These data indicate that both pesticides are long-lived in soils, and that some degradation mechanism possibly has acted on 4-DDT' to result in comparatively greater concentrations of 4-DDE'.

Table 9 PESTICIDE CONCENTRATIONS IN SEDIMENTS DERIVED FROM THE AIRPORT DRAIN DITCH

(mg/kg)

Sample Depth (inches)

0501 DDE DDT

Test Pit Location 0502 0503 0504

DDE DDT DDE DDT DDE DDT 0505^

DDE DDT

0-60 0.49̂ 0.41̂ 0.79 0.45 1.18 0.78 0.49 0.22 0.46 0.27

Sample Depth (inches)

0506 DDE DDT

Test Pit Location 0507 0508 0509

DDE DDT DDE DDT DDE DDT 0510^

DDE DDT

0-60 0.57 0.22 0.48 0.09 0.86 0.18 0.45 0.17 0.49 0.20

Results are on a dry weight basis unless otherwise noted.

Results are on a wet weight basis.

Field duplicates of Location 0504.

Field duplicates of Location 0509.

METALS

Additional samples were collected from the former GAC sludge drying beds to attain additional metals data for the study

RD/R91/040 30

area's Preliminary Public Health Endangerment Assessment and to assess the potential of surface soil contamination by other metals.

Of the samples collected from Sludge Bed No. 1, the larger western bed (Figure 6), the surface 0- to 4-inch samples collected from Locations 0604 and 0606 contained cadmium in excess of the ADEQ soil action limit of 10 mg/kg (Table 10). Also, the sample collected from the 4- to 8-inch depth at Location 0602 contained cadmium at a concentration of 23.9 mg/kg. The only other sample with elevated concen­trations of any of the other metals was derived from Location 0606, where copper was detected at a concentration of 303 mg/kg. This concentration just exceeds the ADEQ action limit for copper of 300 mg/kg.

Elevated cacJmium concentrations were also detected in the samples collected from Sludge Bed No. 2 at Locations 0701 and 0705. Cadmium in excess of ADEQ's action limit was detected in all of the samples from 0701 that were analyzed for metals, with the greatest concentration of 122 mg/kg occurring at a depth of 8 to 15 inches. At Location 0705, cadmium was detected at 15.3 mg/kg.

The remaining samples collected from Sludge Bed No. 2 that were analyzed for these additional metals did not contain elevated concentrations of the other metals investigated.

CHROMIUM

Soil samples were collected for chromium analyses at the following locations: near the hangar apron area and the former aircraft washracks, the former GAC sludge drying beds, at the former location of the airport's sewage treatment facility, and along the course of the airport drain ditch near the outfall of Drain 001 (Figures 3, 6, 7, and 8). Of the locations sampled for chromium analyses, one of the sludge drying beds detected chromium concentrations in excess of the ADEQ soil action limit of 1,500 mg/kg of total chromium.

Soil samples were collected from the former GAC sludge drying beds from backhoe test pits excavated to a depth about 10 feet, and samples were collected at the following depths: 0 to 4 inches, 4 to 8 inches, 8 to 15 inches, 15 to 30 inches, 30 to 45 inches, 45 to 60 inches, 60 to 90 inches, and 90 to 120 inches.

RD/R91/040 31

Table 10 METAL CONCENTRATIONS FROM THE GAC SLUDGE DRYING BEDS

(mgAg)

NJ

Sampling Depth (inches)

0-4 4-8 8-15

Sampling Depth (inches)

0-4 4-8 8-15

Sampling Depth (inches)

0-4 4-8 8-15

Sampling Depth (inches)

0-4 4-8 8-15

Al

10,467 7,121 9,586

Al

9,939 10,995 10,851

AI

10,243 10,082 10,093

Al

9,072 10,747 9,958

As

9.9 7.7 8.7

As

8.7 9.0 8.2

As

10.1 7.6 6.9

As

8.2 6.6 11.4

Ba

132 135 179

Ba

142 168 138

Ba

162 143 145

Ba

161 81 156

Test

Cd

6.5 23.9 3.0

Test

Cd

3.5 1.6 1.3

Test

Cd

20.3 2.2 1.4

Test

Cd

11.1 1,1 1.1

Pit

Pit

Pit

Pit

Locat

Cu

24 20 26

ion 0602

Hg

0.11 0.11

ND

Location 0603

Cu

19 18 17

Hg

ND ND ND

Location 0604

Cu

22 23 23

Hg

ND 0.11 0.11

Location 0606

Cu

303 19 18

Hg

0.11 0.11

ND

Mn

335 249 268

Mn

294 283 266

Mn

274 296 331

Mn

283 358 312

Ni

17 26 28

Ni

15 15 13

Ni

17 15 15

Ni

19 16 15

Pb

20.3 18.7 7.0

Pb

8.8 8.7 7.3

Pb

25.4 9.7 6.8

Pb

41.4 5.6 5.6

Zn

61 44 35

Zn

43 40 35

Zn

85 40 39

Zn

242 39 36

RD/R15/017-1

Table 10 (continued)

CJJ

OJ

Sampling Depth (inches)

0-4 4-8 8-15

Sampling Depth (inches)

0-4 4-8 8-15

sampling Depth (inches)

0-4 4-8 8-15

Sampling Depth (inches)

0-4 4-8 8-15

Al

10,303 9,240 8,635

Al

10,275 27,778 6,107

Al

16,410 10,681 12,940

Al

12,012 9,947 9,502

As

11.1 8.2 8.5

As

13.2 9.3 11.5

As

12.3 9.0 11.2

As

11.3 11.6 8.7

Ba

152 156 160

Ba

193 189 232

Ba

195 199 238

Ba

226 221 166

Test

Cd

4.8 1.4 1.4

Test

Cd

11.2 11.5 112

Test

Cd

19.5 15.7 63.6

Test

Cd

2.9 2.2 2.9

Pit Location

Cu

19 17 1 15

Pit Location

Cu

39 46 301

Pit Location

Cu

47 49 193

Pit Location

Cu

32 24 32

0608

Hg

0.84 ND 0.12

0701

Hg

0.20 0.15 1.48

0702^

Hg

0.11 0.12 1.43

0703

Hg

0.11 0.12 0.17

Mn

263 291 203

Mn

356 409 359

Mn

338 387 341

Mn

370 347 270

Ni

15 14 13

Ni

22 22 49

Ni

17 20 37

Ni

18 18 16

Pb

8.3 7.0 6.3

Pb

4.6 34.6 92.7

Pb

23.5 34.6 68.1

Pb

50,3 30.5 17.6

Zn

48 34 30

Zn

102 168 359

Zn

113 136 250

Zn

94 54 114

RD/R15/017-2

Table 10 (continued)

Sampling Depth (inches)

0-4 4-8 8-15

Al

8,049 8,763 7,812

As

11.2 7.5 7.7

Ba

184 136 159

Test

Cd

15.3 1.3 1.7

Pit

-

Location

Cu

45 19 20

0705

Hg

0.21 0.12 0.12

Mn

337 356 370

Ni

17 14 15

Pb

24,5 5.9 32.8

Zn

94 37

116

Field duplicates of Location 0701. Note: All concentrations reported on an oven dry basis, ND = Not detected at a concentration greater than 0.11 mg/kg.

OJ RD/R15/017

RD/R15/017-3

Sludge Bed No. 1, the larger bed to the west, did not con­tain any samples exceeding the ADEQ soil action limits for total chromium. A sample was collected from one location at a depth of 4 to 8 inches that contained a total chromium concentration of 525 mg/kg as shown on Table 11. With the exception of the surface 0- to 4-inch samples, and the samples collected from 4 inches to 15 inches from Loca­tion 0601, none of the remaining samples appeared to contain total chromium concentrations in excess of preliminary back­ground data.

Table 11 CHROMIUM CONCENTRATIONS FROM GAC

SLUDGE DRYING BED NO. 1 (mgAg)

Sample

Depth

(inches)

0 - 4 4 - 8 8 - 1 5 15 - 30 30 - 45 45 - 60 60 - 90 90 - 120

0601

184 525 76 17 16 20 30 46

0602^

75 519 167 16 17 18 55 44

Test

0603

56 24 20 19 17 23 17 28

Pit Location

0604

152 17 17 16 16 19 20 21

0606

222 18 16 19 17 19 18 15

0607

18 15 15 18 15 22 22 20

0608

41 16 16 14 15 31 30 40

All data reported on an oven dried basis.

Field duplicates of Location 0601.

Soil samples collected from Sludge Bed No. 2, the smaller bed to the east, contained concentrations of total chromium in excess of twenty times the ADEQ soil action limit. As shown on Table 12, with the exception of Locations 0705 and 0706, the greatest concentrations of total chromium (32,243 mg/kg) occurs at a depth from 8 inches to 45 inches.

The samples from either sludge bed that contained greater than 500 mg/kg of total chromium are currently being analyzed with water soluble chromium elution and EP Toxicity tests to evaluate the solubility of the chromium present in the soils at the former GAC facility.

RD/R91/040 35

Table 12 CHROMIUM CONCENTRATIONS FROM GAC SLUDGE DRYING BED NUMBER 2

(mgAg)

OJ CTi

Sample Depth

(inches)

0 -

4 -

8 -

15 -

30 -

45 -

60 -

90 -

4

8

15

30

45

60

90

120

0701

478

461

23,290

26,072

3,194

44

62

46

0702^

615

513

13,847

32,243

7,022

44

74

60

0703

184

83

134

3,642

27,843

38

36

30

Test Pit Location

0704

133

515

2,861

7,134

30

45

32

49

0705

398

17

16

56

17

17

16

17

0706

131

25

22

18

15

17

20

23

0707

2,184

62

1,311

8,159

29,461

63

55

39

All data reported on an oven dried basis.

Field duplicates of Location 0701,

RD/R88/027-2

Of the remaining locations where soil samples were collected for total chromium analyses, none contained elevated total chromium concentrations (Tables 13, 14, 15, and 16).

FUTURE ANALYSES

Currently, analyses on those samples that contained contami­nants in excess of the threshold concentration values for additional soil property tests are being completed. Once the results from these analyses are complete, the data will be used for investigating the possible soil/contaminant relationships that may exist at the site. The data will also be used to more accurately define the site's stratigraphy.

RD/R91/040 37

Table 13 CHROMIUM CONCENTRATIONS FROM FORMER

Sample Depth

(feet)

5.5 - 6.5 10.5 - 11.5 15,5 - 16,5 20.5 - 21.5 25.5 - 26.5 30.5 - 31.5

SEWAGE

1001

30 20 21 83 NS NS

TREATMENT (mg/kg)

1002^

27 19 76 32 NS NS

d FACILITY

Boring Location 1003

19 22 43 40 NS NS

1004

16 15 20 31 7.5

NS

1005

20 16 16 70 9.1 11

All data reported on an oven dry basis.

Field duplicates of Location 1003.

NS = No sample due to limited recovery.

Table 14 CHROMIUM CONCENTRATIONS ALONG THE COURSE OF THE AIRPORT

DRAIN DITCH NEAR THE OUTFALL OF DRAIN 001 (mg/kg)

Sample

(fei

5.5 -10.5 -15.5 -20.5 -25.5 -30.5 -

35.5 -40.5 -

45.5 -50.5 -55.5 -

Depth

Bt)

6.5 11.5 16.5 21.5 26.5 31.5

36.5 41.5 46.5 51.5

56.5

0801

54 41 82 24 28 7.0 9.8 8.7 6.4 11 NS

Boring

0802^

54 45 66 14 18 6.1 19 5.4 6.5 6.1

NS

Location

0803

25.8 43.6

17.0 28.7 12.8 9.7 6.1 4.4 5.8 8.3

NS

0804

43 24 32 19 17 10 78 11 48 13 NS

0910

17.8 5.7 8.4

23.1 13.0 10.1 7.2 6.7 7.6

10.9 11.6

All data reported on an oven dry basis.

Field duplicates of Location 0801.

NS = No sample due to limited recovery.

RD/R91/040 38

Table 15 CHROMIUM CONCENTRATIONS FROM THE FORMER PAINT TENT AREA

(mg/kg)

Sample

(fe

5.5 -10.5 -15,5 -20.5 -25.5 -30.5 -35.5 -40.5 -

Depth

2t)

6.5 11,5 16.5 21.5 26.5 31.5 " 36.5 41.5

1101

16 37 59 34 15 21 17 13

Boring

1102

17 64 64 54 21 21 23 34

Location

1103

30 29 22 13 27 32 30 NS

1104^^

31 30 24 12 28 27 13 NS

All data reported on an oven dry basis,

Field duplicates of Location 1103. NS = No sample due to limited recovery.

Table 16 CHROMIUM CONCENTRATIONS FROM THE HANGAR APRON AREA

(mg/kg)

Sample (fei

5.5 -10.5 -15.5 -20.5 -25.5 -30.5 -35.5 -40.5 -45.5 -50.5 -55.5 -60.5 -

Depth 5t)

6.5 11.5 16.5 21.5 26.5 31.5 36.5 41.5 46.5 51.5 56.5 61.5

0919

15 20 50 32 19 12 19 12 16 60 29 15

Boring 0920

23 38 48 26 31 9.0

15 29 10 9.9

12 NS

Location 0921

17 9.0

12 NS 20 24 6.2 9.4

NS 11 NS NS

0922

7.9 12 9.7

28 13 7.3 7.9 7.3 9.8

27 NS NS

All data reported on an oven dry basis unless otherwise noted. NS = No sample due to limited recovery.

RD/R91/040 39