PUBLIC HEALTH ASSESSMENT
MCCHORD AIR FORCE BASE
PIERCE COUNTY, TACOMA, WASHINGTON
Figures
Figure 1. McChord AFB and Vicinity
Figure 2. Hazardous Waste Disposal Sites
at McChord AFB
Figure 3. Environmental Contamination
Study Areas at McChord AFB
Figure 4. On-Base Housing and
Off-Base Residential Areas
Figure 5. On-Base Drinking Water Wells
Figure 6. Area A
Estimated Extent of
Floating Hydrocarbons
Figure 7. WTA - Areas of
Suspected Contamination
Figure 8. WTA - Approximate Extent
of Floating Fuel and Locations of
Monitoring Wells
Figure 9. WTA - Surface Water and
Sediment Sampling Locations
Figure 10. Area D/ALGT -
TCE Contamination Plume
and Waste Sites
Background and Information on
On-base Contamination
(65 Sites by Area)
Tables in Appendix B
Area A
Sites 1, 2, 34, and 46
Background
Study Area A is currently used for bulk jet fuel (JP-4) storage. That storage area, which is on the north-central part of the base, is bounded by the base property line and McChord Avenue to the north. It is bounded on the east by the Burlington Northern Railroad tracks. Major activities in Area A are currently limited to liquid fuels bulk storage and liquid fuels distribution using truck filling stands immediately east of the railroad tracks. Figure 3 in Appendix A shows the site locations; Table B-1 lists information about the types of wastes disposed or spilled at Area A.
Table B-1. Waste History - Area A
| Site | Site Description | Wastes | Disposal/ Spill Dates |
| 1 | Burial pit | Boiler Ash, industrial waste | 1946-1956? |
| 2 | Milburn Pond landfill | Boiler Ash, industrial, domestic, construction, demolition | 1957-1976 |
| 34 | Tank farm area | Fuel tank sludge, fuel (JP-4 and leaded fuel) disposal; fuel spills | 1956-? |
| 46 | Fuel (JP-4) spill | 50,000-gallon JP-4 fuel spill; no remediation | late 1960s |
Site 1, a burial pit, and Site 2, Milburn Pond landfill, may have received large quantities of industrial wastes. The fuel storage in Area A (Site 34) consists of four aboveground JP-4 storage tanks with capacities ranging from 210,000 to 840,000 gallons. A 20,000- to 30,000-gallon dry pit is outside the northwestern corner of the tank farm. According to the Phase I investigation, this pit has probably received waste fuel (Hazardous Waste Remedial Actions Program [HAZWRAP] 1989). Tank sludges have also been dumped on unlined ground outside the tank farm fence. The practice of draining and drying aircraft fuel filters on a gravel pad west of and outside of the tank farm was stopped in 1982. An oil/water separator and dry well discharge system in the northwestern corner of the storage facility have received discharge from storm drainage within the bermed area of the tank farm. Water with an oily sheen was noted in the dry well during one investigation (Dames and Moore 1987). Waste fuels were not always separated from the storm drainage before discharge into the dry well; those fuels may have infiltrated into the soils (HAZWRAP 1989; CH2M-Hill 1982). The tank farm was upgraded in 1984; an impermeable liner was installed on all berms and on the floors of the containment cells.
Fuel spills have taken place at the tank farm, including a spill of 15,000 gallons of aviation gas (AVGAS) in 1973 and a reported spill of 50,000 gallons of JP-4 fuel in the railroad yard east of the tank farm in the late 1960s. Fuel was also spilled at the railroad yard (Site 46) during the late 1960s; apparently, all of the spilled fuel infiltrated the ground.
Environmental Contamination
Groundwater at Area A was monitored during five different studies. One study (HAZWRAP 1989) also analyzed soil samples for contamination. During site hazard assessment (EBASCO Services Incorporated 1993), surface water and sediment samples within Milburn Pond were sampled.
During an investigation by Dames and Moore in 1987, subsurface conditions at Area A were found to be highly complex and variable, causing concern about the possible movement off base of the fuel contamination floating on the water table.
Groundwater
During the IRP Phase II, Stage 1 investigations, analysis of samples from three newly constructed monitoring wells at Area A found that petroleum hydrocarbons were floating on the water table immediately west of the bulk fuel storage tanks. The main text of this public health assessment contains additional information about the Phase II, Stage I and 2 Studies. ATSDR has excluded the Phase II data for Area A from this public health assessment because more recent environmental data are available from two other studies.
In February 1987, Dames and Moore published "Report on Restoration of Contaminated Area A Fuel-Contaminated Groundwater at McChord AFB." The purposes of that investigation were to collect and analyze data to define alternatives for cleanup of the floating hydrocarbons and to estimate the costs of the cleanup. Five monitoring wells installed during previous investigations and seven wells installed in 1986 were sampled in June 1986 to determine the presence or absence of hydrocarbons floating on the water-table surface. The samples were analyzed for benzene, toluene, and xylene.
HAZWRAP published "Characterization of JP-4 Fuel Spill in Area A" in November 1989. The purpose of that investigation was to assess the nature and extent of fuel contamination at Area A. Four additional monitoring wells were installed at the northern end of Area A. Samples from both previously built and new monitoring wells were analyzed for volatile organic compounds (VOCs), total petroleum hydrocarbons (TPHs), and metals. All groundwater samples for metals analysis were filtered. Figure 6, Appendix A, shows the estimated extent of floating hydrocarbons during the summer of 1988.
Four additional monitoring wells were installed during site hazard assessment in February 1993 at Sites 1 and 2. At Site 1, one well was installed upgradient (depth: 36 feet) and the other downgradient (depth: 44 feet). At Site 2, one well was installed upgradient (depth: 23 feet) and the other downgradient (depth: 27 feet). Groundwater sampling was conducted in March 1993. Samples were analyzed for volatile and semi-volatile organic compounds, pesticides and polychlorinated biphenyls (PCBs), inorganics, and total petroleum hydrocarbon (TPH) compounds. The concentrations of groundwater contaminants exceeding comparison values during the three most recent investigations at Area A are summarized in Table B-2.
Table B-2. Contaminant Concentrations in On-Base Groundwater Monitoring Wells - Area
A
| Groundwater Contaminant | Range of Levels (ppb) |
Date | Reference | Comparison Value | |
| (ppb) | Source | ||||
| Benzene | 20-42 16-54 |
1986 1987-1988 |
Dames and Moore HAZWRAP |
1.2 | CREG |
| 1,1-Dichloroethene | 1-3 | 1993 | EBASCO | 0.06 | CREG |
| cis-1,2-Dichloroethene | 87 | 1993 | EBASCO | 70 | LTHA |
| Tetrachloroethylene | 4-14 | 1993 | EBASCO | 0.7 | CREG |
| Trichloroethylene | BDL-20 17-40 |
1987-1988 1993 |
HAZWRAP EBASCO |
3 | CREG |
| Antimony | BDL-8 | 1987-1988 | HAZWRAP | 4 | RMEG-Child |
| Arsenic | BDL-122 | 1987-1988 | HAZWRAP | 0.02 | CREG |
| Beryllium | 0.39-0.6 | 1993 | EBASCO | 0.008 | CREG |
| Cadmium | BDL-6 | 1987-1988 | HAZWRAP | 2 | EMEG-Child |
| Lead | BDL-240 | 1987-1988 | HAZWRAP | None | EPA-Carcinogen |
BDL: Below detection limit.
Subsurface Soil
Subsurface soil samples were collected at selected intervals from the borings for the new monitoring wells installed during the HAZWRAP investigation. No VOCs were detected in those samples, and the concentrations of metals were less than their respective comparison values, except for arsenic. The concentration for lead at Area A is included in Table B-3 because no comparison values for that metal are currently available. The concentration of lead in the soil at Area A is similar to background concentrations found in other soil from the Western United States (ATSDR 1992).
Table B-3. Range of Contaminant Concentrations in On-base Soil Samples - Area A
| Contaminant | Range of Levels (ppm) |
Depth | Date | Reference | Comparison Value | |
| (ppm) | Source | |||||
| Arsenic | 9.2-14.1 | 5-foot intervals | 1987-1988 | HAZWRAP | 0.4 | CREG |
| Lead | 6.2-7.8 | 5-foot intervals | 1987-1988 | HAZWRAP | None | EPA-Carcinogen |
Surface Water and Sediment
Surface water and sediment samples were collected at two locations within Milburn Pond (EBASCO 1993). Those samples were analyzed for volatile and semi-volatile organic compounds, pesticides and polychlorinated biphenyls (PCBs), inorganics, and total petroleum hydrocarbon (TPH) compounds. Metals were detected at naturally-occurring concentrations. Comparison values are not available for surface water.
Area B
Sites 38, 40, 41, 47, 52, 53, and 55
Background
Area B, which is the northern part of the industrial area at McCAFB, consists of seven liquid waste disposal sites behind and along the aircraft maintenance facilities. Waste petroleum, oil, and other lubricants; spent solvents; and waste or spilled fuels are sources of contamination in the area. Most of Area B has a cement cover; a few grassy areas exist. Currently, storm runoff drains into Clover Creek after passing through industrial separating units (Air Force Occupational and Environmental Health Laboratory [AFOEHL] 1990). Drainage of industrial waste runoff into Clover Creek was untreated until 1948. Figure 3, Appendix A, shows the site locations; Table B-4 lists information about the types of wastes disposed or spilled at Area B.
Table B-4. Waste History - Area B
| Site | Site Description | Wastes | Disposal/ Spill Dates |
| 38 | Liquid disposal/spill site along C ramp | Waste fuels and petroleum, oil, and lubricants (POL) disposal; 900 gallons of 1,500-gallon spill in 1980 were recovered | 1940s-1960s |
| 40 | Liquid disposal site | Waste POL; motor pool solvents | 1951-1960s |
| 41 | Fuel (AVGAS) spill | Reported fuel-line leak undetected for up to 6 months; quantity unknown; no recovery | 1965 |
| 47 | Fuel spill at C ramp | Reported 25,000 gallons fuel (type unknown) leaked from underground pipe; no recovery | Unknown |
| 52 | Spill site, Bldg. 1173 | Oil, synthetic lubricants, and hydraulic fluids | Unknown |
| 53 | Spill site, Bldgs. 1147 to 1159 |
Waste fuels, POL, and solvents; drainage through skimmer into storm drainage ditch connecting to Clover Creek | Unknown |
| 55 | Spill area between Bldgs. 1170 and 1164 | Fuels, POL, and solvents | Unknown |
Environmental Contamination
Groundwater at Area B has been analyzed during Stages 1 and 2 of the IRP Phase II Studies. Site hazard assessment of Sites 38, 40, 41, 53, and 55 in Area B was completed in June 1993.
Groundwater
During the IRP Phase II, Stage 1 investigations, five monitoring wells were installed that were completed in the surficial aquifer (maximum depth 102 feet). One well cluster, of which the deepest well was completed in the deeper aquifer, was also installed. The main report contains additional information about the Phase II, Stage I Study.
During Stage 2 of Phase II, no additional monitoring wells were built in Area A, but water samples from the wells installed during the Stage 1 investigations were analyzed. Refer to the main text of this public health assessment for additional information about the Phase II, Stage 2 Study.
VOCs and metals detected in the groundwater exceeded comparison values during both stages of the Phase II studies; pesticides were detected at levels exceeding comparison values during the Stage 2 study.
Two new monitoring wells were installed and sampled at Area B during the site hazard assessment. At Site 38, one new well (depth: 23 ft) was installed downgradient. Groundwater was sampled from the new well and from two existing upgradient wells. Samples were analyzed for total petroleum hydrocarbons compounds and volatile and semivolatile organic compounds. No contaminants that were detected exceeded the comparison values.
At Site 55, one new monitoring well was installed downgradient. Groundwater was sampled from the new well and from an existing upgradient well. Samples were analyzed for total petroleum hydrocarbon compounds and volatile and semivolatile organic compounds. No contaminants exceeded the comparison values.
Subsurface Soil
During site hazard assessment in 1993, three test pits were excavated to depths varying from 5 to 10 ft for each of four sites (Sites 38, 40, 41, and 53). One soil sample was collected from the base of each test pit. The samples were analyzed for total petroleum hydrocarbon compounds and volatile and semivolatile organic compounds. No contaminants that were detected exceeded the comparison values.
Also, during site hazard assessment, three soil borings were completed to depths of 8 to 15 ft at Site 55. One soil sample was collected from each soil boring and analyzed for total petroleum hydrocarbon compounds and volatile and semivolatile organic compounds. No contaminants that were detected exceeded the comparison values.
Area C
Sites 12, 33, 37, 42, 45, 57, 58, 61, and 62
Background
Area C, the middle portion of the industrial area at McCAFB, includes seven sites where waste petroleum, oils, lubricants, solvents, and fuels were either spilled or disposed. Another site (Site 33) was a former fire training area. In this public health assessment, Site 33 is also included in Area C because of geographic location and similar contamination. Most of Area C has a cement cover; a few grassy areas exist. Currently, storm runoff drains into Clover Creek after passing through industrial separating units (AFOEHL 1990). Drainage of industrial waste runoff into Clover Creek was untreated until 1948. Figure 3, Appendix A, shows site locations; Table B-5 lists information about the types of wastes disposed or spilled at Area C.
Table B-5. Waste History - Area C
| Site | Site Description | Wastes | Disposal/ Spill Dates |
| 12 | Landfill | Industrial and construction wastes, coal ash | 1939-1952 |
| 33 | Former fire fighter training area | Waste fuel (AVGAS) | 1940s-1950 |
| 37 | Liquid disposal site along "D" ramp |
Waste fuels and POL | 1940s-1960s |
| 42 | Liquid waste spill at refueling docks |
Waste POL and fuels | Unknown |
| 45 | Fuel spill between Hangars 1 and 2 | AVGAS spill of 2,000 gallons | 1950s |
| 57 | Leach pit near Hangar 1 | Industrial wastes, including POL, degreasers, other solvents, and electroplating wastes | Early 1980s |
| 58 | Leach pit (acid dry well) | Industrial wastes | 1950s-1970s |
| 61 | Leach pit between Bldg. 745 and Clover Creek | Electroplating wastes | 1953-1960 |
| 62 | Dump pad and infiltration area | Plating tank sludges; drainage to Clover Creek | Unknown |
Environmental Contamination
Groundwater at Area C has been analyzed during both Stages 1 and 2 of the IRP Phase II Studies. Site hazard assessment of Sites 12, 42, 57, 58, 61, and 62 was completed in June 1993. Two sites within Area C are included on the NPL as the Washrack/Treatment Area (WTA) Site. Contaminant information from the remedial investigation completed for that NPL site is addressed separately (WTA Site).
Groundwater
During the IRP Phase II, Stage 1 investigations, four monitoring wells were installed that were completed in the surficial aquifer (maximum depth 103 feet). One well cluster, of which the deepest well was completed in the deeper aquifer, was also installed. Refer to the main text of this public health assessment for additional information about the Phase II, Stage 1 Study.
During Stage 2 of Phase II, one additional monitoring well and four observation/recovery wells were installed in Area A. Water samples from the wells installed during both Phase II investigations were analyzed. Refer to the main text of this public health assessment for additional information about the Phase II, Stage 2 Study. Pesticides, VOCs, and metals were detected in the groundwater at levels exceeding comparison values during both stages of the Phase II studies.
Two new monitoring wells were installed and sampled at Area C during the site hazard assessment completed in June 1993. One well was installed upgradient (depth: 25 ft) and the other (depth: 33 ft) was installed downgradient of Site 12. None of the contaminants detected exceeded the comparison values.
Subsurface Soil
Subsurface soil samples were analyzed at Sites 42, 58, 61, and 62.
At Site 42, three test pits were excavated to a depth of 9 ft. One soil sample was collected from the base of each test pit; the three samples plus one duplicate were analyzed for total petroleum hydrocarbon compounds. No contaminants detected exceeded the comparison values.
At Site 58, one test pit was excavated to a depth of 6 ft in the acid leach pit. One soil sample was collected from the base of the test pit and analyzed for total petroleum hydrocarbon compounds, and priority pollutant metals. No contaminant concentrations exceeded the comparison values.
At Site 61, one near-surface soil sample was collected from the base of the leach pit from 0 to 6 in and analyzed for volatile and semivolatile organic compounds and priority pollutant metals. (ATSDR defines surface soil as soil 0-3 inches below the ground surface.) The concentrations of contaminants exceeding comparison values (or else not having comparison values) are summarized in Table B-7.
Table B-6. Range of Contaminant Concentrations in On-base Soil Sample - Area C, Site 61
| Contaminant | Range of Levels (ppm) |
Depth | Date | Reference | Comparison Value | |
| (ppm) | Source | |||||
| Arsenic | 5 | 0-6" | 1993 | EBASCO | 0.4 | CREG |
| Cadium | 439 | 0-6" | 1993 | EBASCO | 1 | Pica-child EMEG |
| Chromium | 828 | 0-6" | 1993 | EBASCO | None | Carcinogen |
| Copper | 55.8 | 0-6" | 1993 | EBASCO | None | |
| Lead | 3110 | 0-6" | 1993 | EBASCO | None | Carcinogen |
| Mercury | 0.11 | 0-6" | 1993 | EBASCO | None | |
| Nickel | 29.6 | 0-6" | 1993 | EBASCO | None | Carcinogen |
| Zinc | 650 | 0-6" | 1993 | EBASCO | 600 | Pica-child RMEG |
At Site 62, one test pit was excavated to a depth of 4.8 ft. One soil sample was collected from the base of the test pit and then analyzed for volatile and semivolatile organic compounds and priority pollutant metals. The concentrations of contaminant exceeding comparison values are summarized in Table B-6.
Table B-7. Range of Contaminant Concentrations in On-base Soil Sample - Area C, Site 62
| Contaminant | Range of Levels (ppm) |
Depth | Date | Reference | Comparison Value | |
| (ppm) | Source | |||||
| Arsenic | 2.3 | 4.8' | 1993 | EBASCO | 0.4 | CREG |
Sludge
At Site 57, a leach pit, the manhole cover was removed and one sample was collected from the base of the leach pit which contained about three feet of wet sludge. The sludge sample was analyzed by the Toxicity Characteristic Leaching Procedure to determine characteristics for potential disposal. Comparison values for sludge are not available. These metals were detected: cadmium (67 ppb), chromium (14 ppb), lead (190 ppb), and mercury (0.35 ppb).
Washrack Treatment Area (WTA)
NPL Site In Area C
Sites 54 and 60
Background
The WTA site is in the industrial and operational activity areas associated with aircraft maintenance and flight operation. The WTA was listed on the NPL in 1987. That site is the location of a washrack operation and includes the storm drainage infiltration ditches. Two IRP sites are in the vicinity of the WTA: Site 54, the washrack rinsate disposal area (two leach pits) where organic solvents used to clean airplanes were disposed; and Site 60, a plume of floating product. Groundwater studies in the immediate WTA area have documented a layer of fuel floating on top of the water table. That fuel layer is either diesel fuel or aviation fuel (AVGAS). Figure 3, Appendix A, shows the locations of the sites; Table B-8 lists information about the types of wastes disposed or spilled at WTA.
Table B-8. Waste History at WTA
| Site | Site Description | Wastes | Disposal/ Spill Dates |
| 54 | Liquid disposal/spill adjacent to washrack and including Industrial Waste Water Treatment Plant |
Solvents, alkaline-base detergents, paint removers, corrosion-removing compounds, degreasers, waste oils, and solvents; drainage of wastes into Clover Creek untreated until 1948; in 1968, total flow to leach pit was 8,000 gallons per day; problems with skimmer | 1940s-? |
| 60 | Leach pit and storm drainage infiltration ditches | Petroleum, oil, and lubricants | 1950s-? |
Sites 54 and 60 were included as part of Area C in the two IRP Phase II investigations (Stage 1 and 2) that were conducted in 1983 and 1984. Therefore, the environmental sampling information obtained from those investigations is included with Area C sampling information. Only the sampling information obtained during the Shannon and Wilson Conceptual Hydrocarbon Recovery Plan (CHRP) for Area C (specifically, Site 60) and the WTA RI study for Sites 54 and 60 is included here. Soil samples from two sites in the drainfield were analyzed by the AFOEHL in 1983 for metals; those data are referred to in the IRP Phase II study, but the original report was unavailable. Some of the non-NPL sites within Areas B and C were sampled for environmental contaminants during site hazard assessment to determine whether remediation or additional investigation is needed.
The selected remediation described in the record of decision for this site includes extracting, collecting, and removing the floating fuel in the unconfined aquifer. Site 54 is included in the long-term groundwater monitoring plan for the base.
Environmental Contamination
Two separate investigations have been conducted specifically at WTA: CHRP study (Shannon and Wilson Inc. 1986) and the RI (EBASCO Services Incorporated 1992a). One of the purposes of the CHRP study was to define the location and extent of the hydrocarbon layer floating on the water table at Area C (specifically, Site 60). Ten groundwater monitoring wells were installed to the lowest point of the surficial aquifer. Three groundwater samples were analyzed for priority pollutants.
During the RI, the WTA area was investigated using geophysical techniques, groundwater samples, surface soil samples, and subsurface samples. Field activities for the RI began in July and were completed in August 1991. Geophysical surveys (electromagnetic and ground-penetrating radar) were part of the RI investigation of suspected source areas. Areas of suspected contamination are shown in Figure 7, Appendix A.
Groundwater
Three groundwater samples from the surficial aquifer were analyzed during the CHRP investigation for VOCs, base neutral/acid extractable organic compounds (BNAs), and metals.
During the RI, groundwater under the WTA was investigated by sampling the shallow and deep groundwater wells (Figure 8, Appendix A). Three new shallow wells were installed near the leach pits; nine deeper wells were installed at three other locations. Samples of groundwater were collected from the 12 new and 14 existing wells during four quarterly sampling rounds. Samples taken during Rounds 1, 3, and 4 were analyzed for VOCs, TPHs, BNAs, pesticides, polychlorinated biphenyls (PCBs), and metals. During Round 2, all well samples were analyzed for VOCs and metals; some were analyzed for TPHs, semi-volatile compounds, and polycyclic aromatic hydrocarbons (PAHs). Wells in the WTA area are screened in three of the four designated aquifers.
Analytical data for the two investigations of groundwater in Area C specific to WTA are included in Tables B-9 and B-10. Groundwater data obtained during the CHRP study are specific to Site 60.
Table B-9. Organic Contaminant Concentrations in On-Base Groundwater Monitoring
Wells - WTA
| Groundwater Contaminants | Range of Levels (ppb) |
Date | Reference | Comparison Value | |
| (ppb) | Source | ||||
| Benzene | trace BDL-7.6 |
1986 1990-1991 |
CHRP EBASCO RI |
1.2 | CREG |
| Bis(2-ethylhexyl)phthalate | 28-1,500 | 1986 | CHRP | 2.5 | CREG |
| Total noncarcinogenic PAHs | 394-9,280 BDL-12.5 |
1986 1990-1991 |
CHRP EBASCO RI |
None | None |
| Total carcinogenic PAHs | BDL-1.70 | 1990-1991 | EBASCO RI | None | EPA-Carcinogens |
| Dibenzofuran | BDL-140 BDL-1 |
1986 1990-1991 |
CHRP EBASCO RI |
None | None |
| Dichloromethane | 27-74 | 1986 | CHRP | 4.7 | CREG |
| Fluorene | 27-550 | 1986 | CHRP | 400 | RMEG-Child |
| 2-Methylnaphthalene | 300-27,000 | 1986 | CHRP | None | None |
| Naphthalene | 40-4,900 | 1986 | CHRP | 20 | LTHA |
| N-nitrosodiphenylamine | BDL-7,900 | 1986 | CHRP | 500 | EMEG |
| Trichloroethylene | BDL-0.5 | 1990-1991 | EBASCO RI | 3.2 | CREG |
Table B-10. Inorganic Contaminant Concentrations in On-base Groundwater Monitoring
Wells - WTA
| Groundwater Contaminants | Range of Levels (ppb) |
Date | Reference | Comparison Value | |
| (ppb) | Source | ||||
| Aluminum | BDL-177,000 | 1990-1991 | EBASCO RI | None | None |
| Antimony | BDL-16.4 | 1990-1991 | EBASCO RI | 4 | RMEG-Child |
| Arsenic | 25-30 BDL-49 |
1986 1990-1991 |
CHRP EBASCO RI |
0.02 | CREG |
| Barium | BDL-1,710 | 1990-1991 | EBASCO RI | 700 | RMEG-Child |
| Cadmium | 4-14 BDL-7 |
1986 1990-1991 |
CHRP EBASCO RI |
2 | EMEG-Child |
| Chromium | 46-330 BDL-107 |
1986 1990-1991 |
CHRP EBASCO RI |
None | DHHS-Carcinogen |
| Lead | 220-260 85.9 |
1986 1990-1991 |
CHRP EBASCO RI |
None | EPA-Carcinogen |
| Manganese | 4.5-2,000 | 1990-1991 | EBASCO RI | 50 | RMEG-Child |
| Nickel | 27-300 BDL-335 |
1986 1990-1991 |
CHRP EBASCO RI |
100 | PMCLG |
| Selenium | BDL | 1990-1991 | EBASCO RI | 30 | EMEG-Child |
| Silver | 1-10 BDL-11 |
1986 1990-1991 |
CHRP EBASCO RI |
50 | RMEG-Child |
| Thallium | BDL-1.25 | 1990-1991 | EBASCO RI | 1 | LTHA |
| Vanadium | BDL-463 | 1990-1991 | EBASCO RI | 20 | LTHA |
| Zinc | 4.4-4,818 | 1990-1991 | EBASCO RI | 2000 | LTHA |
Near-Surface Soil (0-6 inches)
No soil samples were analyzed during the CHRP investigation, but hydrocarbon-stained soil above the water table was encountered during installation of six of the monitoring wells during this study.
The 14 soil locations sampled at WTA during the RI were chosen because of previous aerial photo data, information on past waste disposal practices, results of geophysical surveys, and field reconnaissance of the site. Twelve samples were collected (at depths from 0-6 inches) representing the 14 locations (two were composite samples). (ATSDR defines surface soil as soil 0-3 inches below the ground surface.) The soil samples were analyzed for VOCs, TPH, semi-volatile compounds (including PAHs), pesticides, PCBs, and metals. None of the detected contaminants, except arsenic, were at levels exceeding their respective comparison values. The concentration for lead is included in Table B-11 because comparison values for lead are not currently available.
Table B-11. Range of Contaminant Concentrations in On-base Near-Surface Soil Samples - WTA Site
| Contaminant | Range of Levels (ppm) |
Depth (inches) |
Date | Reference | Comparison Value | |
| (ppm) | Source | |||||
| Arsenic | 1-110 | 0-6 inches | 1990-1991 | EBASCO RI | 0.4 | CREG |
| Lead | 3.3-439 | 0-6 inches | 1990-1991 | EBASCO RI | None | EPA-Carcinogen |
Subsurface Soil
Subsurface soil samples from two sites in the drainfield were analyzed in 1983 by the AFOEHL for metals. The original data were not available, but were referred to in the Phase II, Stage 1 study. High levels of some heavy metals were detected in soils one foot below the ground surface during the AFOEHL study, but those levels were not duplicated during the RI. Six subsurface soil samples were collected during the RI for chemical analysis in and around the suspected source areas at WTA. The soil samples were analyzed for VOCs, TPHs, semi-volatile compounds (including PAHs), pesticides, PCBs, and metal. None of the detected contaminants, except arsenic and cadmium, were at levels exceeding their respective comparison values. Leach pit samples accounted for 39 of a total of 40 detections. The total concentrations of noncarcinogenic PAHs are shown in Table B-12. The concentration of lead in the soil is also included in Table B-12 because comparison values for the metal currently are not available.
Table B-12. Range of Contaminant Concentrations in On-base Subsurface Soil Samples - WTA
| Contaminant | Range of Levels (ppm) |
Depth (inches) |
Date | Reference | Comparison Value | |
| (ppm) | Source | |||||
| Arsenic | up to 2.7 | 6 | 1990-1991 | EBASCO RI | 0.4 | CREG |
| Cadmium | up to 23.8 | 6 | 1990-1991 | EBASCO RI | 0.4 | EMEG-Pica Child |
| Total Noncarcinogenic PAHs | BDL-19,700 | 6 | 1990-1991 | EBASCO RI | None | None |
| Lead | 4-166 | 6 | 1990-1991 | EBASCO RI | None | EPA-Carcinogen |
Surface Water and Sediment Samples
During the RI, surface water and associated sediment samples were collected from three locations in Clover Creek, the surface water body associated with the site. Clover Creek is a perennial stream just west of WTA that provides the only surface water drainage for McCAFB. Samples were collected during three of the four sampling rounds. Three surface water samples and three sediment samples were collected for each water and sediment sampling round at the locations shown in Figure 9, Appendix A. The surface water samples were collected from the approximate center of the drainage route and as close to the bottom as could physically be reached. Surface water sediment samples were collected at the same locations as the surface water samples. Both types of samples were analyzed for VOCs, TPHs, semi-volatile compounds, PAHs, and metals (antimony, arsenic, beryllium, cadmium, chromium, cobalt, and manganese). Surface water and sediment sampling results are included in Tables B-13 and B-14.
| Contaminant | Range of Levels (ppb) |
Date | Reference | Comparison Value* | |
| (ppb) | Source | ||||
| Benzene | BDL-0.1 | 1990-1991 | EBASCO RI | 1.2 | CREG |
| Tetrachloroethylene | BDL-0.2 | 1990-1991 | EBASCO RI | 0.7 | CREG |
| Benzo(a)fluoranthene | BDL-0.02 | 1990-1991 | EBASCO RI | None | EPA- Carcinogen |
| Indeno(1,2,3-cd)pyrene | BDL-0.2 | 1990-1991 | EBASCO RI | None | EPA- Carcinogen |
| Total carcinogenic PAHs | BDL-0.2 | 1990-1991 | EBASCO RI | 4 | RMEG-Child |
| Contaminant | Range of Levels (ppm) |
Date | Reference | Comparison Value | |
| (ppm) | Source | ||||
| Benzene | BDL | 1990-1991 | EBASCO RI | 24 | CREG |
| Tetrachloroethylene | BDL | 1990-1991 | EBASCO RI | 7000 | RMEG-Adult |
| Chrysene | BDL-2.2 | 1990-1991 | EBASCO RI | None | EPA-Carcinogen |
| Benzo(a)anthracene | BDL-3 | 1990-1991 | EBASCO RI | None | EPA-Carcinogen |
| Benzo(b)fluoranthene | BDL-4.2 | 1990-1991 | EBASCO RI | None | EPA-Carcinogen |
| Benzo(k)fluoranthene | BDL-2 | 1990-1991 | EBASCO RI | None | EPA-Carcinogen |
| Benzo(a)pyrene | BDL-2.8 | 1990-1991 | EBASCO RI | 0.096 | CREG |
| Dibenzo(ah)anthracene | BDL-1.1 | 1990-1991 | EBASCO RI | None | EPA-Carcinogen |
| Indeno(1,2,3-cd)pyrene | BDL-1.8 | 1990-1991 | EBASCO RI | None | EPA-Carcinogen |
| Total carcinogenic PAHs | BDL-14.5 | 1990-1991 | EBASCO RI | None | EPA-Carcinogen |
| Total noncarcinogenic PAHs | 0.38-11.57 | 1990-1991 | EBASCO RI | None | None |
| Antimony | BDL-2.6 | 1990-1991 | EBASCO RI | 280 | RMEG-Adult |
| Arsenic | BDL-1.8 | 1990-1991 | EBASCO RI | 0.4 | CREG |
(Although several metals were detected in the groundwater at WTA at levels exceeding their respective comparison values, only antimony and arsenic were detected in the surface water at Clover Creek at levels exceeding comparison values for drinking water.)
Area D/American Lake Garden Tract (ALGT) Site
NPL Site
Sites 4, 5, 6, 7, 26, 35, 39
Background
The Area D/American Lake Garden Tract (Area D/ALGT) site includes the off-base ALGT, a residential area, and the southwestern part of McCAFB, designated Area D. The residential area lies southwest and immediately adjacent to Area D. Area D is bounded by Interstate 5 and Porter Hills on the northwest and north; by the McChord AFB ammunition storage area, "A" Street, and Burlington Northern Railroad tracks on the east; and the Fort Lewis Logistics Center on the south and southwest. The total site area comprises approximately 1,280 acres, of which about 940 acres is part of McChord AFB and about 340 acres is in the adjoining ALGT. The Whispering Firs Golf Course was built over the landfills in Area D. The first nine holes of the golf course were built in the 1950s; the second nine holes were added, east of the first nine, in the early 1970s.
Seven of the potential sources of contamination identified in the IRP Phase I records search were investigated as part of the Area D/ALGT NPL site in the RI. Figure 3, Appendix A, shows the site locations; Table B-15 lists information about the types of wastes disposed or spilled in this area.
Table B-15. Waste History - Area D/ALGT Site
| Site | Site Description | Wastes | Disposal/ Spill Dates |
| 4 | Gravel pit | Rubbish, garbage, and industrial wastes | 1941-1978 |
| 5 | Landfill under golf course | Large quantities of hazardous wastes, including waste oil and fuel | 1951-1967 |
| 6 | Landfill | Construction wastes | 1961-? |
| 7 | Landfill under golf course | Industrial, domestic, and construction wastes | 1967-1972 |
| 26 | Ordnance disposal | Residue from ordnance deactivation; 500 live grenades were reported to have been buried in area | 1943-1956 |
| 35 | Liquid radioactive disposal well (depth unknown) | Washwater from decontamination of radar components, fluorescent dials, possibly medical waste liquids; all disposed down a well | 1950s |
| 39 | Liquid waste disposal site adjacent to golf course | Waste fuel (JP-4), solvents, and POL were burned | 1956-1960 |
Contamination in the McChord ALGT area was first identified in April 1983. A local resident had complained of contaminated groundwater from her domestic well; water from the well was found to be contaminated with TCE and trans-1,2-DCE. In 1983, EPA determined that several other private wells in ALGT also were contaminated with TCE and trans-1,2-DCE (ATSDR 1992e). Although the trans isomer was believed to be the 1,2-DCE isomer in the early 1980s studies, the DCE contamination later was determined to be cis-1,2-DCE (EBASCO Environmental 1991a). Neither isomer is classified as a carcinogen; the cis isomer is slightly more toxic than the trans isomer. Another study conducted by EPA indicated the presence of TCE and cis-1,2-DCE in groundwater samples from monitoring wells installed in that portion of the ALGT (Ecology and Environment Inc. 1984). The contamination was later confirmed by additional monitoring well installation and sampling during studies under the IRP. The off-base information described here is discussed more fully in the off-base contamination section of the main text of this public health assessment.
The Area D/ALGT site was proposed for the NPL in September 1983 and was placed on the list in September 1984. The Air Force, EPA, and the Washington State Department of Ecology entered into a federal facility agreement in August 1989, which governs the conduct of the investigation of NPL sites on McChord AFB.
Soil contamination still exists at Sites 5 and 39 and 7; all are former landfills under the golf course (EBASCO Environmental 1991a). (Because of proximity, Sites 5 and 39 are addressed as one site in the RI.) The RI reported that secondary sources of TCE and cis-1,2-DCE contamination appear to be acting as a continuing source of groundwater contamination. None of the RI investigations located any of the secondary sources, but higher contaminant concentrations in some of the wells indicated their presence.
The ROD states that the seven IRP sites within Area D do not require source control. Site 5 will remain active to track the remediation of the aquifer; the six other IRP sites have been proposed for "no further action" (NFA).
One of those NFA-proposed sites is Site 26, the Ordnance Disposal Area. Site 26 is near the golf course and, although part of it is fenced as a part of the active and patrolled ammunition storage area, most of it is not. In 1972, a metal detector survey was conducted at the site for residual debris remaining from historic ordnance disposal (EMB 1991b). Another metal detector survey that was conducted during the RI addressed only areas that were readily accessible; most of the site is covered with dense vegetation (EBASCO Environmental 1991a). Many items were detected, uncovered, and identified for appropriate disposal. Among the items detected were three nose fuses for 2.75-inch-high explosive fragmentation bombs and several grams of explosive material loose in the soil within some fusing. The results of the survey indicated that perhaps one pile of 2.75-inch-high explosive ordnance was improperly detonated from the bottom, resulting in spread of the material. The area undoubtedly contains additional unexploded ordnance and explosive material not located at the time of this survey (EBASCO Environmental 1991a). McCAFB believes that Site 26 has been comprehensively surveyed and that nearby Baxter Lake remains the only location within the site that has not been traversed with metal detectors (EMB 1991b). McCAFB has proposed this site for no further action and inclusion within the Area D/ALGT long-term groundwater monitoring program.
Environmental Contamination
Chemical analyses of groundwater were conducted for Area D during both stages of the IRP Phase II Study. During the RI for Area D/ALGT, groundwater sampling was conducted both on base (Area D) and off base (ALGT). The on-base environmental sampling results are discussed here; the off-base sampling results are discussed in the main text of this public health assessment. In addition to the groundwater data, sampling data are also available in the RI for soil, surface water, sediment, and soil gas. In January 1992, some of the wells used during the RI were resampled and analyzed for VOCs as part of the first round of the continuing monitoring process.
Soil Gas
Soil gas surveys were performed during the RI to help characterize the types and extent of contamination in the soil. A total of 256 environmental samples from seven suspected source areas (Sites 4, 6, 7, 5&39, and three places at Site 26) were analyzed in the field for six contaminants (TCE, trans-1,2-DCE, cis-1,2-DCE, PCE, benzene, and toluene). TCE and cis-1,2-DCE contamination is listed by site in Table B-16.
Table B-16. TCE and cis-1,2-DCE Contamination in Soil Gas - Area D
| Site | Number of Locations Sampled |
Trichloroethylene | Cis-1,2-Dichloroethylene | ||
| No. of Detections | (ppb) | No. of Detections | (ppb) | ||
| 4 | 24 | 0 | BDL | 13 | 6-550 |
| 5&39 | 96 | 37 | 0.4-85,000 | 45 | 0.5-19,000 |
| 6 | 42 | 11 | 2-18 | 0 | BDL |
| 7 | 72 | 43 | 7-86,000 | 32 | 2-40,000 |
| 26-A | 7 | 0 | BDL | 0 | BDL |
| 26-C | 5 | 0 | BDL | 0 | BDL |
| 26-D | 10 | 2 | 2-50 | 1 | 5.2 |
A methane screening also was performed at the Site 6 landfill during the RI. OVA and explosimeter results suggested that methane might be migrating from the landfill at Site 6 east towards a day care center; northeast towards the eastern side of another building (SAGE) next to the gas fuel tanks; and south towards the Fort Lewis (EBASCO Environmental 1991a). Additional field investigations were conducted as part of the RI to further characterize any methane migration from this landfill. These results were discussed in an RI addendum report because they were not available when the RI was made final (EBASCO Environmental 1991f). In May 1990, two sets of double gas migration probes were installed on the margins of the SAGE Landfill. The gas migration probes were sampled twice in 1991 for methane and other VOCs. No methane was detected in any of the probe samples during either sampling round; VOCs did not exceed 1 ppm in any samples.
Groundwater
The on-base (Area D) groundwater contamination in the Area D/ALGT Site is discussed here; the off-base (ALGT) contamination is discussed in the main text of this public health assessment. The IRP Phase II, Stages 1 and 2 base-wide groundwater studies have been described in the main report. In Area D, two monitoring wells were sampled during Phase I, Stage 1; three additional monitoring wells were installed and sampled during Phase I, Stage 2. ATSDR has excluded the Phase II groundwater contaminant data for Area D/ALGT from the public health assessment because more recent environmental data are available in the RI and in a 1992 technical memorandum.
During the RI, 45 previously installed monitoring wells, 73 newly installed monitoring wells, and six base water supply wells were sampled. No private wells in ALGT were sampled during the RI. Fifty-seven of the 73 new wells were installed as shallow wells to investigate the contamination in the unconfined aquifer. All groundwater samples were analyzed for TCE and the cis- and trans-isomers of cis-1,2-DCE. A subset of the samples were also analyzed for the full set of VOCs. Besides VOCs, 17 groundwater samples were analyzed for metals and cyanide, acid/base/neutral extractable compounds, pesticides, and PCBs. A subset of the 17 samples was analyzed for organophosphorus pesticides. One sample from the monitoring well closest to the radioactive disposal well (Site 35) was also scanned for gross alpha, gross beta, Cs 137, Ra 226, K 40, Th 228, and Th 232. When duplicate samples were taken from a well during a sampling round, the results were averaged. The monitoring well samples from the ALGT residential area were tested only for TCE and cis-1,2-DCE.
The final groundwater sampling for the RI was completed in September 1990. Twenty of the monitoring wells sampled during the RI were resampled for full-range VOC analysis in January 1992 to determine if the TCE and cis-1,2-DCE plumes had changed or spread. Two of the 20 wells are in the ALGT. Groundwater contaminant concentrations in Area D exceeding comparison values are shown in Table B-17. Almost always, the 1,2-DCE detected was found to be the cis-isomer. Figure 10 shows the TCE contamination plume and waste sites. Site-specific concentrations of TCE and cis-1,2-DCE in groundwater are listed in Table B-18.
Table B-17. Contaminant Concentrations in On-Base Groundwater Monitoring Wells - Area D
| Groundwater Contaminants | Range of Levels (ppb) |
Date | Reference | Comparison Value | |
| (ppb) | Source | ||||
| Benzene | BDL-1.4 | 1990-1991 | EBASCO RI | 1.2 | CREG |
| Bromodichloromethane | BDL-1.3 | 1992 | EBASCO Technical Memorandum |
0.27 | CREG |
| Cis-1,2-Dichloroethylene | BDL-320 BDL-196 |
1990-1991 1992 |
EBASCO RI EBASCO Technical Memorandum |
70 | LTHA |
| Chloroform | BDL-6.8 | 1992 | EBASCO Technical Memorandum |
5.7 | CREG |
| Chloromethane | BDL-4.8 | 1992 | EBASCO Technical Memorandum |
3 | LTHA |
| Dichloromethane | BDL-34 BDL-10 |
1990-1991 1992 |
EBASCO RI EBASCO Technical Memorandum |
4.7 | CREG |
| Trichloroethylene | BDL-88 BDL-96.3 |
1990-1991 1992 |
EBASCO RI EBASCO Technical Memorandum |
3.2 | CREG |
| Vinyl Chloride | BDL-1.8 | 1990-1991 | EBASCO RI | 0.2 | EMEG-Child |
| Arsenic | BDL-24 | 1990-1991 | EBASCO RI | 0.02 | CREG |
| Barium | BDL-1,280 | 1990-1991 | EBASCO RI | 700 | RMEG-Child |
| Cadmium | BDL-8 | 1990-1991 | EBASCO RI | 2 | EMEG- Child |
| Chromium | BDL-103 | 1990-1991 | EBASCO RI | None | DHHS-Carcinogen |
| Lead | BDL-78 | `1990-1991 | EBASCO RI | None | EPA-Carcinogen |
| Site | Contaminant | Concentration (ppb) |
Location | Date | Comparison
Value (ppb) |
Comparison
Value Source |
| 4 | TCE | BDL | 3.2 | CREG | ||
| cis-1,2-DCE | BDL | 70 | LTHA | |||
| 5&39 | TCE | 88 | DA-07b | 3/90 | 3.2 | CREG |
| cis-1,2-DCE | 320 | DA-07b | 5/89 | 70 | LTHA | |
| 6 | TCE | BDL | 3.2 | CREG | ||
| cis-1,2-DCE | BDL | 70 | LTHA | |||
| 7 | TCE | 5.5 | DB-02 | 11/89 | 3.2 | CREG |
| cis-1,2-DCE | 8 | DB-02 | 11/89 | 70 | LTHA | |
| 26 | TCE | 19 | DB-06 | 5/89 | 3.2 | CREG |
| cis-1,2-DCE | 22 | DB-06 | 5/89 | 70 | LTHA | |
| 35 | TCE | 1.2 | DB-11 | 8/89 | 3.2 | CREG |
| cis-1,2-DCE | BDL | 70 | LTHA |
Background Near-Surface Soil Samples
Background soils were sampled at 27 locations around McCAFB and analyzed for metals. Background samples were taken from the surface to 6 inches below, except for one boring for which five samples were analyzed at varying depths to 19.5 feet. (ATSDR defines surface soil as soil 0-3 inches below the ground surface.) The locations were selected where there appeared to have been no disturbances during the past several decades that might contaminate the samples. The concentration of arsenic in all 25 samples (ranging from 2.6-18 ppm) exceeded the comparison value (0.4 ppm, CREG). No other comparison values were exceeded. The maximum concentration of lead was 214 ppm; no comparison value is available for lead.
Subsurface Soil
Thirty hollow-stem auger boreholes were drilled and sampled. The locations selected were primarily from areas with high contaminant concentrations during the soil gas survey.
All 86 subsurface soil samples were analyzed for TCE, cis-1,2-DCE, and trans-1,2-DCE. No surface samples were analyzed. Samples were analyzed for full volatile gas chromatography/mass spectroscopy (GC/MS) analysis whenever field investigations indicated the existence of possible contamination, such as visible staining and detection of organic vapor emissions.
No VOCs were found at concentrations exceeding their respective comparison values. Although several semi-volatile compounds and pesticides were detected, the concentrations did not exceed their respective comparison values.
Eight source area subsurface soil samples were analyzed for metals. The concentrations of metals in those samples were less than the maximum values determined for the background samples, except for cadmium, mercury, and zinc. The concentrations of those analytes were not above their respective comparison values. All source area samples were taken at various depths, ranging from 12.5 to 20.0 feet below the surface.
Radioactive parameters (gross alpha, gross beta, Cs 137, Ra 226, K 40, Th 228, and Th 232) for soil samples from five depths of a boring at Site 35 were checked for possible residual contamination remaining from disposal of low-level radioactive waste. Radioactivity measurements made during drilling and the results of the analyses do not indicate any radioactivity other than that occurring naturally.
Surface Water and Sediment
Surface water and sediment samples from seven water bodies in Area D were analyzed for TCE, cis-1,2-DCE, metals, and pesticides. No comparison values are available for surface water. Metals were detected at naturally-occurring levels. The concentrations of lead in sediment ranged between 2.8 and 318 ppm.
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