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1. ATSDR > Public Health Assessments & Consultations

PUBLIC HEALTH ASSESSMENT

NAVAL AIR STATION WHIDBEY ISLAND (AULT FIELD AND SEAPLANE BASE)
OAK HARBOR, ISLAND COUNTY, WASHINGTON

ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS

A. Introduction

The contaminants discussed in subsequent sections of this public health assessment are evaluated to determine whether exposure has occurred, and if so, whether that exposure has public health significance. ATSDR selects and discusses contaminants using the following information:

• concentrations of contaminants on and off site;



• the quality of the field and laboratory data and sample design;



• comparison of on- and off-site concentrations with comparison values for noncancer and cancer endpoints; and



• community health concerns.

The listing of a contaminant in the following tables does not mean that it will cause adverse health effects if exposure occurs at the specified concentrations. Rather, the listing of a contaminant indicates that it will be discussed further in this public health assessment. The potential for adverse health effects resulting from exposure to contaminants of concern is discussed in the Public Health Implications section of this document. When a contaminant exceeds comparison values in one medium, it will be discussed or listed in the tables for all media. Most of the comparison values in this document are based on adult ingestion rates and body weights, since most of the areas under investigation are visited by adults. Comparison values for children are lower than those for adults. ATSDR uses lower comparison values when children at a site could be exposed to contaminants in a specific media; residential areas and elementary schools are examples of sites where lower comparison values may be used.

Comparison values for ATSDR public health assessments are contaminant concentrations in specific media that are used to select contaminants for further evaluation. ATSDR and other agencies developed the values to provide guidelines for estimating the media concentrations of a contaminant that are unlikely to cause adverse health effects, given a standard daily ingestion rate and standard body weight.

These abbreviations are used in the following tables:

Background Concentrations

Background levels in local soil and water may be greatly influenced by high levels of chemicals from native mineral deposits or other natural sources. Background levels could be anthropogenic (e.g., gravel for a road or parking lot) substances in the environment due to human-made, non-site sources. If contaminants detected on site are below background concentrations, but exceed applicable comparison values, ATSDR will list them in the data tables to follow and evaluate whether exposure to them is of public health concern.

B. On-Site Contamination

RI reports and other investigation reports are written throughout the IRP process, and media monitoring and sample analyses in each phase generated new data for each site under investigation. Sometimes, the data used in the discussions that follow came from draft copies of IRP reports. Data qualifiers that were in the IRP reports were carried to the tables below. Where the IRP reports noted the data had not received quality assurance/quality control review, the appropriate data or tables are footnoted with statements to that effect.

The public comment release of the NAS Whidbey Public Health Assessment included data from documents through 1992. For this release, ATSDR reviewed the latest RI reports through June 1993. However, the data tables in this section were not amended since the data did not change conclusions and recommendations and the tables serve only as an overview of the contaminated areas. Appropriate changes were made in the conclusions and recommendations due to proposed remedial actions.

Areas under investigation are grouped into Operable Units (OU), OU1 to OU5 and the Hazardous Waste Evaluation Study (HWES). During the Current Situation Report (CSR), HWES, and Remedial Investigations (RI) of the OUs, soil, sediment, surface water, and groundwater analyses included metals and cyanide, VOCs, semivolatile organic compounds (SVOCs), pesticides, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and pesticides. During the RI for OU3, fish and shellfish will be sampled and tested. Shellfish will be sampled during RI field work for OU4 (14).

Operable Unit 1

OU1 consists of Area 5, the Highway 20/Hoffman Road Landfill and Area 6, Landfill (Appendix A, Figure 3). These areas are grouped because both served as main facility landfills, are close to each other, and are above the same aquifer recharge area. The types of contaminants detected during the 1991 and 1992 RI investigations at OU1 are shown in Table 9.

Soil, sediment, surface water, and groundwater analyses included metals and cyanide, VOCs, SVOCs, pesticides, PCBs, organophosphorus pesticides, and chlorinated herbicides. The Navy sampled soil gas, ambient air, and particulates at Area 6.

At Area 5, VOCs were detected in surface water and shallow groundwater, SVOCs in subsurface soil, pesticides in sediment, and inorganics in sediment, surface soil, subsurface soil, surface water, and shallow groundwater. At Area 6, VOCs were detected in soil gas, air, surface soil, subsurface soil, surface water, and shallow, intermediate, and deep groundwater. SVOCs were detected in air, surface sediment, and shallow groundwater, and pesticides in sediment and shallow and deep groundwater. Heavy metals were detected in air, surface sediment, surface soil, subsurface soil, surface water, and shallow, intermediate, and deep groundwater.

Table 9. Summary of Detected Compounds in Operable Unit 1 (6)

Media	Class of Compound
	VOC	SVOC	Pesticides	PCB	PAH	Metals
Soil Gas	•	n/a	n/a	n/a	n/a	n/a
Air	•	•	n/a	n/a	n/a	•
Sediment	•	•	•	o	o	•
Surface Soil	•	•	•	o	•	•
Subsurface Soil	•	•	o	o	o	•
Surface Water	•	o	o	o	o	•
Groundwater	•	o	•	o	•	•
• detected o not detected n/a not analyzed

OU1 Waste

At Area 6, the Navy tested liquid waste from the former hazardous waste storage area in March 1981 as part of the Initial Assessment Study (IAS). The former hazardous waste storage area is in Area 6, where the groundwater plume is suspected to originate. The liquid waste contained barium (690 parts per billion [ppb]), cadmium (1400 ppb), total chromium (11,100 ppb), chromium VI (< 5 ppb), lead (9200 ppb), mercury (2 ppb), nickel (430 ppb), zinc (2700 ppb), and phenol (750,000 ppb).

OU1 Surface Soil

ATSDR considers soil taken from a depth equal to or less than 3 inches (<3") as surface soil. People are most likely to be exposed to soil from that layer by ingestion or dermal contact. Table 10 lists the contaminant concentrations in on-site surface soil. Additional OU1 surface soil samples were taken to a depth of 2 centimeters (cm) during the Interim Action (27) and RI Phase I (6).

During the RI, three surface soil samples were collected during the installation of three wells at Area 5. Detected contaminants were below comparison values for soil. At Area 6, 39 surface soil samples were analyzed. The Navy always found VOC contamination within 500 feet of the former hazardous waste storage area (6). Cyanide and 15 of 18 metals were detected, generally near the hazardous waste storage area and the Area 6 landfill. The maximum concentration for beryllium came from a single sample on Area 6 near the hazardous waste storage area (Table 10) (10). ATSDR has not developed ingestion and dermal contact comparison values for concentrations of lead, nickel, and vanadium that are detected in soil or sediment.

Table 10. Contaminant Concentrations at Operable Unit 1

OU, Area	Contaminant	Min&Max Level for Each Contaminant	Reference AII-6/90, RI-7/91	Comparison Value, mg/kg	Source
On-Site Surface Soil, mg/kg
OU1, 5	Lead	4.5-31.6J	AII, RI/FS	None
	Nickel	18J-36	RI/FS	None
	Vanadium	28.1	RI/FS	None
OU1, 6	Beryllium	0.3-378.7	RI/FS	0.16	CREG
	Lead	3.1-63	AII, RI/FS	None
	Carc. PAH	0.040-0.22	RI/FS	0.12	CREG (BaP)
On-Site Sediment, mg/kg
OU1, 5	Lead	4.5-8.3	RI/FS	None
	Nickel	18.2-148	RI/FS	None
	Vanadium	16.9-53.8	RI/FS	None
OU1, 6	Heptachlor epoxide	ND-0.42	RI/FS	0.16	CREG
	Aldrin	ND-0.077	RI/FS	0.041	CREG
	Lead	1.6BJ-19.7J	RI/FS	None
	Nickel	31J-89.1J	RI/FS	None
	Vanadium	15.7-45.8	RI/FS	None
Notes: J - Contaminant was positively identified; estimated concentration B - Metals: Contaminant detected at less than contract required detection limit, but greater than the instrument detection limit B - Organics: Contaminant detected in associated laboratory blank ND - Not detected Carc. PAH (carcinogenic PAHs) - benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, ideno(1,2,3-cd)pyrene BaP - Benzo(a)pyrene, a carcinogenic PAH Sediment samples for Area 5 were taken from the wetland area to the west.

OU1 Sediment

There are no wetlands or surface water within Area 5, so sediment samples were taken from a wetland 1000 feet west of the area. Eleven sediment samples were collected and analyzed. Sediment from the eastern edge of the wetland close to the border of NAS contained metals and a pesticide below comparison values (28).

At Area 6, samples were taken from the intermittent stream within the area at five stations during the Interim Action and during the RI. Samples of surface sediment were analyzed for VOCs and inorganic compounds. At selected locations, samples were analyzed for SVOCs, pesticides, PCBs, organophosphorus pesticides, and chlorinated herbicides (28). Metals and pesticides were detected in sediment at Area 6 (Table 10) in samples taken from the ephemeral (intermittent) stream that flows north toward Area 5. Most of the pesticides detected were from a single station in the northwest part of Area 6 (28). Lead, nickel, and vanadium in sediment have no comparison values for ingestion or dermal contact.

OU1 Subsurface Soil

ATSDR considers soil from depths greater than 3 inches (>3") as subsurface soil. Subsurface soil samples were collected when monitoring wells were drilled and from soil borings. Contaminants found in subsurface soil samples do not necessarily reflect surface soil contamination.

At OU1 Area 6, 35 samples were collected for chemical analysis. Soil samples were collected at 5-foot intervals from bore holes to a depth of 50 feet and in screen zone for all wells. VOCs were generally found in subsurface soils near the former hazardous waste storage area (6). Low levels of chloroform (0.004-0.008 mg/kg) were detected down to 201 feet and were below comparison values.

Cadmium (472 mg/kg) was detected above comparison values at a depth of 20 feet in a soil sample from a bore hole near the hazardous waste storage area (10). Cadmium was not detected at that level in any other sample.

OU1 Soil Gas

A total of 223 soil gas samples were collected from January to July 1991. The soil gas samples were used to position monitoring well, soil boring, and surface soil sampling points. The highest soil gas concentrations were in Area 6 near the former hazardous waste storage area and northwest of the hazardous waste storage area (trichloroethylene-60,000 ppb, 1,1-dichloroethane-97,000 ppb, 1,1-dichloroethene-5000 ppb). Other locations of high concentrations of VOCs were to the northeast and north of the hazardous waste storage area (benzene-25,000 ppb, tetrachloroethylene-1700 ppb). The Navy detected soil gas northwest of the western boundary of Area 6 and NAS within 800 feet from the hazardous waste storage area (benzene-630 ppb, tetrachloroethylene-690 ppb, 1,1-dichloroethane-15,000 ppb, 1,1-dichloroethene-450 ppb) (6). Currently, no structures are located at or near Area 5 or Area 6, therefore the only potential is if such structures are built. Since OU1 consist of landfills, it is unlikely that it will be developed for future residential use and an industrial scenario may also be unlikely. The Code of Federal Regulations, Volume 40, Part 258 ("EPA Criteria for Municipal Solid Waste Landfills (MSWLFs)"), Subpart F ("Closure and Post Closure Care"), paragraph 258.60 (i) (1) and (2) state that "Following closure of all MSWLF units, the owner or operator must record a notation on the deed to the landfill facility property...The notation of the deed must in perpetuity notify any potential purchasers of the property that: (i) the land has been used as a landfill facility; and (ii) its use is restricted under paragraph 258.61 (c) (3)." Paragraph 258.61 (c) (3) states that "Post closure use of the property shall not disturb the integrity of the final cover, liner(s), or any other components of the contaminant system, or the functioning monitoring system."

OU1 Surface Water

Since there are no comparison values for surface water, drinking water comparison values were used. There is no surface water in Area 5. A wetland to the west of the Area 5 was sampled. Samples from three points on the northeastern, eastern, and southern edge of the wetland detected VOCs and metals. The maximum dichloroethene concentration is in the northeastern sample and is above comparison values (Table 11). The Navy detected lead (4-5 ppb) in surface water near Area 5 during the Current Situation Report (2) in 1987. Five metals were above comparison values. ATSDR could not determine any trends from the few sample points. Unspeciated chromium is listed, because it was detected above comparison values in groundwater.

Table 11. Contaminant Concentrations at Operable Unit 1

OU, Area	Contaminant	Min&Max Level for Each Contaminant	Reference AII-6/90, RI-7/91	Comparison Value, ppb	Source
On-Site Surface Water, ppb
OU1, 5	1,1-Dichloroethene	ND-4.9 ppb	RI/FS	0.058	CREG
OU1, 6	Antimony	ND-39.2 ppb	RI/FS	3	LTHA
	Arsenic	ND-15.2 ppb	RI/FS	11	RMEG
	Total chromium	ND-83.1 ppb	RI/FS	100	LTHA
	Lead	ND-33.5 ppb	RI/FS	None
	Nickel	ND-223 ppb	RI/FS	100	LTHA
	Vanadium	ND-205 ppb	RI/FS	20	LTHA
On-Site Groundwater - Monitoring wells, ppb
OU1, 5 Shallow Aquifer	1,1-Dichloroethene	ND-0.46	RI/FS	0.058	CREG
	Arsenic	ND-310B	IA, RI	11	RMEG
	Total Chromium	ND-36J	IA, RI	100	LTHA
	Lead	ND-29.9	IA, RI	None
	Manganese	ND-35,147	RI	3500	RMEG
	Nickel	ND-120	IA, RI	100	LTHA
	Nitrate	1100-13,000	IAS, IAS	10,000	MCLG
	Vanadium	ND-246	RI	20	LTHA
	Zinc	ND-2410	IA, RI	2100	LTHA

OU1 Area 6 unfiltered surface water samples were taken from a wetland in the central part of the area and from an ephemeral stream that flows from the wetland in Area 6, north to the wetland north of Ault Field Road. The maximum concentrations for arsenic, chromium, lead, and nickel were from a stream sample in the northeast corner of Area 6.

OU1 Groundwater - Monitoring Wells

Area 5

The Navy has not identified any groundwater contaminant plumes in Area 5. No contaminants were confirmed in Area 5 groundwater from three existing monitoring wells installed during the Accelerated Initial Investigation (29). During RI Phase I, the Navy sampled shallow aquifer groundwater at three existing wells once during the wet season and once during the dry season. They detected arsenic, chromium, manganese, nickel, vanadium, and zinc above comparison values (Table 11). The concentration of nitrate was above comparison values. VOC concentrations were below comparison values in a monitoring well in the north part of Area 5. No SVOCs, chlorinated pesticides, PCBs, organophosphorus pesticides, or chlorinated herbicides were detected (28). Groundwater under Area 5 appears to flow toward the northwest (6). Twelve groundwater samples were collected during the RI and analyzed for fluoride, nitrate, and sulfate.

Area 6

During RI Phase I at Area 6, the Navy sampled groundwater in 14 new monitoring wells and 15 existing wells, and six existing monitoring wells at the Oak Harbor Landfill, once during the wet season and once during the dry season (28). No SVOCs, pesticides, PCBs, organophosphate pesticides, or chlorinated herbicides were confirmed in groundwater in Area 6 during the Accelerated Initial Investigation (AII) in 1989 and Interim Action (IA) in 1990. Therefore, RI Phase II groundwater monitoring samples were analyzed for only VOCs and inorganics, except two wells near the hazardous waste storage area and two wells in southeastern Area 6, which were tested for VOCs, inorganics, SVOCs, pesticides, PCBs, organophosphate pesticides, and chlorinated herbicides (28).

Area 6 - Shallow Aquifer. The highest VOC concentrations were in the upper part of the shallow aquifer (Table 12). The maximum concentrations of 1,1,1-trichloroethane, trichloroethylene, 1,1-dichloroethene, total 1,2-dichloroethene, 1,1-dichloroethane, and carbon tetrachloride were from wells in or near the former hazardous waste storage area (6). Pesticides were detected below comparison values in wells in the south part of Area 6 and west central part of Area 6, respectively. The pesticide detections were isolated; the Navy presumed that they were a result of weed control activities at NAS (28).

Table 12. Contaminant Concentrations in On-site Groundwater Monitoring Wells, Operable Unit 1, Area 6

CONTAMINANT (reported as ppb)	Shallow Aquifer	Intermediate Aquifer	Deep Aquifer	Reference	Comparison Value, ppb	Source
1,1,1-trichloroethane	ND-32,000	ND-5J	ND-130	AII, IA, RI	200	LTHA
trichloroethylene	ND-1800D	ND-1.7	ND-167	AII, IA, RI	3.2	CREG
1,1-dichloroethylene	ND-1900D	ND	ND-23	AII, IA, RI	90	EMEG
1,2-dichloroethylene	ND-630D	ND	ND-60J	AII, IA, RI	100	LTHA (trans-)
Carbon tetrachloride	ND-4400	ND	ND	AII, IA, RI	0.27	CREG
Methylene chloride	ND-26,000E	ND-17J	ND-12B	AII, IA, RI	4.7	CREG
Vinyl chloride	ND-53.5	ND	ND	AII, IA, RI	0.7	EMEG
Antimony	18B	ND-71B	ND	AII, IA, RI/FS	3	LTHA
Arsenic	ND-25.2	ND-73	9.0B-70	AII, IA, RI	11	RMEG
Beryllium	ND	1.1	ND	AII, IA, RI	0.008	CREG
Cadmium	ND-9.8	ND	ND-7J	AII, IA, RI	7	EMEG
Total Chromium	ND-1180	ND-6.3BJ	ND-20J	IAS, CSR, AII, IA, RI	100	LTHA (CrVI)
Lead	ND-480	ND-114J	6.5-126J	IAS, CSR, AII, IA, RI	None
Mercury	ND-2.8J	ND	ND-0.31	AII, IA, RI	2	LTHA
Nickel	ND-756BJ	ND-9.8BJ	ND-18	AII, IA, RI	100	LTHA
Nitrate	30-8400	ND	ND	IAS, IA	10,000	MCLG
Vanadium	ND-148	ND	ND-18.2B	AII, IA, RI	20	LTHA
Zinc	ND-4310J	192-2210J	ND-7507	AII, IA, RI	2100	LTHA

J - Contaminant was positively identified; estimated concentration
B - Metals: Contaminant detected at less than contract required detection limit, but greater than the instrument detection limit
B - Organics: Contaminant detected in associated laboratory blank
D - Secondary dilution
ND - Not detected

The Navy has identified five VOC plumes in the shallow aquifer at Area 6; 1,1,1-trichloroethane (TCA), trichloroethylene (TCE), 1,1-dichloroethene, 1,2-dichloroethene, and vinyl chloride (6). The Navy detected the highest concentration of TCA at 32,000 ppb during the Interim Action in 1990; they detected TCA during the 1991 RI Phase II at 12,000 ppb in the same well. They detected 0.70 ppb TCA in a well at the western edge of the plume and 310 ppb TCA at the southern edge of the plume. The highest concentrations of the TCA, TCE, 1,1-dichloroethene, and 1,2-dichloroethene plumes are near the former hazardous waste storage area. The TCA, TCE, and 1,1-dichloroethene plumes appear to extend off site to the southwest about 250 feet from the western border of Area 6 and NAS and south to the border of Area 6 and Oak Harbor landfills (Appendix A, Figure 15). The 1,2-dichloroethene plume does not extend as far south as the TCA, TCE, and 1,1-dichloroethene plumes. The highest detected concentration of vinyl chloride was in a monitoring well near the southwestern corner of Area 6, and near the southwestern corner of the current active Navy landfill operation. The source of vinyl chloride is near the monitoring well or is the active landfill trenches (6). Vinyl chloride (2.58 ppb) was detected in a monitoring well near the southeast corner of Area 6, about 300 feet from the Auld Holland Inn.

The vertical extent of contamination in the shallow aquifer is shown by detections of TCA at the bottom of the aquifer of 1150 ppb near the former hazardous waste storage area to 61 ppb at the bottom of the southern edge of the plume. Concentrations of TCA at the southwestern border of Area 6 have increased from 920 ppb to 3900 ppb from 1989 to 1991. Concentrations at the southeastern edge of the plume have increased from 5 to 11 ppb from 1990 to 1991 (6).

Unfiltered samples in the shallow aquifer were analyzed for inorganics. The highest arsenic level is from a well in the hazardous waste storage area. Cadmium was generally detected in wells and to the west of Area 6, and the elevated levels in the RI Phase II were not detected in Phase I (6). A well at the northeast border of Area 6 and NAS consistently had the highest chromium readings (403, 387, and 1180 ppb). High lead levels were detected during the 1991 RI in the shallow aquifer in the southern part of Area 6 (63.7-121 ppb) and southwest of Area 6 (58.75-87.3 ppb) (6). The maximum lead level detected during a Navy study in March 1982 came from a well at the southeastern edge of Area 6 (29).

During the Initial Investigation at Area 6, the highest manganese levels came from wells in the hazardous waste storage area, but manganese levels were much lower during later sampling and the RI Phase II. Those levels of manganese were also near the active landfill area. Manganese was not detected in filtered samples from wells where manganese was previously detected; therefore, the Navy concluded manganese concentrations are due to suspended particles not dissolved in shallow groundwater (6). Manganese levels were below comparison values. The Navy presumes that other detections of heavy metals are a result of suspended particles in the groundwater (6).

Unfiltered mercury was detected twice in the shallow aquifer during the RI Phase I, but was not detected in other sampling. The maximum mercury level came from a well in the central part of Area 6. The highest nickel concentration came from a well in the northwest corner of Area 6 and a well in the hazardous waste storage area. Nickel was detected in groundwater on the east side of Area 6 and in two wells in the hazardous waste storage area. Vanadium maximum concentrations came from a well in the hazardous waste storage area. The highest zinc concentrations came from wells around the active landfill area in the southern part of Area 6. The Navy detected nitrate during the IAS and IA investigation at levels below comparison values. Nitrate values are in the table because levels are above comparison values in Area 5.

Area 6 - Intermediate Aquifer. SVOCs, pesticides, chlorinated herbicides, and PCBs were not detected in the intermediate aquifer. VOCs were detected from 0.99-6 ppb; TCE was detected in a well in the former hazardous waste storage area in all three sampling phases (Table 12). During the OU1 Rapid Response and RI Phase II, chloroform (6 and 4 ppb) was detected in an off-site monitoring well northwest of the Area 6 former hazardous waste storage area. The Navy reported those concentrations were estimated and below the detection limit.

During both RI phases, vinyl chloride (3.35 and 0.72 ppb) was detected in the intermediate aquifer in an off-site monitoring well west of the former hazardous waste storage area near Goldie Road. The Navy states the well is upgradient of the former hazardous waste storage area (6). Methylene chloride was detected six times at estimated concentrations from 2-10 ppb. The Navy said that the methylene chloride was a laboratory contaminant because it was not consistently detected in all samples and was not detected at the same level in later samples (6). The Navy considered inorganic analyte detections to be inconsistent and random, except arsenic and lead. Detections of arsenic and lead were widespread during the RI Phase II (6). Unfiltered arsenic at 73.2 ppb was detected in an off-site monitoring well southwest of the former hazardous waste storage area near Goldie Road; the Navy believes the source to be upgradient and off site (6). Lead was detected six times from 16.5-114 ppb. Manganese was detected at a maximum of 1003 ppb. The highest lead and manganese concentrations came from a monitoring well in the southwest corner of Area 6.

Area 6 - Deep Aquifer. VOCs were detected in the deep aquifer in a well in the former hazardous waste storage area (Table 12). A TV camera survey showed two well pipe joints in the shallow aquifer (80 and 100 feet) were leaking, forming a path for contaminated water from the shallow aquifer to cross-contaminate the deep aquifer. Steps to remedy this situation currently are in progress (6). Vinyl chloride and PCBs were not detected in the deep aquifer (24). Four VOCs detected in the shallow aquifer were detected in the deep aquifer at levels less than 1 ppb; TCE and 1,1-dichloroethene detections were from deep monitoring wells along the eastern and southern boundaries of Area 6 and NAS. Methylene chloride was detected four times at concentrations from 6-12 ppb. The Navy said that the methylene chloride was a laboratory contaminant because it was not detected consistently in all samples and was not detected at the same level in later samples (6). More recent sampling results and review of data validation has clarified the quality assurance/quality control questions and the Final RI report (June 1993) provides additional information. Bis(2-ethylhexyl)phthalate (BEHP) was detected in the deep aquifer during the Initial Investigation (II) at 2-110 ppb, and in only one sample (40 ppb) during the IA. The Navy does not consider SVOCs to be of concern in the deep aquifer (6); however, future sampling data will help to establish if the BEHP detections are laboratory artifacts or groundwater contaminants. Isolated detections of 2-methyl-4-chlorophenoxyacetic acid (MCPA) (5.3 ppb) and 2,4,5-TP (0.16 ppb) below comparison values came from deep aquifer monitoring wells along the eastern and southern border of Area 6 and NAS (6). The detection of those pesticides is puzzling, since the Navy says they are applied for weed control on the surface. ATSDR believes these detections may be due to sampling or analysis errors, documentation error, faulty well construction that allowed surface contamination to reach the deep aquifer, or surface contaminants have infiltrated through the soil to the deep aquifer.

The highest unfiltered arsenic detections in the deep aquifer were from wells along the eastern border of Area 6; the Navy believes the source is off site (6). A single lead detection (93 ppb) came from a well along the eastern border of Area 6; cadmium (3-7 ppb) and chromium (20 ppb) were also detected in that well. Two mercury (0.22 and 0.31 ppb) detections exceeded the MCL, and came from a deep aquifer monitoring well at the northeast border of Area 6.

OU1 Ambient Air

Soil surface emission flux monitoring for VOCs was done at 36 locations during the RI at OU1, Area 6 both on and off site to the west. The emission flux isolation chamber measures VOC emissions from the soil over a small surface area. The Navy used soil gas survey results to locate emission flux sample stations (6). The Navy conducted the sampling in August 1991. Thirty-nine VOCs or metals were analyzed for in each sample. TCA was present throughout the measured area and was being emitted at concentrations up to 120 ppb (6). TCE, 1,1-dichloroethene, and toluene were detected less frequently at concentrations from 1-10 ppb. Benzene (1.7 ppb) and 1,1-dichloroethene (1.9 ppb) emission values were above comparison values for air. The Navy detected those concentrations about 400 feet northwest of the former hazardous waste storage area. The results were consistent with soil gas, soil, and groundwater sampling results (6).

The Navy conducted ambient air measurements and total suspended particulate and toxic metals sampling at Area 6. Sample locations were upwind and downwind of the former hazardous waste storage and off site to the west in August 1991 at five locations. Wind measurements taken during the sampling showed prevailing winds from the north-northwest and south-southeast (6). Only 1,1,1-trichloroethane (0.68-4.4 ppb), toluene (0.70-65 ppb), and Freon 12 (0.89-1.6 ppb) were consistently detected during RI sampling. Suspended particulate sampling RI results at Area 6 detected lead (0.076 micrograms per cubic meter [µg/m³]) and copper (1.0 µg/m³). The RI indicates that lead was probably from nearby automobile traffic, and the copper was from the motor armature of the sampling device (6). Freon 12 detection was infrequent. The RI considered Freon widespread in the environment and of little significance (6).

Operable Unit 2

OU2 (Appendix A, Figure 4) consists of Area 2 (Western Highlands Landfill), Area 3 (1969-1970 Landfill), Area 4 (Walker Barn Storage Area), Area 14 (Pesticide Rinsate Disposal Area), and Area 29 (Clover Valley Road Fire School). Soil, sediment, surface water, and groundwater analyses included metals and cyanide, VOCs, SVOCs, pesticides, PCBs, organophosphorus pesticides, and chlorinated herbicides. The Navy conducted soil gas and ambient air sampling at Area 2 and Area 3 during the RI sampling in 1992; however, data were not available when this public health assessment was being written. Area 4 receives airborne contamination from the existing fire school, which is about 300 feet southwest of Area 4 (30).

OU2 Surface Soil

At Area 2, Western Highland Landfill, and Area 3, 1969-1970 Landfill, low levels of pesticides were detected in the wetland to the east of Area 2 and southwest of Area 3 (Appendix A, Figure 4). Pesticides above comparison values or with no comparison value were detected in a single sample about 400 feet south and upgradient of Area 3. Soil samples were not taken from the suspected landfill areas.

In OU2 Area 4, Walker Barn Storage, a grid system was established across the area, and composite samples of surface soil were collected to form twenty-three samples for analysis during the Current Situation Report (CSR) in 1987. All composite samples had detectable levels of PCBs. The CSR monitoring data came from composite samples; the CSR says that a single sample could have PCBs about eight times the level in the composite samples (2). The PCB contamination of soils was confirmed in 1992 at levels significantly higher than detected in the CSR (Table 13) (30).

At OU2 Area 14, the Pesticide Rinsate Disposal Area, a grid system was established. During the 1987 CSR, 100 soil samples (0-6 inch depth) were collected and composited, forming 22 samples for analysis. Composited soil samples were collected from within and around the defoliated area, but analytical results for the samples showed no detectable levels of organochlorine pesticides, chlorophenoxy herbicides, or PCBs (the detection limits used were not specified). RI sampling in 1992 detected pesticide levels above comparison values listed in Table 13. Bromacil (1.3 mg/kg), prometon (1.3 mg/kg), and lindane (0.0022 mg/kg) were also detected (31), but have no comparison values for soil.

OU2 Area 29, Clover Valley Road Fire School, is unpaved except a concrete burn pad. During the CSR, soil samples were collected at eight Area 29 locations around the perimeter of the burn pad and composited into five samples for analysis. Two other background samples were collected northwest of the burn pad. The samples were analyzed for total organic halogens, lead, PCBs, and polynuclear aromatic hydrocarbons (PAHs). The lead concentrations probably resulted from combustion of leaded fuels (Table 13). The PAH background level was 9 mg/kg, which is above comparison values. RI/FS sampling confirms the lead and PAH contamination. Twelve samples were taken from around the burn pad and to the northeast and east. Area 29 contaminants, lead and PAHs, were highest to the northeast of the burn pad, which conforms to the prevailing winter wind direction from the southwest. PAH contamination below background values, but above comparison values were detected east of the area in a drainage pond. Detection limits for PCBs varied from 0.03 mg/kg to 1.5 mg/kg due to unspecified chemical interferences (20).

Table 13. Contaminant Concentrations at Operable Unit 2

OU, Area	Contaminant	Min&Max Level for Each Contaminant	Reference	Comparison Value	Source
On-Site Surface Soil, mg/kg				mg/kg
OU2, 2	Silvex (2,4,5-TP)	16	RI/FS	16	RMEG
OU2, 4	PCB	<0.05-8.7, 3/87.	CSR	0.091	CREG
	PCB	1.2-2600	RI/FS	0.091	CREG
OU2, 14	TCDD (total) (tetrachlorodibenzo-p-dioxin)	0.0051	RI/FS	0.0007	EMEG
	HpCDD (total) (hexachlorodibenzo-p-dioxin)	0.0091-0.025	RI/FS	0.00011	CREG (HxCDD)
	HxCDD (total) (hexachlorodibenzo-p-dioxin)	0.0051-0.0052	RI/FS	0.00011	CREG (HxCDD)
	Heptachlor epoxide	0.089	RI/FS	0.077	CREG
OU2, 29	Lead	7.6-250, 1987.	CSR	None
	Carc. PAHs	0.13-12.8, 1987	CSR	0.12	CREG (BaP)
	Lead	65.7-206	RI/FS	None
	Carc. PAH	3.4-35.6	RI/FS	0.12	CREG (BaP)
On-Site Sediment, mg/kg				mg/kg
OU2, 2	Lead	48-805	RI/FS	None
On-Site Subsurface Soil, mg/kg				mg/kg
OU2, 4	PCB	0.78-37	RI/FS, 1'-15'	0.091	CREG
OU2, 29	Pentachlorophenol	6.2-19	RI/FS, 3'	5.8	CREG
	Carc. PAH	0.71-87	RI/FS, 1'	0.12	CREG (BaP)
	Lead	76.3	RI/FS, 1'	None
On-Site Surface Water, ppb				ppb
OU2, 2	Total chromium	<1-75 ppb, 1987	CSR	100	LTHA (CrVI)
	Lead	<1-35 ppb	RI/FS	None
	benzofluoranthene	0.046-0.3 ppb	RI/FS	0.006	CREG (BaP)
OU2, 29	Nickel	140 ppb	RI/FS	100	LTHA
	Manganese	7090 ppb	RI/FS	3500	RMEG
	benzofluoranthene	0.086-0.092 ppb	RI/FS	0.006	CREG (BaP)

OU2 Sediment

The maximum lead value for the eight sediment samples in OU2, Area 2, was detected in wetland east of Area 2, near the boundary of the southern part of Area 2 (Table 13). Pesticides were detected at levels below comparison values in 60% of the samples. In Area 14, pesticides were detected in all four samples from a drainage ditch that flows through the area. The pesticides were detected upstream (northwest) and were highest at and immediately downstream of the area under investigation. A sediment sample downstream (south) had a reduced level of pesticide (30).

OU2 Subsurface Soil

At Area 4, PCB concentrations above comparison values were detected to a depth of 15 feet, and levels were much lower in subsurface soils compared to surface soils. At Area 29, pentachlorophenol and PAHs above comparison values were detected at depths of 1 to 30 feet during the RI sampling in 1992 (Table 13) The maximum pentachlorophenol was detected at a 3-foot depth during drilling of a monitoring well in a former waste liquid surface impoundment across the Rocky Point road and northeast of Area 29 (8); the level was 17,000 mg/kg at a 1-foot depth. Metals, VOCs, and PAHs were detected in soil samples taken when drilling monitoring wells.

OU2 Surface Water

At OU2, three surface water samples were collected and analyzed during the Current Situation Report in 1987 (Table 13). Two samples were collected and analyzed from just east of Area 2 in the wetland area and the third surface water sample was taken from an ephemeral stream draining the wetland to the east (just south of Area 3). The Navy conducted sampling once during the wet season (March) and once during the dry season (July). The cadmium concentration reported in the Preliminary Public Health Assessment and Current Situation Report of 61 ppb at Area 2 was corrected to 0.6 ppb based on analytical confirmation of a duplicate sample with the analytical laboratory (20). The 0.6 ppb chromium value is below comparison values. The unspeciated chromium (55 ppb, dry season) was believed to come from landfill leachate contaminating the surface water (20). During the RI, lead was detected in a sample taken during the dry season. The PAH values were detected near the north end of Area 2; the current fire school is also near the north end of Area 2.

In Area 29, PAHs were detected above comparison values in a drainage ditch near the northern end of the area. Flow in the ditch is to the east. No PAHs were detected in the surface water sample taken near the concrete burn pad. Manganese and nickel above comparison values, and arsenic and chromium below comparison values were detected in the sample near the burn pad.

OU2 Groundwater - Monitoring Wells

Eleven groundwater monitoring wells were installed around the perimeter of Area 2, and samples were collected in the dry season during the Current Situation Report in 1987. Three monitoring wells were installed at Area 3. At OU2, a groundwater divide may be present in the main aquifer beneath these Areas 2 and 3, which causes groundwater under Area 2 to flow westward toward the Strait of Juan De Fuca, and groundwater under the wetland and Area 3 to flow east. There are also areas of perched groundwater under both areas that may be recharged by surface water from the wetlands or may seep into the wetlands thereby creating a conduit for contamination of two media. Samples were analyzed for cadmium, chromium, and lead. The Navy conducted sampling once during the wet season (March) and once during the dry season (July). The sampled water in several wells was a greenish color (8). Water in the perched zone also showed iron concentrations up to several times higher than in the main aquifer, and an oily substance was observed in several wells (Table 14). Cadmium was detected at levels above comparison values in a shallow well near the center of Area 2. Wells sampled during the RI detected arsenic and chromium at levels above comparison values. Preliminary RI data show that high metal levels in groundwater seem to come from wells around the periphery of Areas 2 and 3 and near Area 3; additional data are needed to find possible causes of this pattern.

Three groundwater monitoring wells were installed on OU2 Area 14. Samples were analyzed for organochlorine pesticides and chlorophenoxy herbicides during the CSR, but no compounds were detected at the detection limits (which were not listed) (2). Data from the subsequent RI/FS showed pesticides, VOCs, and SVOCs (Table 14). The highest concentrations of pesticides were detected in a monitoring well near the north end of the area of dead vegetation in Area 14. Pesticide concentrations were also elevated in a monitoring well in the dry well. CN (chloracetophenone), which is an ingredient in chemical Mace, and low levels of chemicals associated with fire suppression foam were detected. ATSDR does not know the source of those chemicals. CN and 1,2,4-trimethylbenzene do not have comparison values. The CN was detected in a well east and upgradient of Area 14 (30).

Four groundwater monitoring wells were installed as part of the CSR at Area 29. The CSR stated that analytical results for petroleum hydrocarbons and lead (1-7 ppb) were at or below background levels. Data from the RI/FS showed several metals and pentachlorophenol above comparison values in Area 29 groundwater (Table 14). Standing water covered most of the area at the time of the RI sampling in 1992; indicating the low permeability of the soil (30). Surface water drains to the east. Discontinuous perched water in all three wells drilled occurred at varying depths (30). The monitoring well north of the burn pad is in a perched aquifer (2), and samples from the well had the maximum chromium, manganese, and nickel listed in Table 14. High lead and arsenic was detected in a bedrock well that was dry during the CSR sampling in 1987, which suggests low permeability (2). The well is north of the burn pad.

Table 14. Contaminant Concentrations at Operable Unit 2

OU, Area	Contaminant	Min&Max Level for Each Contaminant	Reference	Comparison Value	Source
On-Site Groundwater - Monitoring wells, ppb				ppb
OU2, 2	Cadmium	ND-40 (6/87)	CSR	7	EMEG
	Arsenic	11-31	RI/FS(a)	11	RMEG
	Total chromium	44-199	RI/FS	100	LTHA (CrVI)
	Lead	38-46	RI/FS	None
OU2, 3	Arsenic	59	RI/FS	11	RMEG
	Total chromium	30-86	RI/FS	100	LTHA (CrVI)
	Lead	1-75	CSR, RI/FS	None
	Nickel	156	RI/FS	100	LTHA
	Vinyl Chloride	22	RI/FS	0.7	EMEG
OU2, 4	Arsenic	12	RI/FS	11	RMEG
	Total chromium	181	RI/FS	100	LTHA (CrVI)
	Lead	33.6	RI/FS	None
	Zinc	3090	RI/FS	2100	LTHA
OU2, 14	Silvex	20	RI/FS	20	LTHA
	2,4-D	260	RI/FS	70	LTHA
	Prometon	570	RI/FS	100	LTHA
	2,4-Dichlorophenol	2800	RI/FS	20	LTHA
	Naphthalene	1000	RI/FS	20	LTHA
	Benzene	1.3	RI/FS	1.2	CREG
	1,2,4-trimethylbenzene	150	RI/FS	None
	CN (a-chloroacetophenone)	10	RI/FS	None
OU2, 29	Pentachlorophenol	1.1-28	RI/FS	0.29	CREG
	Arsenic	47-53.2	RI/FS	11	RMEG
	Total Chromium	50-941	RI/FS	100	LTHA
	Lead	42.6	RI/FS	None
	Manganese	760-9720	RI/FS	3500	RMEG
	Nickel	105-1260	RI/FS	100	LTHA

OU2 Ambient Air

There are no data available on the ambient air contamination at OU2 (9).

Operable Unit 3

OU3 consists of Area 16, the Runway Ditches, and Area 31, the Runway Fire School (Appendix A, Figure 5). This operable unit was formed because Areas 16 and 31 are next to each other and contaminants in Area 31 flow into Area 16. As part of the CSR, soil and sediment samples were collected in March 1987 at nine locations along ditches in Area 16. Two arresting gear on runway 31-13 in Area 16 have tanks that collect ethylene glycol from the arresting gear. If the amount of glycol exceeds the capacity of the tanks, the excess is piped to the nearby grasslands. Sampling and analysis of the grassland soils is scheduled for the fall of 1992 (7). Soil and sediment analyses included metals, PCBs, and PAHs. Groundwater samples were analyzed for lead. Additional samples taken during the RI will be analyzed for marine sediments, lagoon fish and shellfish, and marine shellfish. Pesticide sampling is not scheduled for Area 31 (32). Lead concentrations are shown in the table of contaminants because ATSDR has not developed ingestion and dermal contact comparison values for lead that is detected in soil or sediment.

OU3 Surface Soil

At Area 16, the Runway Ditches, four soil samples from the top three inches of soil from the ditch banks were collected for compositing into two samples for analysis. Four soil samples were also collected from a common dredge spoil disposal area for analysis. Samples were composited at each location using equal weights of each sample. The top three inches of soil were sampled. PAHs above comparison values (Table 15) and arsenic (6.5-170 mg/kg) were detected (2). The high arsenic came from a sample near the boundary of NAS, where the runway ditches flow off site Petroleum hydrocarbons were detected in 40% of the soil samples at levels as high as 30,000 mg/kg (3% by weight) (2), which was detected in a sample next to the flight line and near the hanger area and Area 19, Fuel Truck Depot. The maximum lead levels in soil and sediment were also detected at that location.

Soil and standing water at Area 31, Runway Fire School, had an oily sheen during the IAS and CSR investigations. Soil samples were collected in March 1987 from 16 locations around the burn pad and near the lowland marshy area during the CSR. Analysis was done on composite samples. Samples collected from around the burn pit were composited into four samples for analysis. Samples collected along a drainage between the burnpit and the marshy area were composited, and samples collected in the marshy area were composited. Two samples collected in an area of dead vegetation were composited. The top three inches of soil were sampled at each location. Analysis of PCB combustion products was not done as part of the CSR. PAHs and PCBs were detected above comparison values (Table 15). The highest PAHs were detected in samples taken around the burn pad, to the south and southeast. PAHs were also detected downstream of Area 31 in the marsh that drains to the runway ditches; the highest PCB detection was also in the marsh. Lower levels of PCBs were detected around the burn pad. The lower levels could indicate that actual PCB concentrations were diluted by the compositing of samples, or that PCB contaminated soils were washed downstream into the marsh.

Table 15. Contaminant Concentrations at Operable Unit 3

OU, Area	Contaminant	Min&Max Level for Each Contaminant	Reference	Comparison Value	Source
On-Site Surface Soil, mg/kg				mg/kg
OU3, 16	Lead	2.9-310 mg/kg 3/87	CSR	None
	Carc. PAH	0.19-1.72 mg/kg	CSR	0.12	CREG (BaP)
OU3, 31	Lead	62-310 mg/kg, 3/87	CSR	None
	Carc. PAH	ND-2.15 mg/kg	CSR	0.12	CREG (BaP)
	PCB	0.10-4.14 mg/kg 3/87	CSR	0.091	CREG
On-Site Sediment, mg/kg				mg/kg
OU3, 16	Lead	2.8-1000 mg/kg 3/87	CSR	None
	Carc. PAH	0.04-5.98 mg/kg	CSR	0.12	CREG (BaP)
Carc. PAH (carcinogenic PAH) - benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, ideno(1,2,3-cd)pyrene, dibenz(a,h)anthracene, benzo(g,h,i)perylene

OU3 Sediment

Sediment samples for OU3, Area 16, the Runway Ditches, were taken in March 1987 from nine locations. At each location, six sediment samples were collected from the bottom of the ditches for compositing into two samples for analysis. Concentrations of PAHs, heavy metals, and petroleum hydrocarbons above background concentrations were detected in ditch sediments (Table 15). Petroleum hydrocarbons as high as 30,000 mg/kg were detected in almost all ditch sediments and soils. A fuel scan during the CSR showed that the primary fuel contaminant was diesel #2. All eleven analyzed metals were detected at that sample station where the high petroleum hydrocarbon was detected. Unspeciated chromium (25-88 mg/kg) was detected below comparison values, and the maximum chromium was detected near the flight line station where the sample with the maximum petroleum hydrocarbon was taken. Arsenic was detected at levels below comparison values; the sample showing 52 mg/kg came from the central area of the runways. Lead was detected; however, there is no comparison value available for lead in soil. The location of the sample with the highest lead level was discussed in the soil section. The CSR used background concentrations for arsenic and lead of 4.7 mg/kg and 1.5 mg/kg, respectively (2). PAHs were detected above comparison values; the maximum PAH concentration was detected near the flight line station where the sample with the maximum petroleum hydrocarbon concentration was detected.

OU3 Surface Water

Surface water testing was not performed during the Initial Assessment Study or Current Situation Report at OU3; however, both reports mention standing water at Areas 16 and 31 having an oily sheen. This observation was confirmed during the ATSDR site visit.

OU3 Groundwater - Monitoring Wells

Groundwater was not sampled at Area 16 during the Current Situation Report (CSR). In April 1987, four groundwater monitoring wells were installed at Area 31, as part of the CSR. Well locations were selected to provide data at the former burn pad and nearby surface drainages. One well was in a perched water zone above the local water table. The other three wells are in the water table aquifer. Groundwater is 12 to 20 feet deep, and groundwater flow is believed to be south-southwest. The perched water zone is at a depth of five feet (2). Low levels of lead (ND-2 ppb) and petroleum hydrocarbons were detected.

Operable Unit 4

OU4 consists of the Seaplane Base areas (Appendix A, Figure 6), Area 39 (Auto Repair and Paint Shop), Area 41 (Buildings 25 and 26 Disposal Area), Area 44 (Seaplane Base Nose Hangar), Area 48 (Seaplane Base Salvage Yard), and Area 49 (Seaplane Base Landfill). Groundwater is not in use at Seaplane Base; however, Base Well No. 5 is in the family housing area. Soil, sediment, surface water, and groundwater sampling will be conducted during the RI and will include analysis for metals and cyanide, VOCs, SVOCs, pesticides, PCBs, organophosphorus pesticides, and chlorinated herbicides. Pesticide and PCB sampling is not scheduled at Area 39 or Area 44. Sampling of other Seaplane Base areas was performed during the HWES.

OU4 Soil

At OU4 Areas 39, 41, 44, and 48/49, VOCs, PAHs, SVOCs, and metals were detected above comparison values (Table 16). Pesticides and PCBs were detected at Areas 41 and 48/49 above comparison values. Organophosphorus or chlorinated pesticides were not detected. Composite samples were taken at 0-2 inch depths and 2-15 inch depths (14). Data tables in the Navy's 1992 Initial Screening of Contaminants (ISC) for OU4 did not differentiate detected compounds by sample depth or location. Contaminants above comparison values listed in Table 16 for soil are for unspecified depths. Lindane was detected at Area 41 (21 mg/kg) and Areas 48/49 (2.9-13 mg/kg), but has no comparison value for soil.

Table 16. Contaminant Concentrations at Operable Unit 4, Seaplane Base

OU, Area	Contaminant	Min&Max Level for Each Contaminant	Reference	Comparison Value	Source
On-Site Soil at unspecified depth, mg/kg				mg/kg
OU4, 39	Carc. PAH	276-6200 mg/kg	ISC, 2/92	0.12	CREG (BaP)
	n-Nitrosodiphenylamine	140J-490 mg/kg	ISC, 2/92	140	CREG
	Lead	2.9N-736 mg/kg	ISC, 2/92	None
41	Carc. PAH	124-815 mg/kg	ISC, 2/92	0.12	CREG (BaP)
	n-Nitrosodiphenylamine	84BJ-250J mg/kg	ISC, 2/92	140	CREG
	4,4-DDT	6.1P-380 mg/kg	ISC, 2/92	2.1	CREG
	4,4-DDD	1.6JP-13P mg/kg	ISC, 2/92	2.9	CREG
	4,4-DDE	0.57P-48 mg/kg	ISC, 2/92	2.1	CREG
	PCB	26JP-780P mg/kg	ISC, 2/92	0.091	CREG
	Dieldrin	9.2P mg/kg	ISC, 2/92	0.044	CREG
	Heptachlor epoxide	4.5P mg/kg	ISC, 2/92	0.077	CREG
	Lead	1.8-298 mg/kg	ISC, 2/92	None
OU4, 44	Methylnaphthalene	1300-6900E mg/kg	ISC, 2/92	None
	Naphthalene	560-79,000E mg/kg	ISC, 2/92	None
	Carc. PAH	1188 mg/kg	ISC, 2/92	0.12	CREG (BaP)
	n-Nitrosodiphenylamine	600B-910B mg/kg	ISC, 2/92	140	CREG
	Pentachlorophenol	44-200J mg/kg	ISC, 2/92	5.8	CREG
	Lead	2.9-4400N mg/kg	ISC, 2/92	None
	Mercury	0.02-3.3 mg/kg	ISC, 2/92	None
OU4, 48/49	Benzene	180 mg/kg	ISC, 2/92	24	CREG
	Carc. PAH	96-6200 mg/kg	ISC, 2/92	0.12	CREG
	n-Nitrosodiphenylamine	92BJ-300B mg/kg	ISC, 2/92	140	CREG
	4,4-DDT	0.46J-38 mg/kg	ISC, 2/92	2.1	CREG
	4,4-DDD	0.42JP-5.9P mg/kg	ISC, 2/92	2.9	CREG
	4,4-DDE	0.24J-26.4 mg/kg	ISC, 2/92	2.1	CREG
	PCB	40P-220P mg/kg	ISC, 2/92	0.091	CREG
	Dieldrin	0.31JP mg/kg	ISC, 2/92	0.044	CREG
	Heptachlor epoxide	0.46JP-1.5JP mg/kg	ISC, 2/92	0.077	CREG
	gamma-Chlordane	0.48JP-2.2P mg/kg	ISC, 2/92	0.54	CREG
	Lead	154N mg/kg	ISC, 2/92	None
Data from the Initial Screening of Contaminants and Conceptual Site Models Technical Memorandum, Operable Unit 4 (ISC) are not validated.

Table 17. Contaminant Concentrations at Operable Unit 4, Seaplane Base

OU, Area	Contaminant	Min&Max Level for Each Contaminant	Reference and Max. Area	Comparison Value	Source
On-Site Sediment, mg/kg				mg/kg
OU4, 41	Carc. PAH	84J-115J mg/kg	ISC	0.12	CREG (BaP)
	Lead	2.4-151 mg/kg	ISC	None
	Mercury	0.01-0.24 mg/kg	ISC	None	None
OU4, 44	Lead	2.9 mg/kg	ISC	None
On-Site Groundwater - Monitoring wells, ppb				ppb
OU4, Unknown	Vinyl chloride	2J-10	ISC	0.7	EMEG
35, 36	Benzene	0.011-980E	HWES, 36	1.2	CREG
	bis(2-ethylhexyl)phthalate	2-6	HWES, 36	2.5	CREG
	methylene chloride	7B-11	HWES, 35	4.7	CREG
	Antimony	16.6-44	HWES, 36	3	LTHA
	Arsenic	3.5-87.5	HWES, 35	11	RMEG
	Beryllium	0.10-5.3	HWES, 36	0.0081	CREG
	Cadmium	2.0-15.2	HWES, 35	7	EMEG
	Total Chromium	20.6-620	HWES, 36	200	RMEG(CrVI)
	Lead	4.0-5920	HWES, 35	None
	Manganese	1630-241,000	HWES, 36	70,000	RMEG
	Mercury	0.1-3.6	HWES, 35	2	LTHA
	Nickel	112-1030	HWES, 35	100	LTHA
	Thallium	0.1-3.6	HWES, 35	0.4	LTHA
	Vanadium	18.4-860	HWES, 36	20	LTHA
	Zinc	23.3-11,110	HWES, 36	2100	LTHA
Organic qualifiers B=Analyte also detected in blank samples E=Actual value greater than upper calibration range J=Reported concentration less than sample quantification limit P=Greater than 25% difference between the primary and confirmation gas chromatograph columns Inorganic qualifiers B=Reported concentration less than contract required detection limit but greater or equal to instrument detection limit E=Estimated because of interferences N=Spike sample recovery not within control limits

OU4 Soil Gas

Methylene chloride (16 ppm) was detected in one soil gas sample near Area 45, TCE Tank, at Seaplane Base during the HWES. The methylene chloride was detected in a sample from the opposite side of Building 14 from the suspected location of the TCE tank; additional sampling may be required to locate the tank. Low levels of VOCs (1-8 ppm) were detected at Area 35 and 36 fuel farms; heavy rains before and during the survey could have affected the sampling effort (33).

OU4 Sediment

At OU4, PAHs were detected in Area 41 above comparison values and Areas 48/49 marine sediments. Lead and mercury, which have no comparison values in sediment, were also detected in Area 41, 44, and 48/49 marine sediments (Table 17). Arsenic, cadmium, and chromium were detected below comparison values. Only summary data were provided in the ISC, so data trends could not be determined. The marine sediments were collected at 0-4 inch, 4-20 inch, and 20-36 inch depths; however, data tables did not differentiate detected compounds by depth or location (14).

OU4 Surface Water

During the RI for OU4, one surface water sample was collected from the wetland near Area 48/49; other sample sites were dry. The Initial Screening of Contaminants (ISC) only reported methylene chloride (3J ppb) and benzo(a)anthracene (5.5 ppb) data were available. Specific sampling sites were not given in the document.

OU4 Groundwater - Monitoring Wells

During the RI for OU4, VOC and metals were detected above comparison values at several Seaplane Base sites (Table 17). Most of the maximum detected contaminant levels were at Area 35, Fuel Farm 2, and Area 36, Fuel Farm 1. During the RI, vinyl chloride was detected in four monitoring wells. VOCs and SVOCs were detected, but location information was not given. Groundwater is not used at OU4.

Operable Unit 5

OU5 is a proposed OU that includes Area 1 (Beach Landfill) and Area 52 (Jet Engine Test Cell). Area 52 is next to Area 1 (Appendix A, Figure 7). Groundwater is not in use in OU5. Area 1 was investigated during the CSR and HWES. Area 52 was investigated in 1987, 1988, and 1989 as part of a Site Characterization Report (34). During the HWES, sandpoint monitoring wells, sediment, and surface water were sampled at Area 1. At Area 1, sediments were analyzed for VOCs, SVOCs, pesticides, PCBs, and metals during the CSR and HWES. Groundwater was analyzed at Area 52 for VOCs and SVOCs (34). Subsurface soils were sampled and analyzed for petroleum hydrocarbons, fuel hydrocarbons, VOCs, SVOCs, metals, pesticides, and PCBs.

OU5 Soil

The Navy did not sample surface soil (<3 inches) at OU5. Soil less than 1 foot was sampled during the Hazardous Waste Evaluation Study (HWES), and detected contaminants were below comparison values. Lead (14.1 mg/kg), vanadium (75.1 mg/kg), and zinc (80.5 mg/kg) do not have soil comparison values.

OU5 Sediment

The Navy sampled sediments at OU5 from a wetland in Area 1, Beach Landfill. The HWES detected several metals above comparison values as shown in Table 18. BEHP and PCBs were detected at levels several times higher than comparison values. Unspeciated chromium was detected at 21.7 mg/kg.

OU5 Subsurface Soil

The Navy conducted site characterizations of OU5 Area 52, the Jet Engine Test Cell in 1987, 1988, and 1989. Two soil borings, two test pits, and soil resistivity surveys were completed west of the existing test cell during a geotechnical study for the installation of a second test cell. Petroleum hydrocarbons were detected in test pits east-northeast of the existing test cell. Additional soil samples were collected at 2.5-foot deep intervals; samples to depths of 15 to 25 feet came from twelve hollow-stem auger borings. Soil samples to depths of 31 to 47 feet came from three cable tool borings. Total petroleum hydrocarbons (2100 mg/kg) and JP-5 (750 mg/kg) were detected (34). Cadmium (0.81-2.5 mg/kg) was detected in soil. The background cadmium concentration in soil was 0.3 mg/kg (34). Total petroleum hydrocarbons (2100 mg/kg) and JP-5 (750 mg/kg) were detected (34).

OU5 Surface Water

The Navy sampled a wetland area in OU5 Area 1 during the HWES. Several metals were detected, but only beryllium was above comparison values (Table 18). VOC and SVOC detections were not conclusive and may be a result of sampling or laboratory contamination (13).

OU5 Groundwater - Monitoring Wells

Groundwater is not used in OU5. During the HWES, the Navy installed and sampled five wells drilled on the downgradient western edge of the Area 1 landfill, along the Strait of Juan de Fuca (Appendix A, Figure 7). Bis(2-ethylhexyl)phthalate (BEHP) and methylene chloride were detected above comparison values (Table 19). The HWES report showed BEHP in four of five monitoring wells and methylene chloride detections in all five wells. The highest BEHP came from the well in the south central edge of the landfill. Ten heavy metals exceeded comparison values.

Table 18. Contaminant Concentrations at Operable Unit 5

OU, Area	Contaminant	Min&Max Level for Each Contaminant	Reference	Comparison Value	Source
On-Site Sediment, mg/kg				mg/kg
OU5, 1	Bis(2-ethylhexyl)phthalate	75J-2000J 7/91	HWES	50	CREG
	Methylene chloride	3 mg/kg	HWES	93	CREG
	PCB (Aroclor 1254)	0.780J	HWES	0.091	CREG
	Beryllium	0.17-0.38	HWES	0.16	CREG
	Lead	23.3-676	HWES	None
	Vanadium	30.6-54.5	HWES	None
	Zinc	61.5-608	HWES	None
On-Site Surface Water, ppb				ppb
OU5, 1	2-methylnaphthalene	45 ppb	HWES	20	LTHA, naphthalene
	Methylene chloride	6B-9B ppb	HWES	4.7	CREG
	Bis(2-ethylhexyl)phthalate	2J-6J ppb	HWES	2.5	CREG
	Beryllium	0.30-0.30 ppb	HWES	0.0081	CREG
	Lead	2.2-779.0 ppb	HWES	None

At Area 52, one monitoring well was installed in 1987. A follow-up investigation in 1988 led to the installation of nine monitoring wells and to the completion of an electromagnetic survey to map the extent of any free product lens (34). Phase I area characterization was completed in August 1990 and included the installation and sampling of six monitoring wells. Nine monitoring wells were installed at Area 52 between December 1990 and January 1991 for Phase II (Appendix A, Figure 14).

Free-phase petroleum hydrocarbons are present beneath most of Area 52. The JP-5 constituents include benzene, chlorobenzene, 1,4-dichlorobenzene, 1,3-dichlorobenzene, 1,2-dichlorobenzene, ethylbenzene, toluene, m-p-xylene, and o-xylene at concentrations 10-2000 times comparison values. Product varies in thickness up to 1.5 feet and may extend 300 feet southwest to a local surface depression and 300 feet northeast toward the intersection of Saratoga and Charles Porter Way (34). Low levels of total xylenes (0.37J-0.78J ppb) were detected in intertidal drive point samples to the north of the area (34). Groundwater under Area 52 flows from east-southeast to north-northwest, discharging to the Strait of Juan de Fuca. High tide reverses flow toward the northeast and southwest for limited periods of time (34).

Table 19. Contaminant Concentrations at Operable Unit 5

OU, Area	Contaminant	Min&Max Level for Each Contaminant	Reference	Comparison Value	Source
On-Site Groundwater Monitoring Wells, ppb				ppb
OU5, 1	Methylene chloride	8B-10B ppb	HWES	4.7	CREG
	Bis(2-ethylhexyl)phthalate	2-90	HWES	2.5	CREG
	Antimony	20.6-20.6	HWES	3	LTHA
	Arsenic	2.0-12.4	HWES	11	RMEG
	Barium	14.1-120	HWES	2500	RMEG
	Beryllium	0.30-0.31	HWES	0.0081	CREG
	Total Chromium	10.6-175.0	HWES	100	LTHA (CrVI)
	Lead	3.7-63.4	HWES	None
	Nickel	17.1-102.0	HWES	100	LTHA
	Thallium	0.40-0.45	HWES	0.4	LTHA
	Vanadium	6.4-48.0	HWES	20	LTHA
	Zinc	79.4-4440	HWES	2100	LTHA
OU5, 52	Benzene	ND-2800J	Hart Crowser	1.2	CREG
	Bis(2-ethylhexyl)phthalate	ND-33B ppb	Hart Crowser	2.5	CREG
	cis-1,2-dichloroethene	ND-7 (4/90, 12/90)	Hart Crowser	0.38	CREG
	Chloroform	ND-5 (4/90, 12/90)	Hart Crowser	5.7	CREG
	Vinyl Chloride	ND-63 (4/90, 12/90)	Hart Crowser	0.7	EMEG
	Carc. PAH	ND-7.5 (4/90, 12/90)	Hart Crowser	0.006	CREG (BaP)
	Naphthalene	ND-670	Hart Crowser	20	LTHA
	2-methylnaphthalene	ND-1000	Hart Crowser	20	LTHA
	Chlorobenzene	ND-25,000J	Hart Crowser	700	RMEG
	1,4-dichlorobenzene	ND-300,000J	Hart Crowser	75	LTHA
	1,3-dichlorobenzene	ND-150,000J	Hart Crowser	600	LTHA
	1,2-dichlorobenzene	ND-650,000J	Hart Crowser	600	LTHA
	Ethylbenzene	ND-170,000J	Hart Crowser	700	LTHA
	Toluene	ND-120,000J	Hart Crowser	1000	LTHA
	Total xylenes	ND-780,000J	Hart Crowser	10,000	LTHA

Below the free product layer, to the west, northwest, and southwest of Area 52, several organic chemicals were detected in groundwater. Compounds detected above comparison values include the jet fuel constituents benzene, ethylbenzene, xylene, and naphthalene, and non-jet fuel compounds vinyl chloride, 1,2-dichlorobenzene, and carcinogenic PAHs (Table 19). The highest level of chlorinated organic compounds was detected down gradient of three potential areas that were past solvent-waste disposal areas. The PAHs are from an area north of the area that receives jet exhaust or automobile exhaust from the test cell, runways, and Saratoga Street.

Hazardous Waste Evaluation Study (HWES).

Twenty-six areas are being investigated to confirm the absence or presence of contamination (Appendix A, Figure 8). Twenty-one of the areas under investigation are on Ault Field, and five are on Seaplane Base. In April 1987, during the CSR, 12 groundwater monitoring wells were installed in the Ault Field Central Core Area. The Navy thought the Central Core Areas could potentially contaminate shallow groundwater and Base Well No. 4 (2). The Central Core Areas are part of the 26 areas in the HWES. HWES sampled subsurface (>3 inches depth) soils, sediments, surface water, and groundwater, analyzing them for EPA Target Compound List analytes. Tests included VOCs, SVOCs, pesticides, PCBs, and metals.

HWES Subsurface Soil

The HWES identified VOCs and metals in subsurface soil from the Ault Field Central Core Area. Several metal concentrations were above relevant comparison values. At Ault Field, soils from less than 1 foot depth were sampled at several areas. Arsenic (2.1-11.9 mg/kg), beryllium (0.34-0.61 mg/kg), and lead (2.5-107.0 mg/kg) were detected. The highest concentrations came from flight line areas in the Ault Field Central Core. The lead concentration at Area 13 was the highest detection in soil in the HWES Ault Field areas. During the CSR, soil samples were collected at Area 25 (Building 120 Transformer Service Area) in the Ault Field Central Core Area while drilling monitoring wells. Concentrations of PCBs were below comparison values. The HWES did not detect PCBs at Area 25 (13).

At Area 53, Polnell Point Ordnance Burn Area, subsurface soils were tested for ordnance compounds. No contamination was found, and no groundwater was encountered. HWES recommended no further sampling except to remove the burn bins (13).

HWES Soil Gas

During the HWES, soil gas was sampled from November 19 to December 11, 1990 at 16 of the HWES areas (16); 93 locations were evaluated. Soil gas samples were analyzed for VOCs and solvents, and the results were used to select boring and monitoring well locations. Each sample was tested for target VOCs based on area history. Sample depths ranged from 1 to 12 feet. A total of 110 soil gas samples were analyzed for VOCs. VOCs within soil were detected at various IRP areas in the Central Core Area and Seaplane Base. Benzene (25 ppm), ethylbenzene (5,300 ppm), and tetrachloroethylene (1 ppm) were detected in the Central Core Area.

HWES Surface Water

Bis(2-ethylhexyl)phthalate (2J-250E ppb) was detected in a surface water sample from a stream that originates from a spring beneath Area 9, Asphalt Plant Disposal Area. Other SVOCs (1-17 ppb) that could be laboratory contaminants were also detected in surface water. Methylene chloride was detected at 2-5 ppb, but was also detected in QA/QC samples that serve to verify data reliability (13). The Navy did not sample the drainage ditch at Area 15, PD-680 Spill. Further field investigations for ordnance compounds including Otto fuel were recommended by the Navy ⁽³⁶⁾.

HWES Groundwater - Monitoring Wells

Ault Field Central Core Area (Appendix A, Figure 9). The maximum levels for cadmium (<0.05-2.7 ppb), chromium (<.05-31 ppb), and lead (<1-32 ppb) were detected in wells in the southwestern part of the area (2). In 1965, a fuel spill from Area 13, Fuel Farm 3 in the Central Core Area, flooded the theater parking lot and basement (Building 118). Two monitoring wells are north and down gradient from the area; a third monitoring well was installed next to the theater building by the HWES. The northwest well has 2.5 feet of floating product in it (13). No petroleum hydrocarbons were detected in other wells. The Navy proposes to remove the floating product.

Several metals in groundwater sampled during the HWES are above comparison values. The highest concentrations of metals are associated with fuel spill areas or the flight line Ault Field Central Core Areas. The highest concentrations of nine metals in groundwater monitoring wells were from Area 18, Ault Field Nose Hanger, which is on the flight line runway area. Those Area 18 metals include arsenic (194 ppb), beryllium (8.2 ppb), cadmium (6.7 ppb), unspeciated chromium (962 ppb), manganese (14,500 ppb), nickel (2030 ppb), and vanadium (1270 ppb), which were above comparison values. Lead was detected at 285 ppb, which is above the EPA action level of 15 ppb.

Groundwater is currently not in use in the Central Core Area. Base Well No. 4 was sampled during the Current Situation Report in 1987, and unspeciated chromium (1.6 ppb) was detected below comparison values. Lead was detected at 5 ppb, which is below the EPA action level.

On-Site Biota

The Navy did not sample on-site food chain entities.

C. Off-Site Contamination

ATSDR searched the Toxic Chemical Release Inventory (TRI) to identify facilities that could contribute to the contamination at NAS. EPA developed the TRI database from chemical release information provided by certain industries. This database includes the annual quantity of toxic chemicals discharged into each environmental medium (e.g., air, water, land) by manufacturing facilities that employ more than ten people and are in Standard Industrial Classification Codes 20 through 39. NAS Whidbey Island is not a manufacturing facility and therefore not subject to that reporting requirement. The information for this search includes data for 1987-1990. No chemical releases were recorded in Island County for the NAS contaminants detected above comparison values.

Off-Site Sediment

In 1987, during the Current Situation Report, intertidal and subtidal sediment samples were collected from Oak Harbor and Crescent Harbor as part of the Seaplane Base area investigation. Subtidal sediments were analyzed for cyanide, metals, VOCs, PCB, pesticides, base acid neutral extracts, and petroleum hydrocarbons. Arsenic (3.6-19 mg/kg) and lead (1.8-7.3 mg/kg) were detected in core samples of sediment from Oak Harbor and Crescent Harbor. Maximum levels for arsenic and lead were detected in the core samples from Crescent Harbor. Cadmium (0.02-0.32 mg/kg), chromium (11-44 mg/kg), and nickel (15-51 mg/kg) were also detected. Arsenic, chromium, and nickel are below comparison values. Lead concentrations are shown in the table of contaminants because ATSDR has not developed ingestion and dermal contact comparison values for lead that is detected in sediment. No VOCs, base-acid-neutral extractables, pesticides, or PCBs were detected in sediment samples (2).

Off-Site Surface Water

Off-site surface waters were sampled in spring and summer of 1992 (32). Results from those samples were not available at the time this Public Health Assessment was being written.

Off-Site Shellfish

Samples of mussels, horse clams, little neck clams, and butter clams at 14 stations from Oak Harbor and Crescent Harbor were collected during the CSR in 1987. Arsenic, cadmium, and lead levels are below the background levels cited in the CSR for Puget Sound shellfish (Table 20). Only chromium (0.19-3.3 mg/kg) and nickel (0.42-2.7) were above the stated Puget Sound reference concentrations of 0.5 mg/kg and 0.91 mg/kg, respectively. The highest chromium value was from a single butter clam sample; however, chromium was detected at a lower level in the duplicate butter clam sample from the same station. The CSR says that the highest chromium value could have resulted from sampling or analytical error (2). Chromium was above reference values at five stations around the western Seaplane Base peninsula. Nickel was detected above reference values in samples from nine sites. Bis(2-ethylhexyl)phthalate (0.3 mg/kg) was detected in a single mussel sample taken near Area 53, Polnell Point. No VOCs, pesticides, or PCBs were detected in shellfish samples at the detection limits used (which were not given). Additional shellfish and fish sampling is scheduled for the RI for OU4 in 1992. No pesticides or VOCs were detected in shellfish samples analyzed during the CSR.

Table 20. Contaminant Concentration in Off-Site Shellfish

	Oak Harbor	Crescent Harbor
Contaminant	Min&Max Level 6/87 mg/kg	Min&Max Level 6/87 mg/kg	Puget Sound Reference Conc. mg/kg	Reference	Comparison Value
					mg/kg	Source
Arsenic	0.48-1.3	0.4-2.7	32.0	CSR	None
Cadmium	0.13-0.68	0.08-0.89	1.3	CSR	None
Lead	<0.04-<0.05	<0.04-0.13	1.3	CSR	None
Mercury	<0.01-<1.01	<0.01-0.08	0.12	CSR	None
Nickel	0.86-1.7	0.42-2.7	0.91	CSR	None

Off-Site Groundwater - Monitoring Wells

The Navy sampled and analyzed off-site groundwater during the RI for OU1. Seven off-site shallow aquifer monitoring wells, installed during a 1988 EPA investigation of Oak Harbor Landfill, were sampled during the OU1 RI. Oak Harbor Landfill forms part of the southern boundary of Area 6 and NAS (Appendix A, Figure 15). The highest vinyl chloride concentration (3.79 ppb) came from the Oak Harbor landfill monitoring well near the southwestern corner of Area 6 (Table 21). The highest arsenic and lead concentrations came from monitoring wells in the north central part and southeast part of Oak Harbor landfill, respectively. Four monitoring wells were installed during the RI for OU1 west of Area 6. The highest lead and zinc levels came from a monitoring well about 800 feet southwest of the Area 6 former hazardous waste storage area.

Off-Site Groundwater - Private Wells

The Washington State Hazardous Waste Cleanup Act directs the Department of Social and Health Services (DSHS) to monitor drinking water supplies potentially affected by releases of hazardous chemicals. In October 1988, DSHS sampled 13 drinking water wells within a 1-mile radius of Area 6 and the Oak Harbor landfills to assess the impact of potential contaminant migration from OU1 (36). Most of the wells were screened in the shallow aquifer, two or three were in the intermediate aquifer, and one well intercepted the deep aquifer. No VOCs were detected in any of the drinking water wells. Bis(2-ethylhexyl)phthalate (8 ppb) detected in one well and QA/QC sample (4000 ppb) were attributed to laboratory contamination or plastic well casing (Table 21). Arsenic was detected at levels (ND-24 ppb) below the EPA drinking water MCL (50 ppb) (36).

Table 21. Off-Site Contaminant Concentrations in Groundwater at Operable Unit 1

OU, Area	Contaminant	Min&Max Level for Each Contaminant	Reference AII, 6/90 RI, 7/91	Comparison Value, ppb	Source
Off-site Groundwater - Monitoring Wells near OU1, ppb
	Vinyl chloride	ND-3.79	AII, IA, RI	5	CREG
	Arsenic	2.5BJ-6.1BJ	AII, IA, RI	0.02	CREG
	Cadmium	ND-9.8J	AII, IA, RI	7	EMEG
	Lead	1.3B-103J	CSR, AII, IA, RI	None
	Zinc	ND-4400J	AII, IA, RI	2100	LTHA
Off-site Groundwater - Private and Public Potable Wells near OU1, ppb
	Arsenic†	ND-34, 10/88, 12/92	Hulsman	0.02	CREG
	Lead	ND-24, 5/91	Hulsman	None
	Lead	ND-5, 12/92	Hulsman	None
	Manganese	ND-499, 10/88, 11/89	Hulsman	50	RMEG (child)
	Nitrate	ND-13,200, 12/92	Hulsman	10,000	MCLG
†WDOH research indicates background arsenic levels for Island County range from 11-45 ppb 39

Seven drinking water wells were sampled in November 1989 by DSHS; three of those wells were also sampled in October 1988. At least one well was drawing water from the shallow, intermediate, and deep aquifers (37). Chloroform (30.7 ppb), methylene chloride (0.9 ppb) and toluene (10.1 ppb) were detected in one well, and are believed to be from the preservative or residual manufacturing coatings, or oils or solvents from the installation of a new pump that had been placed in the well before the sampling (38).

In May 1991, 17 drinking water wells were analyzed by DSHS. Several wells were sampled in the previous investigations. Chloroform (1.5 ppb) and 1,1,1-trichloroethane (0.5 ppb) were detected in one well. The owner of the well had chlorinated the well just before the sample was taken, and there used to be an automobile repair shop on the property (37). Dichlorodifluoromethane (3.1 ppb) was detected in another well (37). Lead (ND-24 ppb) was detected in five wells. Those levels of chloroform, 1,1,1-trichloroethane, and dichlorodifluoromethane are not above comparison values. In previous investigations of wells, lead levels were below detection limits (<5, <2 ppb). ATSDR does not know if this is a seasonal variation, a result of sampling or analytical techniques, or contamination from an on- or off-site source. DSHS reported there were no organic compounds of any significance in the drinking water wells, and levels of inorganic compounds were within the range of natural background levels for the area. DSHS concluded that the drinking water wells did not appear affected by contaminants from NAS or Oak Harbor landfills.

In December 1992, the Washington Department of Health (WDOH) sampled 19 off-site drinking water wells near Area 6. The samples were analyzed for dissolved and total metals, inorganics, and VOCs. VOCs were detected below comparison values in three wells; the sources of the contamination are not known. Two of those wells were abandoned soon after they were sampled. The well owner monitors the third well quarterly as part of the WDOH VOC Monitoring Program. Arsenic (detected in six wells) and manganese (detected in 13 wells) were detected above comparison values. WDOH considered all metals detected to be consistent with those for background for Whidbey Island. The maximum lead concentration detected in this round of sampling was 5 ppb. WDOH detected nitrate in nine drinking water well samples; one sample contained 13.2 ppm, which is above comparison values. WDOH said that the nitrate detections were an indication of contamination of the wells from surface sources (39) which were not stated in the report. The source of the nitrate contamination is not known.

Off-Site Ambient Air

Off-site ambient air measurements were taken as part of the monitoring at Area 6 during August 14-17, 1991. One ambient air sampling station was off site about 1000 feet to the northwest of the former hazardous waste storage area. Samples collected at that station detected 1,1,1-trichloroethane (ND-0.00074 ppb), chloromethane (0.29 ppb), and toluene (0.78-1.6 ppb) below comparison values. ATSDR has not developed inhalation comparison values for Freon 113 (0.33 ppb) and freon 12 (0.90-1.1 ppb) in air. Other VOCs were not detected. The Industrial Source Complex Short-Term air dispersing model (ISCST) was used to evaluate the impact of VOCs on the nearest people to Area 6, about 3300 feet south-southeast (Auld Holland Inn) of the site. There were no sample stations at or near that site. The Navy used 1,1,1-trichloroethane in the study, because it was frequently detected. Actual measurements of 1,1,1-trichloroethane stated in previous paragraphs were higher than modeled results and below comparison values (6).

D. Quality Assurance and Quality Control

In preparing this public health assessment, ATSDR relies on the information provided in the referenced documents. Some references used to develop this public health assessment were preliminary documents that were undergoing Navy, EPA, and state review. The Agency assumes that adequate quality assurance and quality control measures were followed with regard to chain-of-custody, laboratory procedures, and data reporting. The validity of the analysis and conclusion drawn for this public health assessment is determined by the availability and reliability of the referenced information.

During the Interim Investigation of subsurface soil analyses at Operable Unit 1, the VOC acetone was detected in 12 of 20 method blanks at concentrations from 14-29 ppb, and methylene chloride was detected in all 20 method blanks from 5-22 ppb. No other interferences were detected. The SVOC bis(2-ethylhexyl)phthalate (BEHP) was detected in 6 of 18 method blanks in concentrations from 40-9000 ppb and in field QC sample blanks from 2-270 ppb. Those compounds were detected in 14 of 18 method blanks associated with soil and field quality control samples (10). More recent sampling results and review of data validation has clarified the quality assurance/quality control questions and the Final RI report (June 1993) provides additional information.

The review of OU1 analytical results for soil and groundwater sampling of the Initial Investigation was complicated by the contamination of several quality assurance samples analyzed with the environmental samples. All results of collected soil samples are suspected to be a result of laboratory contamination or interferences; therefore, the soil data cannot be conclusively used to show the presence of contamination in the area (10).

According to the RI for OU1, Quality Assurance measurements for reported soil gas VOC concentrations appear to be accurate (6); however, the quality of laboratory results of other media varied throughout the RI. Much of the data was qualified or rejected during data validation. Seventy percent of the organophosphorus and herbicide results were rejected due to holding time or instrument calibration deficiencies (6). To use the data, more lenient validation criteria were used in the data validation process, resulting in previously rejected Phase I data being labeled 'estimated' during Phase II (6). The Navy says that toluene results from soil samples at OU1 are due to toluene-containing tape used to seal the sampling containers (6).

Data from OU2 RI/FS are not validated. Data are used in this public health assessment for qualitative interpretation of OU2 characterization. Remedial actions are being discussed based on the data (30).

Phase I field work data for OU4 were invalidated by 'catastrophic laboratory failures'. Two interim sampling events were conducted to close data gaps caused by the data invalidated in Phase I (7). Data from the Technical Memorandum for OU4 were not validated (14). The data are used in this public health assessment for qualitative interpretation of OU4 characterization.

At OU5 Area 52, bis(2-ethylhexyl)phthalate was detected in 35% of the groundwater samples collected in concentrations from 6.9 to 33 ppb. The levels detected were not consistent in Phase I and Phase II sampling and are likely introduced during laboratory analysis (34). Laboratory QA/QC data evaluation procedures indicate that the soil concentrations of methylene chloride (0.002-0.004 mg/kg) and acetone (0.010-0.053 mg/kg) were also due to laboratory contamination.

Weather during soil gas sampling for the HWES may have affected results (16). High winds, cool temperatures, and heavy rains occurred during most of the soil gas survey during the HWES. QA/QC consisted of eleven duplicates and one sample of ambient air. The report for the HWES for other media contained several data inconsistencies between analytical tables and summary tables. Units were different between two tables when discussing the same contaminant in the same area. The Installation Restoration Program coordinator said that the report was being revised (40).

E. Physical and Other Hazards

During the site visit, the ATSDR team observed that tidal and wave action at Area 1, Beach Landfill, had uncovered buried landfill items such as an old telephone pole, lumber, and pieces of metal and concrete. The area is not fenced, and access is not restricted. The terrain drops down to the beach very steeply in places. Base personnel could fall and hurt themselves on the exposed debris.

According to the Initial Assessment Study, live ordnance is sent to the Yakima Firing Range for disposal (1).

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