PUBLIC HEALTH ASSESSMENT

PLATTSBURGH AIR FORCE BASE
PLATTSBURGH, CLINTON COUNTY, NEW YORK

EVALUATION OF ENVIRONMENTAL CONTAMINATION, EXPOSURE PATHWAYS, AND THE PUBLIC HEALTH IMPLICATIONS

INTRODUCTION

This report is organized by exposure situations. Exposure situation is used to describe conditions and circumstances by which people could come in contact with contaminants. These situations are discussed in the order of their public health importance. The exposure situations and the areas at which they occurred are listed below. The term site is used to describe a distinct area to which Plattsburgh Air Force Base has assigned a reference number.

In preparing this public health assessment, ATSDR relied on the information provided in the referenced documents. Some references used to develop this public health assessment were PAFB's preliminary documents that were undergoing Air Force, EPA, and state review. ATSDR 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 analyses and conclusions drawn for this public health assessment is determined by the availability and reliability of the referenced information.

During the environmental investigations at PAFB, 40 sites were identified for investigation. Twenty-four sites are governed under CERCLA. Nine sties are fuel spill sites under NYSDEC. The remaining seven were identified during the Preliminary Assessment and the Environmental Baseline Survey. Environmental sampling was conducted at sites where there was strong evidence to suggest environmental contamination. The 40 sites that warranted inclusion into the Installation Restoration Program required environmental sampling to characterize the nature and extent of contamination. All sites are evaluated to determine extent of contamination for cleanup during the feasibility study phase(5).

ATSDR reviewed the available environmental data and information gathered during our site visits, document reviews, discussions with stakeholders, and from our visual inspections, we identified six situations that have potential for human exposure. The body of the report discusses our evaluation of four exposure situations where past or current exposure has or is occurring. Additionally we evaluated potential future exposures for two possible exposure situations. Of these six situations, exposure was identified at two off base areas unrelated to base activities. Appendix B describes our evaluation of all areas.

During our investigation, discussions, and evaluation of information related to Plattsburgh Air Force Base, we identified two exposure scenarios not caused by contaminants from PAFB yet needed to be included in this document because of the population affected and their close proximity to PAFB. These two exposure scenarios, at Kemp Lane and Runway Drive have been investigated by the NYSDEC and NYSDOH. PAFB has also collected numerous samples to confirm that contaminants were not migrating off base into these areas.

ATSDR assigns conclusion categories to sites based on their public health hazard. At Plattsburgh AFB, we have concluded that the areas on base pose "No Apparent Public Health Hazard" because even though exposures have occurred or are occurring, levels to which people are exposed are too low to result in adverse health effects.

ATSDR categorizes each exposure situation based on the specific exposure and its relative level of public health hazard. Additional information describing ATSDR's public health conclusion categories is provided in Appendix C. Below is a list of the ATSDR's public health conclusions for the exposure situations identified during our investigation at PAFB. A detailed discussion of each situation is included in the body of this document.

Table 1. Summary of ATSDR's Public Health Conclusions for PAFB.

CONCLUSION CATEGORY	SITUATION
No Apparent Public Health Hazard	I. Kemp Lane Neighborhood - Past and Current Exposure to Contaminated Drinking Water (Off-base) II. Runway Drive Neighborhood - Past, Current, and Future Exposure to Contaminated Drinking Water and Possible Indoor Air (Off-base) III. Flightline/Golf Course Drainage - Past, Current, and Future Exposure to Contaminated Surface Water (Off-base Cliff Haven Community) IV. Fire Training Area FT-002 - Current Exposure to Contaminated Groundwater and Possible Indoor Air Contamination (On-base Buildings)
No Public Health Hazard	I. Fire Training Area FT-002 - Future Exposure to Possible Groundwater Contamination (Off-base Private Wells East and Southeast of the base) II. Former Base Exchange Service Station ST-030 - Future Exposure to Possible Indoor Air Contamination (On-base homes)

Figure 1. Plattsburgh Air Force Base

EVALUATION OF ENVIRONMENTAL CONTAMINATION, EXPOSURE PATHWAYS, AND THE PUBLIC HEALTH IMPLICATIONS

1. No Apparent Public Health Hazard: Kemp Lane - Exposure to Contaminated Drinking Water (Off-base)

Chemical contaminants detected in the private wells serving homes on Kemp Lane, are at low levels and do not pose a health hazard. Sampling of Kemp Lane private wells has been ongoing since 1990 and contaminant levels have remained constant and below federal Safe Drinking Water Act standards. In March 2000, during our follow-up discussions with Kemp Lane residents, ATSDR received complaints of foul odor and taste from water obtained from one of the private wells. ATSDR relayed the complaints to NYSDEC and NYSDOH. NYSDEC immediately sampled the taps and installed carbon filters on the home system. NYSDEC in conjunction with NYSDOH is working to ensure that people in the Kemp Lane area drinking from private wells do not drink contaminated water at levels that pose a health hazard.

Background

Kemp Lane is a residential area off of South Peru Drive, just outside of the north gate of the former PAFB (Map 2). It is a community of ten homes, approximately four of which rely on private wells for their drinking water supply. The surrounding community and the former PAFB are served by the town of Plattsburgh public water supply(3).

Sampling History and Public Health Implications

Periodic private well sampling on Kemp Lane was initiated by the NYSDOH in 1990. The results demonstrate low-level solvent contamination in some of these wells. The chemicals detected include trichloroethylene and dichloroethylene which are classified as volatile organic compounds (VOCs). Concentrations in private wells have never exceeded 2.0 parts per billion (ppb) and typically are less than 1 ppb. Using the Safe Drinking Water Act (SDWA) standards for public water supplies as a basis for comparison, (5 ppb for these and many other VOCs) the concentrations detected in wells on Kemp Lane are below the drinking water standards for these chemicals. Therefore, the well water supplies for these homes do not pose a public health hazard. Levels of contaminants have remained constant over the last 10 years.

The source(s) of contamination in the Kemp Lane wells has not been identified. Groundwater flows from PAFB into the Kemp Lane neighborhood at the neighborhood's western property line. While there is no evidence to date that groundwater contamination in the neighborhood is attributable to PAFB, neither is the evidence conclusive at this point that PAFB is not responsible for contamination in the neighborhood(7). To help determine groundwater flow and base contribution to Kemp Lane's low level contaminants, PAFB is planning to install additional monitoring wells (one or more) between SS-016 and the base boundary. Potential off-base sources include a trucking (freight) company which abuts the residential properties on the northeast side of Kemp Lane.

Because the private wells are dug wells or very shallow, they are more susceptible to light contamination. Another common source of private well contamination in other communities stems from improper disposal or accidental spilling of chemicals by residents or their neighbors.

These activities may include car maintenance, furniture restoration, and painting activities and this type of contamination scenario is referred to as "self-contamination". It is not known if these types of homeowner activities have impacted the groundwater at Kemp Lane.

Based on several groundwater samples, nearby on-base areas of contamination such as the Alert Area Dump (OTH 2895), the Alert Area Aircraft Parking Ramp (SS-014), and the Nose Dock 8 site (SS-016) have not been found to contribute contamination to Kemp Lane. These areas of the former base are located to the west and southwest of Kemp Lane. Investigations conducted by the AFBCA concluded that groundwater contamination from these sites is not contributing, or likely to contribute in the future, to the chemicals in groundwater at Kemp Lane (8,9,10). PAFB has agreed to install a number of additional monitoring wells in the future in an attempt to conclusively determine that contamination is not migrating into the Kemp Lane neighborhood from the base.

Investigational results described in the OTH-2895 report provides groundwater elevations and flow maps for this part of the base(10). Relative locations of the Alert Area Dump and SS-016 to Kemp Lane make groundwater migration from OTH-2895 and SS-016 unlikely. Limited groundwater contamination was detected during OTH-2895 investigation and was located well side-gradient of actual debris area. Detailed groundwater plume modeling has been performed for IRP Site SS-016 and shows the contamination to be flowing southeast to the center of the base, away from Kemp Lane (8,9).

The AFBCA has established a line of groundwater monitoring locations between these two sites and the Kemp Lane homes in order to monitor the movement of contaminants. These monitoring locations are proposed for semiannual monitoring permitting the early identification of any contaminants that may migrate toward the residences and ample time to prevent any impacts on well water quality and public health from contaminants migrating from the base.

However, there are no groundwater monitoring locations between the freight company property and Kemp Lane and the effects of private well use on Kemp Lane on local groundwater flow patterns have not been determined in this area. Therefore, if releases of chemicals are occurring or have occurred in the past on properties to the east and northeast of Kemp Lane, the potential exists for such releases to impact residential wells.

Although since 1991, levels of contaminants do not pose a health hazard, NYSDEC has taken proactive measures in the best interest of prudent public health practice by installing home system filtration units. Of the ten homes that were using private wells in 1990, approximately four homes are currently using groundwater. One of the homes is used during the day as a day care for approximately six children. Other homes were either hooked up to Town of Plattsburgh water, torn down, or abandoned due to death of the owner (11). ATSDR is discussing with NYSDEC, NYSDOH, and the Town of Plattsburgh future plans for follow-up and perhaps hooking-up to public water supply lines so that people will not be exposed to contaminants in the shallow groundwater.

Figure 2. Kemp Lane Neighborhood (off-base)

Table 2. No Apparent Public Health Hazard: Kemp Lane - Exposure to Contaminated Drinking Water (Off-base)

PATHWAY NAME	CONTAMINANTS	EXPOSURE PATHWAYS ELEMENTS					TIME	COMMENTS
		SOURCE	ENVIRONMENTAL MEDIA	POINT OF EXPOSURE	ROUTE OF EXPOSURE	EXPOSED POPULATION
Kemp Lane - Exposure to Contaminated Drinking Water (Off-base)	Solvents (methylene chloride, 2-butanone, toluene, xylenes, ethylbenzene, trichloroethylene, acetone)	Potential sources include: (i) Releases of waste solvents from privately owned off-base trucking company on Kemp Lane where trucks are maintained and repaired (ii) Accidental self-contamination by Kemp Lane residents inoperable automobiles stored in yards iii) Unknown areas on PAFB	Groundwater	Residential taps in homes on Kemp Lane	Drinking contaminated water Inhalation of volatilized fumes from the contaminated groundwater Direct contact with the contaminated groundwater	Adults and Children residents and visitors in the homes on Kemp Lane which utilize private water wells Estimated 4 homes one home operates a day care center serving 5-10 children ages newborn to 12 years old (Approximately 12 residents and 10 visiting children) [1990 Census demographics for Tract 1012, Block Groups 4 and 5 which include Kemp Lane area]	Past Current Future	Well sampling is conducted by the NYSDEC every few years. Wells on Kemp Lane were first sampled in 1990 and have been sampled six times since by the NYSDOH and NYSDEC. Concentrations of VOCs detected in the water samples typically ranged from 1-2 ppb. These concentrations are below state drinking water standards. In March 2000, NYSDEC resampled one residence due to complaints of foul odor and taste. Installed home filter on taps. Discussions underway to install public water lines (Town of Plattsburgh) to remaining homes using private wells.

Conclusion and Public Health Action Plan for
Kemp Lane - Exposure to Contaminated Drinking Water (Off-base)

2. No Apparent Public Health Hazard: Runway Drive Neighborhood - Exposure to Contaminated Drinking Water and Possible Indoor Air (Off-base)

People living in the Runway Drive neighborhood were exposed to fuel related contaminants in their drinking water at low levels that do not pose a public health hazard. Past and possible current exposures are to drinking water contaminants at levels below drinking water standards and are not likely to result in adverse health effects. Fuel was released from leaking underground storage tanks and associated lines at the Mobil Service Station (08-L78) located on Route 22 uphill of the Runway Drive neighborhood. In 1990, fuel tank levels indicated a fuel leak. Mobil Oil Corporation project engineers with oversight from NYSDEC pumped free floating product from the groundwater. Semiannual sampling of monitoring wells was conducted as well as sampling of private residential wells for several residents on Runway Drive. The site environmental investigation was closed out and routine sampling ended in 1998 when monitoring wells at the source and downgradient showed levels to be below drinking water standards. Additionally, indoor quality in Runway Drive homes does not pose a health hazard because groundwater levels under homes remained non-detectable to consistently low.

Background

In 1990, fuel tank levels indicated a fuel leak at the Mobil service station (08-L78) located on Route 22 uphill of the Runway Drive neighborhood, west of the PAFB boundary (Map 3). Releases of fuel from the service station contaminated the soils and shallow groundwater. The groundwater contamination spread toward the east/southeast and onto the former PAFB. Inside the base boundary, this fuel plume has comingled with an on-base plume of groundwater contaminants from the LF-023 site, a former landfill which has been closed by the AFBCA (12,13,14).

A residential community, comprising homes on Runway and Debra Drives, and Tammy Lane, is located between Route 22 and the western border of the former PAFB, south of the service station. These homes are downhill of both the service station and LF-023. Water service on Runway Drive, Tammy Lane, and Debra Drive is provided by a water system served by a common well.

ATSDR investigated the possible exposure of Runway Drive residents to drinking water and indoor air contaminants because of the nearness of the community to both the off-base service station fuel plume and the on-base landfill, LF-023.

Sampling History

Water Supply:
Between1992 and 1994, Mobil Oil Corporation contractors installed twelve monitoring wells at the source, upgradient, and downgradient of the source. It is unknown how long the fuel had leaked from underground storage tanks and associated lines before it was discovered. The Service Station has operated since 1968. Mobil Oil Corporation project engineers, with oversight from NYSDEC, removed contaminated soil, pumped free floating product from the groundwater, and conducted quarterly sampling of the monitoring wells since 1995. Quarterly monitoring is ongoing. PAFB has routinely conducted groundwater sampling at LF-023 as part of their Installation Restoration Program (15).

NYSDOH conducted routine sampling of tap water from several private residences along Runway Drive. Concentrations of volatile organic compounds were detected in several homes, all below Safe Drinking Water Act standards (16).

Information from monitoring wells indicated a southeastern groundwater flow toward PAFB and away from Runway Drive. Sampling data from both monitoring wells and private wells in the Runway Drive neighborhood validate the groundwater flow direction information. While the groundwater flow direction is not toward the Runway Drive residents, small amounts of contaminants diluted by the groundwater movement may be detected. Therefore, possible future releases from the service station may only slightly or not at all impact the Runway Drive neighborhood (14).

Environmental investigation of the service station was closed out and monitoring ended in 1998 when monitoring wells at the source and downgradient showed levels to be below drinking water standards. However, NYSDOH periodically samples the well water in the Runway Drive community to ensure that the water supply is safe for use (14,15). This continued sampling has determined that the concentrations of contaminants are dim inishing.

Indoor Air:
ATSDR evaluated the likelihood for indoor air to become contaminated from two routes; 1) the volatile contaminants in the shallow groundwater migrating up through the soil into indoor air and 2) volatile contaminants from the landfill LF-023 migrating as soil gas into indoor air. Based on information available in the current scientific literature, contaminant levels would have to be 1000 to 10,000 time greater than those levels here to migrate up into indoor air. Contaminant levels in groundwater beneath the Runway Drive neighborhood are low and would not present a hazard to indoor air.

ATSDR reviewed the information about LF-023 to determine if soil gas could present a problem. As part of the Installation Restoration Program, PAFB has conducted soil gas sampling at six stations along the base boundary and Route 22 between the landfill LF-023 and the Runway Drive neighborhood (14). Landfill gases may be present from volatile compounds disposed in the landfill and are also made by the natural decomposition of organic material. Gases can migrate from a landfill through soil and become trapped in indoor air. Sampling results do not indicate levels of soil gas high enough to migrate into homes. Therefore, soil gases from the landfill do not pose a public health hazard to Runway Drive neighborhood residents. Additionally, PAFB installed vents to further aid in reducing landfill gas build-up.

Figure 3. Runway Drive Neighborhood

Public Health Implications

ATSDR evaluated the exposure of residents of the Runway Drive neighborhood to contaminants present in drinking water and possible contaminants in indoor air of the homes. Levels of contaminants detected in drinking water are low (below drinking water standards) and do not pose a health hazard. Indoor air contaminants migrating from the fuel plume and landfill, LF-023, are not likely to be present in the Runway Drive neighborhood homes.

Water Supply:
Contaminants detected by the NYSDOH in the Runway Drive neighborhood well water include low levels of methyl tert-butyl ether, naphthalene, acetone, PCE, methylene chloride, and by-products of the chlorination process (16).

Information collected from sampling of monitoring wells indicates that groundwater flow and the flow of contaminants is southeast toward PAFB and away from the private drinking water wells in the Runway Drive neighborhood. The low levels of contaminants detected in the Runway Drive neighborhood confirm these results. Contaminant levels in drinking water have been consistently below the Safe Drinking Water Act standards and are not likely to result in adverse health effects.

Indoor Air:
Contaminants present in the fuel plume belong to a group of chemicals called volatile organic compounds that by nature, readily volatilize into gas. Available scientific literature indicates that groundwater contaminants can be released into indoor air when concentrations of VOCs are extremely high (1000 to 10,000 times higher than those seen in the Runway Drive neighborhood). Based on the low levels of VOCs present in private wells here, it is not likely that VOCs would be released into indoor air.

Additionally, ATSDR evaluated the likelihood of soil gas migration of landfill gases from the on-base LF-023 site. Data from PAFB does not show levels of soil gas likely to present a health hazard to Runway Drive neighborhood residents. In addition, the uniformly sandy soils and lack of buried utilities fail to provide a pathway for soil migration to the homes. Indoor air contamination caused by the fuel plume or the landfill is not a likely occurrence; therefore, would not pose a health hazard.

Future Exposures

Although the major groundwater flow direction is away from the Runway Drive neighborhood, small amounts of diluted groundwater contaminants may be detected in the drinking water. NYSDOH will continue to sample the drinking water of residences within the Runway Drive neighborhood to ensure that contaminant levels continue to diminish, and therefore, people are not drinking water at levels likely to cause adverse health effects. Based on the available information, ATSDR recommends to NYSDOH that the homes closest to the service station be sampled at least every five years.

Table 3. No Apparent Public Health Hazard: Runway Drive Neighborhood - Exposure to Contaminated Drinking Water and Possible Indoor Air (Off-base)

PATHWAY NAME	CONTAMINANTS	EXPOSURE PATHWAYS ELEMENTS					TIME	COMMENTS
		SOURCE	ENVIRONMENTAL MEDIA	POINT OF EXPOSURE	ROUTE OF EXPOSURE	EXPOSED POPULATION
Runway Drive: Exposure to Contaminated Drinking Water and Possible Indoor Air	Fuel-related volatile organic compounds	Releases of fuels from the Route 22 Mobile Service Station	Shallow groundwater (documented)	Household tap water	Drinking contaminated water;	People living in homes in the Runway Drive Neighborhood	Past Current Future	Mobile Oil Corporation, with oversight by the New York State Department of Environmental Conservation (NYSDEC), conducted characterization, monitoring, and cleanup, of the groundwater contamination from the Route 22 Mobile service station. The service station has operated since 1968. The off-base groundwater plume migrated south/southeast and impacted the groundwater on PAFB in the vicinity of LF-023. Water service on Runway Drive, Tammy Lane, and Debra Drive is provided by a water system served by a common well. Contaminant levels have been seen in the drinking water from some homes at levels below safe drinking water standards.
			Soil gas (possible)	Household indoor air	Breathing indoor air possibly contaminated by fumes from the shallow groundwater contamination or landfill, LF-023 gases	People living in homes in the Runway Drive Neighborhood	Past Current Future	Indoor air contamination is not likely because of low VOC concentration beneath homes, and the downhill location of the Runway Drive Community, to LF-023. Additionally, soil gas monitoring and vents reduce gas build up and the possibility for migration 'into homes.

Conclusion and Public Health Action Plan for the Runway Drive Neighborhood -
Exposure to Contaminated Drinking Water and Possible Indoor Air (Off-base)

3. No Apparent Public Health Hazard: Flightline/Golf Course Drainage - Exposure to Contaminated Surface Water (Off-base Cliff Haven Community)

Citizens in the Cliff Haven community have expressed concerns about potential exposure to chemical contaminants leaving the base in the Golf Course Drainage system. ATSDR considered the past, current, and future potential for chemical exposure of recreational users of the lower reaches of the stream C-19 and the beach in the Cliff Haven Community. We concluded that past and current exposure to contaminants in stream does not present a public health hazard to recreational users. Routine monitoring on-base and at the base boundary would allow early detection of chemical releases to help ensure that people are not exposed to future hazardous levels of chemicals released from the base. The Golf Course Drainage System exits across the eastern boundary of PAFB as Stream C-19 and flows through the Cliff Haven residential community before discharging to Lake Champlain at Cliff Haven beach. On base surface runoff, waste water, and groundwater are past, current and future contributors to the flow of Stream C-19 with the types of chemical contaminants in the water being historically varied.

Background

The Golf Course Drainage (SD-001) is a system of multiple channels and ponds located on the east side within the boundaries of PAFB (Map 4). Surface drainage collected by drainage tiles which underlie the runway and ramp and by ditches in the industrial area empties into the Golf Course Drainage system. This combines with storm water runoff from the Golf Course and the streams subsequently converges into a single channel which crosses the eastern boundary of the base. The stream flows under the railroad tracks and Route 9, through the Cliff Haven residential area, and eventually empties into Lake Champlain at a location adjacent to a private community beach. This off-base section of the unnamed stream, designated C-19, measures about 2000 feet in length between the base boundary and Lake Champlain. The area around the stream is wooded except for part of the north bank west of Route 9, which abuts the backyards of several residences. The portions of the stream and beach at Lake Champlain in the Cliff Haven community are the locations where people are most likely to experience recreational contact with chemicals in the water and sediments.

Historically, PAFB discharged several types of waste water into the Golf Course drainage system which flowed downstream into Stream C-19. These waste waters included: (1) aircraft wash water containing detergents, oils, and grease, (2) storm water drainage from the runway and ramp containing residual fuels, oils and greases, and antifreeze, (3) oil, grease, and VOCs from floor drains in aircraft maintenance buildings, and (4) domestic sewage (17,18).

These waste water sources have varied historically with changes in PAFB's handling of waste waters and the eventual closure of the base in 1994. Therefore, the types of contaminants that could potentially enter the stream C-19 also varied.

Figure 4. Flightline/Golf Course Drainage

Table 4. No Apparent Public Health Hazard: Flightline and Golf Course Drainage - Exposure to Contaminated Surface Water (Off-base)

PATHWAY NAME	CONTAMINANTS	EXPOSURE PATHWAYS ELEMENTS					TIME	COMMENTS
		SOURCE	ENVIRONMENTAL MEDIA	POINT OF EXPOSURE	ROUTE OF EXPOSURE	POTENTIALLY EXPOSED POPULATION
PAFB Flightline andGolf Course Drainage: Exposure to Contaminated Surface Water (Off-base Cliff Haven Community)	Multiple contaminants from multiple sites including: oil and grease, detergents, glycols and urea, solvents (VOCs), fuel components, iron, and sewage	1) Aircraft maintenance, deicing, and fueling activities 2) Storm water runoff 3) Shallow groundwater discharges to stream	Surface waters and sediments in stream C-19 which flows from the golf course area to Lake Champlain	Surface waters in the creek, and the point of creek discharge into Lake Champlain (Cliff Haven Beach)	Direct contact Incidental ingestion	Adults and children swimming and wading at Cliff HavenBeach Children playing in the creek between the base boundary and Lake Champlain	Past Current Future	Historically, PAFB discharged several types of waste water into the Golf Course drainage system which flows downstream into stream C-19. PARC currently conducts monthly sampling for phosphorus, ammonia, phenols and total glycols and quarterly sampling for oil and grease, benzene, toluene, xylenes, methyl ethyl ketone, DDT, 2,4-D, nitrogen, and nitrate at Outfall 003.
	Fuel components, trichloroethylene	Aircraft deicing and fueling activities and migration of the FT-002 Ground Water Operable Unit Sources	Surface waters and sediments in stream C-19 which flows from the golf course area to Lake Champlain	Surface waters in the creek, and the point of creek discharge into Lake Champlain (Cliff Haven beach)	Direct contact Incidental ingestion	Adults and children swimming and wading at Cliff Haven beach Children playing in the creek between the base boundary and Lake Champlain	Current Future	Routine monitoring on-base and at the base boundary would allow early detection of chemical releases to help ensure that people are not exposed to future hazardous levels of chemicals released from the base. Past and current exposure to contaminants in stream does not present a public health hazard to recreational users.

PAFB files contain considerable documentation regarding past waste water sources to the Golf Course Drainage System and citizen concerns about water quality downstream in C-19. The earliest letter of community concern in the base files documents a complaint from the Cliff Haven Homeowners Association in 1958. Concerns were expressed about observations of foaming and oily residues in the stream and the smell of fuel odors. Between 1958 and 1977, the Air Force investigated, eliminated, or reduced these discharges. These actions included diverting aircraft wash water, aircraft maintenance building floor drains, and domestic wastes to the Plattsburgh Sewage Treatment Plant. Interceptors to capture oil and grease were also installed. These actions eliminated or reduced the routine discharges of detergents, oils, greases, and sewage to the stream, decreasing the probability that people would come in contact with these contaminants at downstream locations (18). The files also document efforts taken by the Air Force to address those concerns by stopping or reducing the discharges of contaminated waste waters to the creek and through coordination with the Clinton County Health Department to evaluate potential health concerns (18).

Additional measures have also contributed to the decrease in contaminant concentrations in the Golf Course Drainage Ditch. Spill control dams and an aeration system was installed in 1991. Several source remediation actions such as free product recovery, bioventing and soil vapor extraction, located over 1 mile away, have been conducted to help cleanup FT-002. Computer modeling of the FT-002 Groundwater Operable Unit conducted in the RI/FS (Draft Final Report issued February 2000) indicates contaminants in the base streams and groundwater will not migrate off base. Interim sampling of the surface water and groundwater, initiated in 1998, confirms this; interim sampling is ongoing and is part of the proposed remedial action for the FT-002 groundwater operable unit. Monitoring results would act as an alarm if contamination levels become elevated in the future thus, allowing time to take action to prohibit migration of contaminants off base.

Sampling History

Information and chemical data for evaluating the likelihood of past exposures to contaminated drainage derives from three sources: (1) a wastewater characterization study conducted in 1987 (19); (2) a drainage flow study conducted in 1989 - 1990 (20); and (3) State Pollution Discharge Elimination System (SPDES) surface water compliance sampling performed by AFBCA and PARC in the stream where it exits the base. This stream sampling location is designated as Outfall 003 (Map 4). Off-base surface water and sediment samples have been collected in the past near Cliff Haven beach.

Since 1990, PAFB continues to sample the Golf Course Drainage Ditch as part of two distinct initiatives: 1) State Pollution Discharge Elimination System (SPDES) surface water compliance sampling and 2) Remedial Investigations of the Fire Training Area (FT-002) (22). The SPDES permit has been renewed every 5 years with August 1999 as the latest renewal date. Known soil and groundwater contamination have resulted from past spills/activities on the flightline and in the industrial areas of the base (the groundwater components are collectively designated as the Fire Training Area (FT-002) / Industrial Area Groundwater Operable Unit which is currently undergoing remedial investigation and feasibility study under the CERCLA process.

Sampling of the Golf Course Drainage Ditch has been performed for 1) detergents, oil, and grease; 2) deicing compounds (glycols and urea as nitrogen); 3) pesticides; 4) VOCs; 5) iron; and 6) fecal coliforms. As part of the caretaker responsibilities, PARC currently conducts monthly sampling for phosphorus, ammonia, phenols and total glycols and quarterly sampling for oil and grease, benzene, toluene, xylenes, methyl ethyl ketone, DDT, 2,4-D, nitrogen, and nitrate at Outfall 003 (21).

Since operations as an active Air Force Base ceased in 1994 and aircraft deicing activities ended in 1995, the sources of water to the Golf Course Drainage streams have been reduced. Accordingly, there are two potential on-base sources of contaminants to the drainage system and creek. These include (1) VOCs from the FT-002 Groundwater Operable Unit plume, and (2) surface runoff during storm events of herbicides and fertilizers from golf course maintenance activities. These groundwater discharges are supplemented with rain water runoff from the flight line, industrial, and the golf course areas during storm events.

No off-base surface water samples are currently being collected from C-19 near the point of discharge at the Cliff Haven beach. However, PAFB and PARC continue to sample for chemicals at Outfall 003 at the base border. The Site Investigation Report states that "No Further Action" is required at this site. However, PARC continues to monitor the Golf Course Drainage area as part of the State Pollution Discharge Elimination System Permit. (SPDES) permit for wastewater outfalls. The scope of this sampling requirement ensures that the appropriate sampling is being conducted to identify contamination reaching the Golf Course Drainage System and stream C-19.

It is reasonable to assume that the concentrations of VOCs in the Golf Course Drainage System were higher prior to the diversion of aircraft maintenance waste waters to the Plattsburgh Sewage Treatment Plant around 1977. However, it is likely that the releases into the drainage system were periodic rather than constant. This pattern of periodic releases to the drainage system is evident in the wastewater characterization study (19). Although the SPDES monitoring indicated lower concentrations of VOCs reaching the base boundary between 1984 and present, a short term sampling study in 1989 demonstrated higher concentrations of the same VOCs flowing through Outfall 003. Benzene, toluene and methylene chloride were detected at higher concentrations at the base boundary than during SPDES sampling. However, these chemicals were not detected downstream at Cliff Haven beach where people were most likely to have come into contact with the stream water.

Similarly, a study of the water quality in the Golf Course Drainage System was conducted in 1989-1990. VOCs were detected in the upstream water samples taken on the base. However, monthly sampling at the base boundary demonstrated that these chemicals were not reaching the base boundary or leaving the base in the stream water.

Public Health Implications

Both in the past and currently, people recreating at the Lake Champlain beach in Cliff Haven were not likely to experience adverse health effects from chemical contaminants originating from PAFB. Renewal of SPDES permits and sampling of the Golf Course Drainage Ditch Outfall-003 would identify slow on-base contaminant releases before levels of contaminants at the Cliff Haven Beach would present a public health hazard.

Because of community concerns about these chemicals migrating off-base to the Cliff Haven Community, ATSDR has evaluated the likelihood for people in the Cliff Haven Community to experience adverse health effects from their contact with the stream that runs off base, through their community, and to the beach at Lake Champlain. ATSDR estimated that people would be recreating in swim suits or shorts exposing the most skin to the environment during April through September for an average of 70 years. Exposure estimates are included in Appendix D.

The likelihood of resident exposure to chemicals in the stream was evaluated from the types and concentrations of chemicals detected in sampling conducted at Outfall-003. Prior to sampling of the Outfall-003, concentrations of contaminants were likely greater during peak activity at PAFB. ATSDR estimated exposure durations from types of recreational activities in which people likely participated, such as swimming, wadding, and incidental ingestion of surface water and sediments.

The low frequency of skin contact with contaminants in the stream, the low likelihood of accidental ingestion of the contaminants during swimming or wading activities at the beach, and low concentrations of pollutants, make health effects from exposures to the oil, grease, and detergents, pesticides and herbicides, solvents (VOCs), iron and sewage unlikely.

Potential for Future Exposure

Future sources of water to the golf course streams will likely include: (1) storm water runoff from the flightline (spill control dams and an aerator were installed in 1991-92 to address flightline discharges; (2) storm water runoff from the Golf Course; and (3) discharges of shallow groundwater to the stream system. Under the Base Reuse Plan for PAFB, the golf course will continue to operate and the runway and ramp areas are targeted for reuse as a civilian airfield. Routine sampling of the FT-002 groundwater contamination has identified a clay layer (lens) in the hydrogeologic structure near the flightline which has caused the contamination plume to loop around back toward the source area instead of flowing linearly toward stream C-19 and the base boundary. Only a small portion of the solvent and fuel contaminated shallow groundwater of the FT-002 groundwater operable unit is migrating east toward the base boundary even though some shallow groundwater in the golf course area discharges to the stream system ().

Deicing Fluids, Fuels:
When the flightline area is redeveloped as an airfield, the property owner will be required to develop a plan to minimize the potential for releases of aircraft and runway deicing fluids, fuels, and any hazardous substances to surface waters. Oversight of the implementation of such plans, referred to as a "Best Management Practices (BMP) plans, is conducted by the NYSDEC.

Solvents (VOCs):
Modeling of the VOC plume has been conducted as part of the FT-002 investigations. The modeling helps predict the future movement and ultimate extent of the plume based on several clean up scenarios for the shallow contaminated groundwater. AFBCA has predicted the extent of the plume by the year 2060 under four clean up scenarios: full (100%) removal of the source area contamination, and removal of 90%, 70%, and 50% of the source area contamination. Under conditions of 50%, 70%, and 90% source removal, the predicted plume extends into the golf course drainage area (23,24). Therefore, the amount of VOCs received by the drainage systems will increase in the future due to contamination currently in groundwater. The clay lens currently is acting as a wall retarding and blocking plume movement eastward toward the base boundary. Modeling of the groundwater contaminants predicts that contaminants from FT-002 will not migrate off base (23,24).

Discussions about final clean up plans are ongoing between NYSDEC, EPA, RAB members, and the public.

Conclusion and Public Health Action Plan for PAFB Flightline/Golf Course Drainage -
Exposure to Contaminated Surface Water (Off-base Cliff Haven Community)

4. No Apparent Public Health Hazard: Fire Training Area FT-002 - Exposure to Contaminated Groundwater and Possible Indoor Air Contamination (On-base Buildings)

Exposure of workers in the industrial corridor to fuel and solvent related contaminants (VOCs) in groundwater released to the surface and to contaminants released from groundwater to indoor air does not present a health hazard. Exposures would include direct contact with contaminated groundwater during digging and construction activities and breathing indoor air contaminated by the release of VOCs from groundwater up through soil and into air trapped in buildings. Contaminated shallow groundwater from the Fire Training Pit site (FT-002) and several other smaller sites at the PAFB is migrating east toward the industrial corridor. New buildings are being constructed to accommodate companies moving into the area. Construction activities such as digging may release contaminated shallow groundwater possibly exposing construction workers and employees who work in the buildings.

Background

From the 1950s until 1989, the base conducted fire fighter training activities in the area known as FT-002. During training exercises, jet fuel (not meeting specifications), waste oil mixtures, and spent solvents were poured into pits on the ground and ignited. Trainees practiced extinguishing the fires. As a result of the training exercises, the soil at the site was contaminated. Contamination migrated from the soil to the shallow groundwater. Floating contamination accumulated on top of the groundwater table. Additional subsurface soil adjacent to the pits became contaminated by contact with the floating product as the groundwater moved both horizontally, due to natural groundwater movement, and vertically because of groundwater level fluctuation (25).

There are four on-base areas which will most likely be impacted in the future by the FT-002 contamination in the future (25,26,27).

Area 1, FT-002 Source Area is currently open and unused. However, proposed future use includes light industrial, research and development, and warehousing with new building construction anticipated. Possible future human exposure would be by direct contact with contaminated groundwater or breathing contaminated air caused by off-gassing of groundwater contaminants to indoor air.

Area 2, Industrial Corridor, is currently open and used by tenants for industrial purposes. Future use could include industrial, commercial, and aviation support operations in existing, modified, or newly constructed buildings. Possible human exposure would be direct contact with contaminated groundwater or breathing contaminated air caused by off-gassing of groundwater contaminants to indoor air.

Area 3, Golf Course, will most likely remain in use as a pubic golf course. Possible human exposure would be direct contact with surface water in the Golf Course Drainage Ditch contaminated by groundwater migrating to surface water in the ditch/stream. The Golf Course Drainage Ditch becomes Stream C-19 at the base boundary and flows through the Cliff Haven Community to the beach area and into Lake Champlain.

Area 4, Weapons Storage Area Drainage, is currently open and unused. However, proposed future use includes industrial and aviation support with new building construction possible. Possible future human exposure would be by way of direct contact with surface water in the Weapons Storage Area Drainage Ditch contaminated by groundwater migrating to surface water in the ditch/stream.

Investigation and Clean up History

The information about groundwater and soil contamination comes from analysis of actual samples of groundwater, soil, soil gas, and surface water. Predictions using mathematical and spatial computer models were used to predict future groundwater and indoor air contamination. To assess the risks posed by the contaminated groundwater to public health and the environment, and to select a clean up strategy, the AFBCA is considering the groundwater impacts from these multiple sites as a base-wide groundwater issue referred to as the FT-002 Ground Water Operable Unit (25).

Groundwater monitoring wells have been sampled since the 1980s. An extensive area of shallow groundwater contamination exists at, and to the east of, the flightline area of the former base. The AFBCA has identified multiple areas which contribute to the contamination. Analysis of groundwater sampling information over time shows degradation of the contaminants. This is indicated by reduction of primary source contaminants and an increase of those chemicals that occur as a result of degradation.

Soil and soil gas samples have been collected since the 1980s and indicate several small source areas in addition to the fire training pits.

In 1993, remediation or clean up of the groundwater began with the pumping of the floating contamination product from the top of the groundwater table. Product recovery is ongoing and has recovered approximately 19,000 gallons of floating product to date (27).

In October 1996, remediation of the subsurface soil began with bioventing, a process which injects air into the subsurface to enhance the degrading of contaminants by natural biological processes. Additional soil remediation utilizes a process called soil vapor extraction that withdraws the volatiles (VOCs) out of the soil (27).

Indoor air sampling has been conducted on buildings most likely to accumulate off-gassing VOCs. Levels to date have not been found to present a health hazard to workers.

Contaminants which have been detected in the shallow groundwater include fuel components (benzene, toluene, ethylbenzene, xylenes) and chlorinated solvents (trichloroethylene, dichloroethylene, vinyl chloride)(25,26,27).

Table 5. No Apparent Public Health Hazard Situation - Exposure to Groundwater and Possible Indoor Air Contamination (On-base Buildings)

PATHWAY NAME	CONTAMINANTS	EXPOSURE PATHWAYS ELEMENTS					TIME	COMMENTS
		SOURCE	ENVIRONMENTAL MEDIA	POINT OF EXPOSURE	ROUTE OF EXPOSURE	EXPOSED POPULATION
PAFB groundwater contamination: potential impacts on surface water and indoor air quality	Multiple contaminants from multiple sites including: fuel components, lead, and chlorinated solvents	FT-002 Ground Water Operable Unit: this includes the shallow contaminated groundwater from multiple sources at the site that are moving east toward Lake Champlain FT-002; SS-004; SS-005; SS-006; SS-013; SS-017; SS-029; SS-011; LF-023; SS-008; SS-009; SS-035; SS-038	Shallow groundwater Soil gas to indoor air	New building construction sites Indoor air in buildings in the industrial area	Direct contact with the contaminated groundwater Inhalation of indoor air contaminated by fumes from the shallow groundwater contamination	Construction workers digging in contaminated area Employees in industrial area	Current Future Current Future	Modeling indicates no increased risk from exposure to contaminants. Remediation efforts to date and those planned for the future will likely cause reduction in the level of contaminants in which people can come in contact. Full disclosure and worker education further reduce the possibilitiy of exposure.

The plume of contamination currently is beneath the runway, airfield area, and industrial area. Contamination is discharging into the upper reaches of the golf course and weapons storage area drainage ditches, but is degrading or volatilizing to undetectable levels. Groundwater modeling predicted that the plume would extend further into groundwater beneath the industrial area and, ultimately, will discharge into the Golf Course and Weapons Area Drainage Ditches. Modeling also indicated that once in surface waters, contaminants would degrade or volatilize to nondetectable levels. At this time, the model has proven to be accurate.

Public Health Implications

ATSDR evaluated the likelihood of people to be exposed to groundwater contaminants at FT-002 in the following scenarios:

On-base Workers:

1) Contacting contaminated groundwater during new building construction, and 2) Breathing contaminated indoor air caused by off-gassing of contaminated FT-002 groundwater.

Exposure of construction workers to contaminated groundwater and exposure of employees to contaminated indoor air are the most likely exposures. AFBCA used computer modeling to predict the health risk to various groups of people exposed by various ways for two time periods: the present to 20 years and 20 to 40 years in the future. The modeling included conservative factors which would tend to overestimate exposure. The AFBCA estimated risks for all groups in each time period were below EPA's acceptable risk levels and therefore, do not indicate a health hazard for on-base workers.

Full disclosure of these possible hazards are included in the Finding of Suitability to Lease and Finding of Suitability to Transfer documents written by AFBCA with the oversight of EPA to PARC. In addition, past and future clean up efforts help reduce the possibility of current and future exposures. Exposure information is communicated to workers. Current VOC levels in indoor air have not been found to present a health hazard to employees working 40 hours per week. ATSDR concludes that direct contact with contaminants in groundwater and breathing indoor air do not present a health hazard for workers.

Conclusion and Public Health Action Plan for
Exposure to Groundwater and Possible Indoor Air Contamination (On-base Buildings)

1. No Public Health Hazard: Fire Training Area FT-002 - Exposure to Possible Groundwater Contamination (Off-base Private Wells)

Contaminated shallow groundwater from the Fire Training Pit site (FT-002) and several other smaller sites at the PAFB is migrating east toward Lake Champlain. The contamination has not migrated off base and therefore, no one off-base is currently being exposed. Plattsburgh residents who live between the base boundary and the lake rely on groundwater wells and surface water intakes for their household water supply. ATSDR considered if the water supplies of these residents could be impacted by the contamination at some time in the future. ATSDR concluded that the base groundwater contamination does not pose a public health hazard to off-base residents. This conclusion is based on the analysis of groundwater sampling data and groundwater migration modeling predictions by AFBCA. Using site-specific data on the chemicals, concentrations, and groundwater flow characteristics, and assuming at least partial removal of the contaminated source area contributing to the contamination, the modeling predicts that the groundwater chemicals will degrade in the environment before leaving the base.

Background

From the 1950s until 1989, the base conducted fire fighter training activities in the area known as FT-002. During training exercises, jet fuel (not meeting specifications), waste oil mixtures, and spent solvents were poured into pits on the ground and ignited. Trainees practiced extinguishing the fires. As a result of the training exercises, the soil at the site was contaminated. Contamination migrated from the soil to the shallow groundwater. Floating contamination accumulated on top of the groundwater table. Additional subsurface soil adjacent to the pits became contaminated by contact with the floating product as the groundwater moved both horizontally, due to natural groundwater movement, and vertically because of groundwater level fluctuation.

Investigation and Clean up History

The information about groundwater and soil contamination comes from analysis of actual samples of groundwater, soil, soil gas, and surface water. Predictions using mathematical and spatial computer models were used to predict future groundwater and indoor air contamination. See page 23-24 for details for FT-002 sampling and cleanup history (23,24).

The plume of contamination currently is beneath the runway, airfield area, and industrial area. Contamination is discharging into the upper reaches of the golf course and weapons storage area drainage ditches, but is degrading or volatilizing to undetectable levels. Groundwater modeling predicted that the plume would extend further into groundwater beneath the industrial area and, ultimately, will discharge into the Golf Course and Weapons Area Drainage Ditches. Modeling also indicated that once in surface waters, contaminants would degrade or volatilize to nondetectable levels (23,24). At this time, the model has proven to be accurate (28).

Table 6. No Public Health Hazard: Fire Training Area FT-002 - Exposure to Possible Groundwater Contamination (Off-base Private Wells)

PATHWAY NAME	CONTAMINANTS	EXPOSURE PATHWAYS ELEMENTS					TIME	COMMENTS
		SOURCE	ENVIRONMENTAL MEDIA	POINT OF EXPOSURE	ROUTE OF EXPOSURE	EXPOSED POPULATION
PAFB Groundwater contamination: potential impacts on the bedrock aquifer	Multiple contaminants from multiple sites including: fuel components, lead, chlorinated solvents, photographic development chemicals, oils, automotive batteries, ethylene glycol, and pesticides	FT-002 Ground Water Operable Unit: this includes the shallow contaminated groundwater from multiple sources at the site that are moving east toward Lake Champlain FT-002; SS-004; SS-005; SS-006; SS-013; SS-017; SS-029; SS-011; LF-023; SS-008; SS-009; SS-035; SS-038	Overburden (shallow) and bedrock aquifers	Residential taps in homes located south of Champlain Community college and east of the base that rely on well water drawn from the bedrock aquifer	Ingestion, direct contact, or inhalation (of vapors) of tap water derived from contaminated private wells that draw from the bedrock aquifer	People living in homes south of Champlain Community College and east of the base that rely on well water (approximately 105 people)	Future	Modeling indicates that the contaminants will not migrate off-base in the future. Monitoring of the line of sampling wells along the base boundary will permit early identification and action to address contaminants that could reach the base boundary in groundwater.

* Estimate based on number of map locations using well water. When the datum on the number of people served was not available for a particular map location, the number of people was estimated as 2.71 persons per household (1990 U.S. Census statistics for Census Tract 1016, Block Group 1, Clinton County). Three locations where the water source was unknown were assumed to rely on water wells for the purposes of these calculations.

Public Health Implications

ATSDR evaluated the likelihood of off-base residents drinking contaminated water caused by FT-002 groundwater contamination migrating off-base and affecting private well water or Lake Champlain surface water intake drinking water supplies.

The water supply sources for people living between the eastern boundary of the base and Lake Champlain could be well water, surface water intakes in the lake, or a public water supply. Generally speaking, the area north of, and including, the Champlain Community College is served by the Town of Plattsburgh public water supply. The Town of Plattsburgh obtains their water from deep water wells located in the hamlet of Morrisonville located 8 miles from PAFB. Areas south of the college are served by private wells which draw water from the bedrock groundwater resources. Homes that rely on surface water intakes are relatively few and are scattered along the shore of the lake (29).

The potential for the PAFB FT-002 groundwater contaminants to reach the private water supplies at some time in the future, at concentrations of health concern, was considered by ATSDR. The AFBCA is currently conducting a study to determine if the chemical contaminants will naturally break down in the environment (natural attenuation) to nonhazardous compounds, or if they might diminish to concentrations that do not pose a threat to human health and the environment, before the groundwater moves off base. Preliminary modeling of the future movement and breakdown of the contaminants in groundwater has been performed for different clean up scenarios. Using site-specific information about the chemicals, their concentrations, and groundwater flow at PAFB, the model indicates that contaminants will not migrate off-base in shallow groundwater in the future.

Groundwater from FT-002 is moving east toward Lake Champlain although information from current and future sampling and computer modeling indicate that off-base residents are not likely to be exposed to contaminated drinking water caused by FT-002.

NYSDOH requires a permit for any new well to be installed within one mile of PAFB. Educational information is given to well developers about the contamination detected at PAFB and suggests that well water be sampled prior to completion of the well development (29).

Conclusion and Public Health Action Plan for Fire Training Area FT-002 - Exposure to Possible Groundwater Contamination (Off-base Private Wells)

Conclusion: The FT-002 shallow contaminated groundwater plume at PAFB does not pose a threat to the health of people east of the base who rely on well and surface water supplies.

Completed and Ongoing Actions: NYSDOH requires new well developers to apply for a well digging permit in order to educate them about the potential for contamination. AFBCA has established a line of sentry wells along the eastern border of the base. Periodic sampling of these groundwater wells for contaminants will permit early identification of any contaminants that could migrate toward the base boundary and allow action to be taken to ensure that the contaminants do not affect off-base private water supplies. Continued monitoring of soil gas, groundwater, and surface water will help ensure that no one is exposed to levels of contaminants from FT-002 likely to cause adverse health effects. Clean up of chemicals at some of the waste ("source") areas are complete or ongoing. Reducing or eliminating the chemicals in the waste areas reduces the amount of chemicals available to move east in groundwater in the future.

Planned Action: Additional clean up and monitoring may be planed. Recommended Action: No additional actions are needed to ensure protection of public health.

2. No Public Health Hazard: Former Base Exchange Service Station ST-030 - Exposure to Possible Indoor Air Contamination (On-base)

The PAFB Base Reuse Plan identifies the unoccupied base housing at the intersection of Kentucky and Kansas Avenues for reuse in the future as a residential area. Currently, fuel-contaminated shallow groundwater from the BXSS site extends underneath some of the homes in the residential area. Soil gas and indoor air sampling conducted in April 1998 show that levels of contaminants pose no public health hazard to future residents of the New Base Housing Area.

Background

The site of the former Base Exchange Service Station (BXSS; ST-030 Site) is located at the intersection of Kansas Avenue and New York Road (Map 5). Constructed in 1958, the BXSS consisted of Building 2335, and several underground storage tanks (UST) (30). For a more complete history of gas stations activities see Table 8. The BXSS was operational from 1958 through 1994. Two schools built around 1959 are located within 500 yards of the BXSS site, but were not affected by the plume. Northside School is currently an active elementary school which is being used by the Peru School District. Southside School was used as middle school until it closed in June 1994. It is currently not being used.

Base residential housing is located 50 feet to the east and immediately down-gradient of the BXSS at the intersection of Kansas and Kentucky Avenues. A plume of shallow groundwater contamination from the BXSS site extends underneath the base housing area (31). Residents moved out of these homes in 1994 and 1995 as part of base closure. The homes remain unoccupied, but are designated in the PAFB Base Reuse Plan for redevelopment as a future residential complex. They were constructed in 1959 with "slab-on-grade" foundations. Concrete slab foundations over time and under seasonal temperature extremes develop cracks making it easier for shallow volatile groundwater contamination to migrate up through the soil into homes.

The depth to groundwater in this area of the base is shallow, with seasonal high water tables of only one to three feet below ground surface. In some areas the groundwater is seeping up to the ground surface between the homes. The shallow contamination under the residential area, combined with the old and potentially cracked slabs and foundations of these older homes, creates a potential pathway for the migration of gases from the fuel contamination to migrate into the homes. ATSDR evaluated inhalation by past and future residents of indoor air possibly contaminated with vapors from the contaminated groundwater.

Sampling and Clean up History

In 1990, leak tests conducted by the PAFB in conjunction with NYSDEC detected leaks in three 10,000 gallon USTs and a 550 gallon No. 2 fuel oil UST which were installed in 1958. Those tanks were removed and replaced with comparable sized double-walled USTs. The No. 2 fuel oil UST was replaced with a 275-gallon aboveground storage tank. The leaks prompted the base to begin an investigation which consisted of 4 monitoring wells, soil test pits, and a recovery well to capture petroleum product floating on the groundwater surface. The recovery system operated from May through September 1990 when free-floating product no longer appeared in the recovery well (30,31,32,33).

In 1992 the Air Force's Preliminary Assessment of the site found no visible evidence of contamination; but recommended further investigation to determine the effectiveness of earlier clean up efforts (30).

In April 1993, approximately 200 square feet of petroleum stained grass was discovered. NYSDEC Spill Response Team and base personnel dug test pits which revealed free floating product on the groundwater table. The 3000 gallon diesel UST and a 550 gallon waste oil UST were replaced with comparable sized double-walled USTs with leak detection and overfill protection devices (30).

Groundwater sampling was first conducted in 1990 when four monitoring wells were installed as part of the initial investigation of the site. They were removed in 1995 when excavation of the site began. Four new monitoring wells were installed in 1994 (MW-30-001 through MW-30-004). Three of the wells were downgradient of the BXSS and one upgradient. In the fall of 1995, two additional monitoring wells were installed (MW-30-005 and MW-30-006). One was installed in the heart of the plume and the other on the outer fringe. Monitoring well MW-30-007 was installed in August 1996 in the yard of building 7009, the closest downgradient home (30). In June 1997, MW-30-008 was installed far outside the leading edge of the plume. Ten additional wells (piezometers) were installed in April 2000; four were installed north and northeast of existing monitoring well MW-30-002. Three pairs (one shallow and one deep at each location) were installed surrounding existing monitoring well MW-30-001 (32,33).

Contaminants detected in groundwater include the volatile organic compounds benzene, ethylbenzene, toluene, xylenes, methyl tert-butyl ether (MTBE), dichloroethylene (DCE) and trichloroethylene (TCE). The semi-volatile organic compounds detected include naphthalene, phenol, and 4-methylphenol from automotive service activities (32).

In 1996, the BXSS was demolished and all tanks and associated piping were removed and properly disposed. The average depth of excavation around the tanks was 11 feet below surface. The entire site was also excavated to an average depth of four feet below surface. Approximately 2900 cubic yards of petroleum contaminated soil was removed and treated on base. Soil samples collected during and after the demolition and excavation confirmed that the source was removed (33).

Semiannual groundwater monitoring has been conducted since 1995 and will continue through 2001. Additional sampling projections may be revised to extend past the 2001 date. Trends in the sampling over time indicate that chemicals associated with fuels (benzene, toluene, ethylbenzene and xylenes) are decreasing. However, sampling from MW-30-002 indicates that the contamination plume may be expanding slightly in a northeasterly direction. To test this, additional wells (pieziometers) will be installed by the spring of 2000. The presence of low-levels (below drinking water standards) of non-fuel related VOCs such as TCE, and DCE are being detected in the upgradient well. This may indicate a slight backward flow of groundwater against the general groundwater flow pattern, or an additional unknown source of VOCs may have spilled upgradient of the BXSS. Additional wells will be installed near MW-30-001 by the spring of 2000 to help make this determination.

Risk-Based Corrective Action Evaluation
In 1997 and 1998, the AFBCA performed a Risk-Based Corrective Action (RBCA) evaluation of the potential for future inhalation of indoor air contaminated with BXSS soil gases to reach levels of health concern based on the maximum concentration of contaminants in groundwater. The RBCA is a mathematical model used to make predications about future events. RBCA analysis uses some site-specific information about the types and concentrations of chemicals in the groundwater, the depth to groundwater, the type of land use, and the integrity of building construction, and puts the information into a mathematical equation. Calculations are used to help predict if the highest levels of chemicals in the groundwater could result in people potentially being exposed to unsafe levels of chemicals in indoor air (33,34).

The RBCA evaluation conducted by AFBCA used the maximum concentrations of the chemicals detected in groundwater at the site and some default or non-site specific values which overestimate actual exposures in order to give a highly protective determination. From the available groundwater data, the draft report, issued in 1997, determined that levels of benzene and toluene could potentially migrate into soil and indoor air. Based on these conclusions, the Air Force conducted sampling of actual soil vapor and outside and indoor air (33,34).

Soil vapor and Indoor Air Sampling
In April 1998, soil vapor (4 samples) was collected from 2-3 feet below the ground surface around building 7009. Additionally, two indoor air samples were collected inside the unoccupied residence - building 7009 (one per floor) and one air sample collected outside the building (32). These samples were needed to determine if vapors from the groundwater had migrated up through the soil into homes. Sampling was conducted under several conditions that allow for higher volatile levels than would be considered actual conditions for human exposure: 1) sampling was conducted in an uninhabited home closed up with little to no airflow; 2) levels of contaminants present likely have been accumulating over time; and 3) sampling in warmer seasonal conditions would allow for greater release of volatile chemicals from groundwater. Despite the predisposition of the sampling conditions to elicit greater than normal volatile levels, sampling results of soil gas and indoor and outside air indicate that migration of vapors has not occurred because levels of contaminants present are not elevated. Therefore, contaminant levels present in air inside building 7009 do not present a public health hazard to either children or adults who would inhabit the home. Air sampling results being so similar, indicates a reliability of the air data.

Indoor air and soil vapor sampling conducted in 1998 indicates that levels of benzene and other chemical contaminants are not at levels that would present a health hazard to children or adults who would live in the homes near the former BXSS. The levels of contaminants present, are comparable to most homes in the United States and outside conditions. (35).

Groundwater Seeps
In the residential area, there are several places where the groundwater flows up to the surface of the ground. All of these areas are located well outside the plume area. Monitoring wells located outside the leading edges of the plume ensure that contaminants would not be present in seeps in the housing area before semiannual monitoring information would detect contaminant movement.

Figure 5. Former Base Exchange Service Station Area

Table 7. No Public Health Hazard: Former Base Exchange Service Station ST-030 - Exposure to Possible Indoor Air Contamination (On-base)

PATHWAY NAME	CONTAMINANTS	EXPOSURE PATHWAYS ELEMENTS					TIME	COMMENTS
		SOURCE	ENVIRONMENTAL MEDIA	POINT OF EXPOSURE	ROUTE OF EXPOSURE	POTENTIALLY EXPOSED POPULATION
Former Base Exchange Service Station ST-030 - Exposure to possible indoor air contamination (on-base)	Benzene, ethylbenzene, toluene, xylene, trichloroethylene, MTBE, and dichloroethylene	Underground storage tank releases, spills of gasoline, lubricants and oils	Groundwater Soil gas Groundwater seeps Surface soils	Indoor air Groundwater discharges in residential area	Inhalation of indoor air contaminated with vapors from the shallow groundwater contaminant plume Direct contact with seeping groundwater and ingestion of contaminated soils in seep area	People living in residential units east and north of the intersection of Kentucky and Kansas Streets and workers in future buildings on the BXSS site Children playing in the groundwater discharge area	Future Future	Soil gas and indoor air sampling conducted in April 1998 show that levels of contaminants pose no public health hazard to future residents of the New Base Housing Area. Currently, fuel-contaminated shallow groundwater from the BXSS site extends underneath some of the homes in the residential area. Sentry wells will provide early indication if contamination of seeps is likely.

Discussion and Public Health Implications

Although no one is currently living in the "New Base Housing" area, levels of contaminants present in air, soil gas, and groundwater do not present an inhalation health hazard to children or adults who could possibly live there in the future. Because contaminated soil has been removed and levels in groundwater are decreasing over time, levels of contaminants are not likely to increase in these home in the future.

Direct contact with, and incidental ingestion of, the contaminants by children playing in seep areas represents another way people can contact contaminants from the site. Although seep sampling data is not available, seeps are located in the housing areas well beyond the outer edges of contamination. Monitoring wells are sampled twice per year, permitting the early identification of any contaminants that may migrate toward the seeps and ample time to prevent any impacts on the water quality of the seeps and public health. Moreover, direct contact or even incidental ingestion with contaminants present at levels found in groundwater are not likely to cause adverse health effects in children who would play in the seeps.

Gasoline is made up of a combination of more than 150 different chemical components that, once released into the environment, begin to separate into distinct chemicals. Of greatest health consequence is benzene because of its implication in causing a specific cancer called acute myelocytic leukemia (35).

Since the 1970s, scientific and medical information has been collected from workers (male and female) exposed to gasoline from refineries, service stations, and high volume industrial fuel transfer operations. Additional information from sampling areas across the country provides a range of average, urban, and rural concentrations of several contaminants including benzene (35).

Because of the frequency and common exposure of people to gasoline, many studies have been done on exposure to gasoline and its individual components.

ATSDR has evaluated the likelihood of potential future exposures here to cause adverse health effects in children and adults breathing indoor air and children playing in seeps in the housing area. Benzene was detected in indoor air of Building 7009, the home closest to the contamination and most likely to have the highest levels. Benzene levels detected were 1.2 and 1.0 ug/m3. Toluene levels were 2.19 and 2.4 ug/m3. A review of the available scientific literature indicates that levels of benzene 100 times higher than those detected here have not been shown to cause adverse health effects. The No Observed Adverse Effect Level (NOAEL) for benzene was determined to be 100 ug/m3. Additionally, a review of the available scientific literature indicates that levels of toluene 50 times higher than those detected here have not been shown to cause adverse health effects. The NOAEL for toluene was 100 ug/m3 (36). Information about indoor air sampling across the country, shows levels of benzene and toluene in Building 7009 are not elevated and therefore, do not present a public health hazard.

Past Exposures
Although no indoor air sampling information is available from the time the BXSS was in service, it is reasonable to assume that contaminant levels in homes adjacent to the site was higher than the recent sampling levels.

Groundwater moves at a rate of roughly 2.1 ft/day in this area. (25) Fuel leaks from the BXSS are likely to have started long before they were actually detected in 1990. Therefore, people living in homes directly across from the BXSS may have inhaled higher levels of fuel-related contaminants than were detected during the 1998 sampling. Without sampling information, it is difficult to determine if levels would have presented a public health hazard in the past.

During the 1990s, several large-scale studies of benzene concentrations in air, food, and blood have added to our knowledge of its widespread presence in the environment. The new studies have confirmed earlier findings of the U.S. Environmental Protection studies and other large-scale studies in Germany and the Netherlands about the levels of human exposure and major sources. The new studies found that exposures people get through their everyday activities were higher than indoor concentrations of benzene. Additional information shows that indoor concentrations were generally higher than outdoor concentrations. The new studies of food concentrations also have confirmed earlier indications that food is not an important contributor for exposure to benzene. Major sources of exposure continue to be active and passive smoking, auto exhaust, and driving or riding in automobiles (37).

Future Reuse Plans
Current requirements for land reuse fall under the National Environmental Policy Act and involve the issuing of either "Finding of Suitability to Lease" (FOSL) or "Find of Suitability to Transfer" (FOST) based on an application issued from PARC to AFBCA. Both the FOSL and the FOST documents are written by the AFBCA with approval by the EPA. These documents include an evaluation of the environmental condition of the property and any deed restrictions or notification requirements.

Presently, the land formerly used as the BXSS and the homes located in the above the contaminant plume and many other homes surrounding this area (used as a buffer) are not included in those that are being considered for reuse or transfer. Although the RBCA and ATSDR's evaluation concluded that breathing indoor or outdoor air, touching or accidentally ingesting water from underground seeps do not pose a health hazard to future residents of the homes adjacent and downgradient of the former BXSS. AFBCA plans to retain these homes until the site closure is reached.

No one is currently living in "New Base Housing". However, the 1995 proposed reuse indicates a potential for the homes to be used in the future. Realistically, because the homes located in the 7000 block of "New Base Housing" have not been renovated to meet current housing code, the homes near the BXSS would not likely be inhabited in the future. Other on-base neighborhoods were renovated prior to base closure and would provide more homes than the projected housing market demands. Future land use could require demolition, new construction, and digging. Workers involved in these activities should be made aware of the past contamination so that they may employ safety practices such as personal protective equipment and perhaps field sampling for volatiles, including methane.

If either the existing homes are used or new homes are built over the contaminated groundwater, ATSDR recommends confirmatory sampling of indoor air and adjacent soil gas to help ensure that volatile chemicals migrating from groundwater do not pose a public health hazard. It should be noted that new housing materials contain detectable levels of volatiles that may confound sampling results.

Conclusion and Public Health Action Plan for
Former Base Exchange Service Station ST-030 - Exposure to Possible Indoor Air Contamination (On-base)

Table 8. History of Base Exchange Service Station (BXSS) Activities

Date	Activity
1958	BXSS Constructed (Building 2335, and several USTs). BXSS operated from 1958-1994 (36 years).
1963-1964	BXSS Expansion and Renovation (six 3,000-gallon USTs containing gasoline, one 3,000-gallon UST containing diesel, and one 550 gallon UST containing waste oil were added).
1983	Six 3,000-gallon USTs containing gasoline were abandoned in place with sand and concrete. Three 10,000 gallon fiberglass-coated plastic USTs were installed.
1990	All tanks leak tested. The three 10,000 gallon USTs and a 550 gallon No. 2 fuel oil UST (installed in 1958) failed. The No. 2 fuel oil and the 10,000 gallons were replaced with double-walled USTs. Those tanks were removed and replaced with a 275 gallon aboveground storage tank. The base began an investigation consisting of the installation of 4 monitoring wells, soil test pits, and a recovery well to capture petroleum product floating on the groundwater surface. The recovery system operated from May through September 1990 when free-floating product no longer appeared in the recovery well.
1992	The Preliminary Assessment of the site found no visible evidence of contamination, but recommended further investigation to determine the effectiveness of earlier clean-up efforts.
April 1993	Approximately 200 square feet of petroleum stained grass was discovered. NYSDEC Spill Response Team and base personnel dug test pits which revealed free floating product on the groundwater table. The 3000 gallon diesel UST and a 550 gallon waste oil UST were replaced with comparable sized double-walled USTs with leak detection and overfill protection devices.
November 1994	Four monitoring wells (MW-30-001 through MW-30-004) were installed downgradient of the BXSS.
September 1995	Approximately 485 cubic yards of petroleum contaminated soil was removed from 2 locations downgradient of BXSS. After completion, additional contamination was visibly present. Twenty-four soil samples were collected to define the extent of the contamination. Two additional monitoring wells were installed (MW-30-005 and MW-30-006).
December 1995 - May 1996	BXSS was demolished, all 11 USTs and associated piping were removed. Approximately 2900 cubic yards of contaminated soil was excavated (to an average depth of 11 feet) and placed on the flight line (land-farmed). Numerous soil and groundwater samples were collected. Monitoring well (MW-30-007) was installed in September at the southeast corner of Kansas Avenue and Kentucky Street.
June 1997	Geo-probe borings sampled unoccupied housing area downgradient of the site. Soil and groundwater samples were collected. Monitoring well (MW-30-008) was installed downgradient.
April 1998	Ambient air was collected inside and outside nearest unoccupied home (Building 7009) downgradient of BXSS. Soil vapor borings were collected.
To Date	Semiannual groundwater sampling have been performed since September 1995 (with the exception of fall 1997).

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