PUBLIC HEALTH ASSESSMENT
PASLEY SOLVENTS & CHEMICALS INC.
GARDEN CITY, NASSAU COUNTY, NEW YORK
A summary of the environmental contamination data collected duringthe RI for the Pasley site is presented in Appendix B, Tables 1-9. The listing of a contaminant does not necessarily mean that itspresence is a public health concern. Contaminants selected forfurther evaluation are identified and evaluated in subsequentsections of the public health assessment to determine whetherexposure to them has public health significance. When selected forfurther evaluation in one medium, that contaminant will be reportedin all media where it is detected. These contaminants are selectedand discussed based upon consideration of the following factors:
- Concentrations of contaminants on and off the site.
- Field data quality, laboratory data quality and sample design.
- Comparison of on-site and off-site concentrations with typical background concentrations.
- Comparison of contaminant concentrations in environmental media both on- and off-site with public health assessment comparison values for (1) noncarcinogenic endpoints and (2) carcinogenic endpoints. Contaminant concentrations above a comparison value do not necessarily represent a health threat but are evaluated further to determine if exposure is of public health significance. Comparison values include Environmental Media Evaluation Guides (EMEGs), Cancer Risk Evaluation Guides (CREGs), drinking water standards and other relevant guidelines.
- Community health concerns.
The most recent on-site environmental data for the Pasley site werecollected by the environmental engineering firm, Metcalf & Eddy ofNew York, Inc., under contract with Commander Oil Corporation, andwere presented in the final RI report. These data are used todescribe the nature and extent of contamination at the site on amedia-specific basis.
Air and Soil Gas
Ambient air has not been analyzed at the Pasley site. However,hand-held field instruments were used during the collection ofenvironmental samples and installation of monitoring wells inaccordance with health and safety protocol to monitor for organicvapors. Hydrocarbon odors were detected at the borehole openingsduring the installation of all seven on-site monitoring wells andwere also detected in soil boring samples. The highest organicvapor analyzer reading was 280 parts per million (ppm) from a soilsample collected at a depth of about 17 feet in soil boring 2. Thehighest photoionization detector (HNu) reading was greater than1,000 ppm at a depth of about 20 feet in the boring for the shallowon-site monitoring well 2S.
Soil gas was investigated in December 1988 by EA Engineering ofNewburgh, New York, a former consultant to Commander OilCorporation. Results of the on-site soil gas study are presentedin Table 4. Seventy-eight vapor samples were taken at forty-four locations. Nine of the sampling location points were on-site.
Six volatile organic compounds (VOCs) were targeted for analysesduring the survey. These target compounds were selected based onthe consultant's evaluation of historical information on the typesof products stored on-site and the VOCs previously found in soiland groundwater samples from the local area. The targeted VOCs arebenzene, toluene, ethylbenzene, o-xylene, trichloroethene (TCE) andtetrachloroethene (PCE). The sampling depths ranged from 3 to 20.5feet below grade. Multiple sampling locations were used tovertically profile vapor contaminant levels. On-site, the multiplesampling intervals generally were at 3, 8, 15.5 and 20.5 feet belowgrade. Five multiple sample locations were located on site.
The targeted VOC vapor analyses found TCE and PCE in the subsurfaceat several on-site locations. The highest on-site concentrationsof TCE and PCE vapors were in samples from the western portion ofthe site. TCE and PCE were detected at all sampling depthintervals of the on-site sampling locations except at the threefeet interval for a sample from the northeast corner of the site.
The targeted petroleum hydrocarbon VOCs (benzene, toluene,ethylbenzene, o-xylene) were found at two on-site locations at thewestern to southwestern portion of the Pasley site. Benzene wasnot detected at any on-site sampling location. Toluene was presentat four distinct depths with the highest concentration at a depthof 20.5 feet. Ethylbenzene/o-xylene were detected at only one on-site sampling location at a depth of 20.5 feet.
Surface soil samples were not collected during the RI.
Fifty soil samples were collected on the Pasley site at a depthbetween 6 to 12 inches and analyzed for VOCs, semi-volatile organiccompounds, and metals (see Figure 3 for locations). Backgroundsurface samples were not obtained during the RI. The laboratoryanalyses found elevated levels of VOCs, primarily solvents andpetroleum hydrocarbon compounds (see Tables 5 and 6). Twelve VOCsexceeded public health assessment comparison values and have beenselected for further evaluation.
Ten composite soil samples (6-12 inch depth) were analyzed forsemi-volatile organic compounds and metals. An additionalcomposite sample was collected for duplicate analysis. Compositesamples 1 and 4, collected on the western edge of the site,contained total semi-volatile compounds at levels of 56 and 88milligrams per kilogram (mg/kg), respectively. Composite samples8 and 9, collected on the eastern edge of the site, contained semi-volatile concentrations of 204 mg/kg and 127 mg/kg, respectively. The remaining composite samples, collected in the center of thesite, contained total semi-volatile compounds in the concentrationrange from 2 to 16 mg/kg. The predominant semi-volatile compoundswere polycyclic aromatic hydrocarbons (PAHs). Naphthalene andbenzo(a)pyrene exceed the public health assessment comparison valueand therefore will be further evaluated.
Antimony, lead, and magnesium were detected at levels which exceedcomparison values and as such have been selected for furtherevaluation.
Eight on-site subsurface soil borings were drilled and sampled atdepths of 12 to 14 feet and 22 to 24 feet (see Figure 4). Sixteensoil boring samples were analyzed for VOCs, semi-volatile organiccompounds and metals (see Table 6). Two additional samples werecollected for duplicate analysis. Organic compounds which exceedcomparison values are methylene chloride, trichloroethene,tetrachloroethene, 1,2-dichloroethane, naphthalene, and bis(2-ethylhexyl)phthalate. These compounds will be further evaluated. Metals were detected at levels below public health assessmentcomparison values.
Groundwater (Monitoring Wells)
Each of the six well clusters installed for the RI consist of 3monitoring wells. Each well cluster has one well screened at 30feet (shallow wells) and one well screened at 60 feet (intermediatewells) in the shallow (Glacial) aquifer. Each well cluster alsohas one well screened at 90 feet (deep wells) in the deeper (UpperMagothy) aquifer (see Figure 5). One well cluster (2S, 2I, 2D) isinstalled on-site. Groundwater was sampled twice. In February1990, the first round of samples were collected from each of theeighteen wells and analyzed for VOCs, semi-volatile compounds, andmetals. In April 1990, nine wells were sampled (three wellclusters) and analyzed for VOCs and semi-volatile compounds. Thewell data and comparison values are presented in Table 7.
The on-site groundwater contained thirteen VOCs (primarily solventsand petroleum hydrocarbon compounds) and two semi-volatilecompounds at concentrations exceeding comparison values. Thesecontaminants are acetone, 1,1-dichloroethene, 1,1-dichloroethane,trans-1,2-dichloroethene, ethylbenzene, tetrachloroethene, toluene,trichloroethene, benzene, 1,1,1-trichloroethane, chlorobenzene,xylenes (total), methylene chloride, 2-methylnaphthalene, andnaphthalene. These compounds have been selected for furtherevaluation in this public health assessment. The majority of VOCsand semi-volatile compound concentrations were highest in thesample from the shallow, on-site monitoring well. Trans-1,2-dichloroethene at 37,000 micrograms per liter (mcg/L) had thehighest overall concentration in this same well.
Cobalt, iron, lead, manganese, and sodium were detected ingroundwater samples from the on-site monitoring wells atconcentrations above the respective comparison values. Theseinorganic compounds will be further evaluated in the Public Health Implications section. Groundwater samples collected for metalsanalysis were not filtered.
Air and Soil Gas
Off-site ambient air analyses were not performed during the RI. However, 35 off-site locations were sampled during a soil gas studyconducted in December 1988 (results in Table 8). With theexception of two sampling locations, all off-site sampling pointswere located in the area south of Commercial Avenue, north ofLocust Street, west of Oak Street, and east of Boylston Street. The two remaining sampling locations were located just to the northof the site and south of the Long Island Railroad tracks. Thestudy was conducted on a 50 to 100 feet grid spacing. The soil gassamples were collected along four east to west transects:Commercial Avenue; Custer Park-Abandoned Railway; Brook Street-Brook Street extension; and Chestnut Street-Chestnut Streetextension. These transects were intended to be perpendicular togroundwater flow which is to the southwest. Six volatile organiccompounds were targeted for analyses; benzene, toluene,ethylbenzene, o-xylene, TCE and PCE. The sampling depths rangedfrom 3 to 20.5 feet below grade. Single sample locations generallywere conducted at 10.5 feet. Multiple sampling intervals were usedand were typically at 10.5, 15.5 and 20.5 feet below grade. Elevenmultiple sampling locations were off-site, 10 of which were locateddowngradient from the site.
The VOC vapor analyses showed TCE and PCE in the subsurface atseveral off-site locations. TCE and PCE were detected in a narrowplume area which extended in a south-southwest direction from thewestern half of the site toward Brook Street in the eastern end ofCuster Park. Beyond this area, TCE and PCE were not detected above1 ppm. The four targeted petroleum hydrocarbon VOCs were notdetected at any off-site sample location.
In August 1993, the NYS DOH and the NYS DEC investigated thepossibility that contaminants in soil gas may have had an impact onthe indoor air of two schools in the Garden City School District. The two schools evaluated were the Stewart Avenue and Locust StreetElementary, being in the general direction of groundwater flow fromthe Pasley Solvents and Chemicals site and other inactive hazardouswaste sites including the Roosevelt Field site. A third school,the Little Village school, was selected for comparison purposesbecause there is no known groundwater contamination in that area.
Five, four, and two soil gas samples were collected at a depth often feet at the Stewart Avenue, Locust Street, and Little Villageschools respectively, and were tested for chlorinated volatileorganic compounds and petroleum compounds. The soil gas sampleswere collected using a pneumatically driven Geoprobe and analyzedby a mobile laboratory situated outside the Stewart Avenue school. No compounds were found in these samples. On August 25, 1993, anambient air sample was collected outside the Locust Street schooland tested for the same organic compounds, none of which weredetected.
Surface Water and Sediments
A surface water sample was collected from one location within astorm water/recharge basin located about six city blocks south(downgradient) of the site. A sediment sample was also collecteddirectly below the surface water sampling location. The grabsample was collected using a hand auger and stainless steel scoop. Samples were analyzed for VOCs, semi-volatile organic compounds,metals, and cyanide. Tests of the recharge basin may not beindicative of contamination from the Pasley site since the basinserves a large drainage area including runoffs from streets.
Acetone was in both the surface water and the sediment sample at 42mcg/L and 0.02 mg/kg, respectively. Chlorobenzene and 1,1,1-trichloroethane were also detected in the sediment sample at 0.005mg/kg and 0.007 mg/kg, respectively. These VOCs did not exceedrespective comparison values.
Fourteen semi-volatile compounds were found in the sediment sampleat levels below comparison values; the concentrations ranging from0.09 mg/kg to 2 mg/kg. No semi-volatile compounds were detected inthe surface water sample.
Low concentrations of most inorganic compounds were found in thesurface water sample, except iron and manganese, which weredetected at 1,010 mcg/L and 426 mcg/L, respectively. Metals in thesediment sample were at concentrations near or below the typicalbackground level.
Surface soil samples were not collected at off-site locations.
Soil boring samples were collected from five off-site locations(see Figure 5). Two samples were collected from each of the fiveboring locations at depths between 5 to 11 feet. With theexception of methylene chloride at low concentration, no other VOCswere detected in any off-site borings (see Table 9). However, datafor several VOCs were determined to be unreliable and were notreported. Three semi-volatile compounds were detected in severalborings ranging from 0.07 mg/kg to 0.7 mg/kg. These organiccompounds did not exceed comparison values for soil.
With the exception of copper, the levels of metals in thesubsurface off-site soils were within the typical background range.
Groundwater (Monitoring Wells)
A total of five monitoring well clusters were installed off-siteduring the remedial investigation (see Figure 5). The off-sitegroundwater sampling results showed nine VOCs and two semi-volatilecompounds which exceeded comparison values (see Table 10). Theseorganic chemicals will be discussed further in subsequent sectionsof this public health assessment.
Eight metals were detected in off-site monitoring wells atconcentrations above comparison values. These inorganic chemicalswill be discussed further in subsequent sections of this publichealth assessment. Groundwater samples collected for metalsanalysis were not filtered.
Groundwater (Geoprobe Wells)
In August 1993, the NYS DOH and the NYS DEC investigated thepossibility that contaminants in groundwater may have had an impacton the indoor air of two schools in the Garden City SchoolDistrict. The two schools, Stewart Avenue and Locust StreetElementary, are in areas where, potentially, indoor air may beimpacted by groundwater contamination from the Pasley Solvents andChemicals site and other inactive hazardous waste sites. A thirdschool, the Little Village School, was selected for comparisonpurposes because no groundwater contamination has been found nearthis school.
Shallow (24.5 to 47 feet deep) and deep (62 feet deep) groundwatersamples were collected outside each school and tested forchlorinated volatile organic compounds and petroleum compounds. The groundwater samples were collected using a pneumatically drivenGeoprobe and analyzed by a mobile laboratory situated outside theStewart Avenue Elementary School. No chlorinated volatile organiccompounds or petroleum related compounds were found in the shallowgroundwater samples. One deep groundwater sample was taken at eachschool. No chemicals were found in either sample taken at theStewart Avenue or the Little Village School. The sample taken atthe Locust Street School contained several chlorinated volatileorganic compounds, namely, 1,1,1-trichloroethane, trichloroethene,tetrachloroethene, at 11 mcg/L, 4.1 mcg/L and 1.7 mcg/L,respectively.
Groundwater (Private Supply Wells)
According to the Nassau County Department of Public Works, privategroundwater wells are not used as drinking water supplies by homesand businesses in the area surrounding the site. However, private,industrial (non-potable) wells are used primarily to supply non-contact cooling water and were not sampled during the RI.
Groundwater (Public Supply Wells)
Potable water in the area surrounding the Pasley site is suppliedthrough public water supplies derived entirely from groundwaterwells (see Table 3). The RI did not include provisions forsampling public supply wells. However, information was obtainedfrom the NC DOH (Bureau of Public Water Supply) for downgradientwells less than about one mile from the Pasley site. The closestdowngradient public supply wells (well #8474 and #8475) are about1,600 feet southeast of the Pasley site. To date, monitoring hasnot detected any VOC contamination in well #8475. Since March1992, trichloroethene has consistently been detected in well #8474at concentrations ranging between 0.5 to 2 mcg/L. The Village ofHempstead's Clinton Street wellfield is about 3,800 feet southwestof the Pasley site and consists of seven production wellsidentified by the NC DOH as wells #79, 80, 81, 82, 83, 4425 and7298. To date, VOC contamination has not been detected in wells#80 and #82.
Tetrachloroethene (up to 86 mcg/L) and trichloroethene (up to 36mcg/L) were measured in municipal well #4425 from November 1977-December 1988. The well was taken out of service in September 1988and was not returned to service until October 1990 following theinstallation of an air stripper treatment system for removal ofVOCs. Wellhead samples taken from November 1977 to December 1989on well #83 contained tetrachloroethene (up to 15 mcg/L) andtrichloroethene (up to 145 mcg/L). Between 1978 and 1989, well #83was removed from service three times due to the presence oftrichloroethene above the NYS DOH guideline of 50 mcg/L in effectat the time for this compound in public drinking water supplies. Well #83 was last removed from service in January 1989. Eightsamples from well #7298 taken since 1977 have detected low levels(up to 2 mcg/L) of trichloroethene. Low levels (up to 2 mcg/L) oftetrachloroethene have also been detected in samples collectedbetween 1989 to date. Tetrachloroethene was not detected insamples collected from this well prior to 1989. This well iscurrently active and not treated. Well #79 is currently activewith no treatment. No VOCs were detected in well #79 prior to1989. From 1989 to date, tetrachloroethene and trichloroethenehave been detected in this well at concentrations up to 5.3 mcg/Land 1.5 mcg/L, respectively.
On September 9, 1993, dichlorodifluoromethane (freon-12) wasdetected in well #81 at 3.6 mcg/L. A resample taken on September15, 1993 also had dichlorodifluoromethane at 2.0 mcg/L. However,this compound was not detected when the well was retested onSeptember 23, 1993.
In preparing this public health assessment, NYS DOH relied on theinformation provided in the referenced documents and assumed thatadequate quality control measures were followed with regard tochain of custody, laboratory procedures, and data reporting. Theanalyses and conclusions in this public health assessment are validonly if the referenced information is correct.
No RI data were reported for the VOC, 2-butanone, as they wereregarded to be unreliable. As a result, the data were not completefor many soil samples, groundwater samples, and the surfacewater/sediment samples. In addition, data were not reported for asignificant number of off-site subsurface soil samples analyzed forVOCs due to the same reason.
First round groundwater analyses found acetone (up to 3,800 mcg/L)in samples obtained from on-site and off-site monitoring wells. These data are suspect because this compound (up to 2,300 mcg/L)was in the majority of the first round equipment blanks whichsuggests the possibility of laboratory contamination. Therefore,the acetone in the groundwater samples may not be indicative ofactual environmental contamination.
There are no known physical or other hazards present at the Pasleysite.
A search of the 1989 TRI facilities list was conducted to identifythose industries located near the Pasley Solvents and Chemicalssite (within 2.5 miles) which could contribute to groundwater,soil, or air contamination and/or create health threats unrelatedto the site. TRI is developed by the US EPA from the chemicalrelease (air, water, and soil) information provided by certainindustries. Using a screening method developed by the NYS DOH, twoTRI facilities were identified as reporting 1989 air emissions. These facilities are "Johnson & Hoffman", and "ContinentalExtrusion Corporation". These facilities are located north andnortheast of the site (Figure 6). These facilities did not reportemissions to water or soil. Johnson & Hoffman reported thefollowing releases to the environment via fugitive or non-point airemissions: trichloroethene - 15,000 pounds per year;tetrachloroethene - 6,500 pounds per year. The ContinentalExtrusion facility reported annual emissions (fugitive or non-point) of 1,1,1-trichloroethane at 30,000 pounds and 121,000 pounds stack or point air emissions. Based on TRI data and air emissionsmodeling, results of the screening evaluation indicate that thecontribution of these two industrial facilities to health risks inthe community around the Pasley Solvent and Chemicals site isminimal. Trichloroethene, tetrachloroethene, and 1,1,1-trichloroethane are, however, recognized as contaminants of concernat the Pasley Solvent and Chemicals, Inc. site and are evaluatedfurther in this public health assessment.
To determine whether nearby residents and persons on-site areexposed to contaminants migrating from the site, an evaluation wasmade of the environmental and human components that lead to humanexposure. The pathways analysis consists of five elements: asource of contamination, transport through an environmental medium,a point of exposure, a route of human exposure, and an exposedpopulation.
An exposure pathway is categorized as a completed or potentialexposure pathway if the exposure pathway cannot be eliminated. Acompleted exposure pathway occurs when the five elements of anexposure pathway link the contaminant source to a receptorpopulation. Should a completed exposure pathway exist in the past,present, or future, the population is considered exposed. Apotential exposure pathway exists when one or more of the fiveelements are missing, or if modeling is performed to replace realsampling data. Potential pathways indicate that exposure to acontaminant could have occurred in the past, could be occurringnow, or could occur in the future. An exposure pathway can beeliminated if at least one of the five elements is missing and willnever be present. The discussion that follows incorporates onlythose pathways that are important and relevant to the site.
Groundwater Exposure Pathway
Groundwater is contained in two water producing aquifers at thesite. The two aquifers are hydraulically connected. The shallowaquifer, which is referred to as the Upper Glacial aquifer, extendsfrom the surface to a depth of about 50 to 65 feet and consists ofsands and gravel. The saturated thickness of this aquifer at thesite is about 30 to 45 feet. Groundwater appears to flow southwestin this aquifer. Groundwater contamination in this aquifer hasbeen detected on-site, primarily from the 30 foot shallowmonitoring well.
The aquifer system underlying all of Long Island has beendesignated as a sole source aquifer since no other source ofdrinking water is available. There are four major water producingaquifer formations on Long Island. The two water producingaquifers underlying the site are the ones used most as sources forpotable water.
A number of public drinking water supply wells are within one miledowngradient from the site. The Magothy aquifer is the source ofgroundwater for all of these active and/or inactive supply wells. In the past, VOC contaminants have been detected in several ofthese wells, and in some instances, concentrations have exceededcomparison values. The Village of Hempstead Clinton StreetWellfield is located less than one mile southwest from the site. To date, VOC contamination has been detected in five wells at thiswellfield; two with levels above comparison values are beingtreated. For an undetermined period of time (more than 12 years),residents in the Village of Hempstead may have been exposed to lowlevels of volatile organic contaminants in drinking waterdistributed from the Clinton Street Wellfield. According toinformation included in US EPA's Draft Baseline Risk Assessment forthe Pasley site, the Clinton Street Wellfield is not within theboundary of the contamination plume from the Pasley site. The riskassessment also states that during transport, the chemical plume isexpected to sink from the Upper Glacial to the Upper Magothyaquifer, which is flowing in a more southerly direction thuschemical migration to the wellfield is not expected. Although thispast completed exposure pathway is not considered to be siterelated, it will be discussed further in the Public HealthImplications section.
VOC contaminants have also been detected in three other activewells located in the same wellfield. However, to date the levelsof VOCs have not exceeded NYS DOH drinking water standards. VOCcontamination has not been detected in the two remaining activesupply wells located in this wellfield. The Village of Hempsteadwells are not used individually but they all enter a commonreservoir which then feeds the distribution systems. Thisarrangement naturally provides some aeration which will removeportions of the VOCs and blending with other wells which willreduce any VOC levels. Blending is not allowed as a method toreduce such contamination and any wells exceeding drinking waterstandards individually are either removed from service or treated.
The VOC contaminants found in the aforementioned wells areprevalent throughout the groundwater in Nassau County. As such, itis only supposition to attribute the contamination to any specificsite. The RI suggests that other nearby sites may have contributedto the area's groundwater contamination. One of the sites isRoosevelt Field, a former airfield which is now occupied by a largeshopping mall. The Roosevelt Field contamination includes many ofthe same contaminants detected in the Pasley site monitoring wellsincluding the upgradient well cluster. In 1984, when groundwaterdata was collected in the area by the US Geological Survey, acontaminant plume in the upper glacial aquifer extended in excessof a mile south-southwest of the Roosevelt Field site.
The Purex/Mitchell Field Transit facility is the second majorgroundwater contamination source in the area, and is located about300 yards east of the Pasley site. VOC plumes attributed to thesite were found in the Upper Glacial, the Upper Magothy, and theLower Magothy aquifers. These investigations indicate thatgroundwater contamination has migrated from the Purex site into thePasley RI study area. On-going remediation work at the Purex siteincludes the operation of a groundwater extraction and treatmentplant for removal of VOCs.
Exposure to contaminants in drinking water supplies occur viaingestion; dermal contact and absorption during showering, bathing,or other household uses; and inhalation of aerosols and vapors fromwater used in the household. If site-related contaminants migrateto the active, downgradient public drinking water supply wells, theroutine monitoring that is mandated by New York State will detectcontamination. If contamination is detected, controls will beimplemented to minimize human exposures from occurring via thispotential exposure pathway.
Air and Soil Gas Exposure Pathway
All soils contain voids between solid particles which are eitherfilled with liquids (usually water) or gases. The gas that fillsthese voids is known as soil gas. Near the surface the soil gaswill be similar in makeup to surface ambient air includingassociated pollutants. Volatile organic contaminants in on-siteand off-site groundwater will tend to partition into the soil gasphase. Volatile components in the vapor phase will tend to migrateeither vertically or horizontally depending on localized soilconditions and confining layers. Elevated levels of VOCs in thesoils and shallow groundwater may contaminate ambient air on-siteand/or off-site depending upon the migration potential of the soilgas.
Ambient air was not sampled during the RI. However, an ambient airsample was collected in August 1993 outside the Locust StreetElementary School and did not indicate any VOC contamination.
Hydrocarbon odors and high readings were recorded on portable airmonitoring instruments places at the borehole during installationof the on-site monitoring wells. Elevated concentrations of TCEand PCE have been detected in the subsurface at several on-sitelocations and depths, primarily at the western portion of the site. These contaminants have also been detected in the subsurface atseveral off-site locations in a narrow plume area which extendssouth-southwest from the western half of the site. The groundwaterplume appears to extend under occupied commercial/industrialbuildings located near the site. Thus, the site contaminants couldmigrate off-site through porous media as soil gas and enterconfined spaces of buildings (basement) through crawl spaces,plumbing holes, other floor holes (e.g., sumps) and foundationcracks, and contaminate indoor air of rooms.
At this time, the air and soil gas exposure pathway is categorizedas a potential human exposure pathway since limited ambient airdata exists and recent soil gas data exists only for the three off-site schools. Contaminants released to ambient air (breathingzone) will likely be dispersed and diluted to levels belowdetection limits at unconfined on-site and off-site areas. However, the possibility exists for intrusion of soil gas intobasements of nearby buildings. Persons living or working in theseconfined areas may potentially be exposed to elevated levels ofsoil gas contaminants. Soil gas samples recently collected atthree Garden City schools were tested for chlorinated VOCs andpetroleum compounds. No compounds were found in the samples. Ifsoil gas is not contaminated, it cannot serve as a source foraffecting indoor air quality in the school buildings.
Soil Exposure Pathways
Contaminants related to the past storage and distribution ofchemicals at the site are present and are migrating through soilsand into the groundwater beneath the site. The surface andsubsurface soil serve as a continuing source of contamination tothe groundwater.
Because of the highly permeable soil materials (course sands andgravel) which exist beneath the site, many of the contaminants atthe site will readily move through the soil. The majority of thesite is covered with gravel which allows rainwater to percolatethrough the underlying soils and leach contaminants into thegroundwater.
On-site exposure to contaminated surface soils by trespassers isnot expected since site access is controlled by a chain link fencetopped with barbed wire and soils are beneath a gravel cover. Exposure to contaminated surface soil via wind transport of soildust is not likely due to the gravel cover material at the site.
Exposure to contaminated subsurface soils will not occur unlesssubsequent on-site excavation of soils is conducted. Futureexcavation of on-site soils could expose workers and nearbyresidents to contaminants via several routes including ingestion,inhalation and skin contact. Use of appropriate dust suppressionmethods, proper procedures, and air monitoring during clean-upwould minimize any low level increased risk to nearby workers andresidents.
The transport of contaminated soils to off-site areas via surfacewater runoff is a remote possibility. Extensive surface runofffrom the site is not expected based on the predominantly flattopography of the site and general lack of paved areas combinedwith the permeable on-site soils. These conditions would allowrainwater to infiltrate freely with limited restrictions ordiversions that typically cause surface runoff. Any surface waterrunoff from the site is directly routed into storm catch basinsalong Commercial Avenue. The runoff is eventually transported toa fenced recharge basin located about 2,200 feet southeast of thesite. This recharge basin is a pit that has been excavated intothe shallow aquifer deposits for infiltration. Water within thebasin infiltrates rapidly into the ground.
Based on past and current on-site conditions and controls, the soilexposure pathway may be eliminated from further discussion. Although soil contamination exists at the site, the possibility ofhuman contact with site related soil contaminants is remote givenexisting land use.
Surface Water/Sediment Exposure Pathway
This human exposure pathway has been eliminated from furtherdiscussion in this public health assessment since there are nosurface waters adjacent to the site. Access to the nearby stormwater recharge basin, which reportedly receives surface waterrunoff from the Pasley site, is controlled via a chainlink fence.
- Past and present ingestion, dermal and inhalation exposure tovolatile organic contaminants (VOCs) in municipal drinkingwater.
Historical monitoring of public water supply wells by theNassau County DOH indicates that for an undetermined period oftime (more than 12 years), residents in the Village ofHempstead may have been exposed to low levels of volatileorganic contaminants (VOCs) in drinking water. The Pasleysite does not appear to be the source of this contamination. New York State drinking water standards (effective in 1990)for tetrachloroethene and trichloroethene are 5 mcg/L. Chronic exposure to chemicals in drinking water are possibleby ingestion, dermal and inhalation exposures from water usessuch as showering, bathing and cooking. Although exposuresvary depending on individual life-styles, each of theseexposure routes contributes to the overall intake and thusincreases the potential for chronic health effects.
Tetrachloroethene and trichloroethene cause cancer inlaboratory animals exposed to high levels over their lifetimes(ATSDR, 1989i, 1990e). Chemicals that cause cancer inlaboratory animals may also increase the risk of cancer inhumans who are exposed to lower levels over long periods oftime. Whether or not tetrachloroethene and trichloroethenecause cancer in humans is not known. Based on the results ofanimal studies and the sampling results for municipal wellwater, we estimate the persons previously exposed tocontaminated public drinking water may have a low increasedrisk of developing cancer over a lifetime of exposure. Givendistribution practices (mixing of water supply wells), currentexposure to low levels of tetrachloroethene would beassociated with a very low increased cancer risk over alifetime of exposure.
Tetrachloroethene and trichloroethene also produce a varietyof noncarcinogenic toxicities (primarily nervous system, liverand kidney effects) at exposures many orders of magnitudegreater than current or past exposure from municipal drinkingwater. Chemicals that cause effects in humans and/or animalsafter high levels of exposure may also pose a risk to humanswho are exposed to lower levels over long periods of time. Although the risks of noncarcinogenic health effects from pastor current exposures aren't completely understood, theexisting data suggest that they are minimal.
- Potential ingestion, dermal and inhalation exposure tocontaminants in municipal drinking water as a result ofcontaminant plume migration.
On-site and off-site groundwater is contaminated with volatileand semi-volatile organic compounds and metals atconcentrations which exceed comparison values (see Table 10). Although the Pasley site contaminant plume is not expected tomigrate in the direction of the nearby wellfield, thepossibility of potential impacts on municipal drinking waterin the future cannot be completely discounted.
Volatile Organic Compounds
Benzene is a known human carcinogen (ATSDR, 1989a). Chlorobenzene, 1,1-dichloroethane, 1,1-dichloroethene,methylene chloride, tetrachloroethene, and trichloroethenecause cancer in laboratory animals exposed to high levels overtheir lifetimes (ATSDR, 1989b,e,g,i; 1990 a,e). Whether ornot they cause cancer in humans is not known. Chemicals thatcause cancer in laboratory animals may also increase the riskof cancer in humans who are exposed at lower levels over longperiods. Exposure to these organic contaminants in drinkingwater at the levels found in on-site and/or off-sitegroundwater could pose a high increased cancer risk. Toxicological data are inadequate to assess the carcinogenicpotential of trans-1,2-dichloroethene, ethylbenzene, toluene,1,1,1-trichloroethane, xylenes and acetone (ATSDR, 1989f,h,1990b,f,g; US EPA, 1991).
These volatile organic compounds are also known to produce avariety of noncarcinogenic toxicities (primarily liver,kidney, nervous system, and cardiovascular effects, and in thecase of benzene, damage to blood-cell forming tissue andimmune system) at exposure generally several orders ofmagnitude greater than potential exposures from on/or off-sitegroundwater. Chemicals that cause effects in humans and/oranimals after high levels of exposure may also pose a risk tohumans who are exposed to lower levels over long periods oftime. Although the risks of noncarcinogenic health effectsfrom potential exposure to VOC's in drinking water at levelsfound in on-site and off-site groundwater aren't completelyunderstood, the existing data suggest that they could be highfor benzene and trans-1,2-dichloroethene and low for acetone,chlorobenzene, 1,1,1-trichloroethane and trichloroethene.
Semi-Volatile Organic Compounds
Bis(2-ethylhexyl)phthalate causes cancer in laboratory animalsexposed to high levels over their lifetimes (ATSDR, 1991b). Exposure to this organic contaminant in drinking water at thelevel found in off-site groundwater could pose a low increasedcancer risk. Toxicological data are inadequate to assess thecarcinogenic potential of 2-methylnaphthalene and naphthalene(ATSDR, 1990d). Bis(2-ethylhexyl)phthalate can also adverselyaffect the male reproductive system, whereas 2-methyl-naphthalene and naphthalene can cause hemolytic anemia andliver damage. These compounds produce their noncarcinogeniceffects at exposure levels many orders of magnitude greaterthan potential exposures from groundwater. Existing datasuggest that the risks of noncarcinogenic health effects fromexposure to these three chemicals in drinking water at levelsfound in on-site or off-site groundwater would be minimal.
Metal contaminants of potential concern in on-site and/or off-site groundwater include lead, antimony, beryllium, chromium,cobalt, manganese, nickel, iron and sodium. Chronic exposureto elevated lead levels is predominantly associated withneurological and hematological effects (ATSDR, 1991c). Thedeveloping fetus and young children are particularly sensitiveto lead-induced neurological effects (ATSDR, 1991c). Theprimary toxicities associated with ingestion of large amountsof antimony are lung and heart damage (ATSDR, 1990h). Ingestion by experimental animals of elevated levels ofberyllium has been associated with lung damage (ATSDR, 1991a). The primary toxicities associated with ingestion of largeamounts of chromium have been kidney damage, birth defects andadverse effects on the reproductive system (ATSDR, 1989d). The primary adverse effect associated with exposure toelevated levels of cobalt is heart damage (ATSDR, 1990i). Exposure to high manganese concentrations primarily causesnervous system damage (ATSDR, 1990c). Gastrointestinal,hematological and cardiovascular systems in humans may betargets of toxicity after ingestion of high concentrations ofnickel (ATSDR, 1991d). Although iron is an essentialnutrient, ingestion of large amounts can lead to accumulationin the body and tissue damage. Its presence in drinkingwater, however, is objectionable primarily due to its affecton taste and staining of laundry and plumbing fixtures. Likeiron, elevated levels of manganese in drinking water adverselyaffect taste and cause staining of clothes and plumbingfixtures. The levels of manganese (up to 16 mg/L) in on-sitegroundwater and iron (up to 152 mg/L) in off-site groundwaterare more than 150 and 300 times, respectively, the levels atwhich the aesthetic quality of drinking water begins to beaffected (WHO, 1984) and would render drinking waterunpalatable. Sodium was found in on-site groundwater atlevels up to 390 mg/L. Water containing more than 20 mg/L ofsodium should not be used for drinking by people on severelyrestricted diets and water containing more than 270 mg/L ofsodium should not be used for drinking by people on moderatelyrestricted diets.
Chronic exposure to drinking water contaminated with lead atconcentrations found in off-site groundwater could pose amoderate increased risk of adverse health effects. The healtheffects from antimony, cobalt, chromium and manganese could below and for exposure to beryllium and nickel would be minimal.
If site-related contaminants migrate to the active,downgradient public drinking water supply wells, the publichealth implications summarized above would be minimizedbecause the routine monitoring mandated by New York State willprovide for early detection and implementation of controls tominimize human exposures.
- Potential inhalation exposure to volatile organic compounds inindoor air due to migration of soil vapors into nearbystructures.
Sufficient data are not available to adequately assess thispotential exposure pathway. Volatile organic compounds have,however, been detected in several on-site and off-site soilgas samples at levels that could pose a significant healththreat if nearby buildings are impacted. Levels oftrichloroethene (as high as 400 ppm), tetrachloroethene (ashigh as 140 ppm), toluene (as high as 1,000 ppm), andethylbenzene and xylene (as high as 800 ppm) on-site are inthe range of levels known to damage the nervous system aftereven short-term exposure. The results of recent soil gastesting at the downgradient Locust Street Elementary Schoolindicate that there does not exist the threat for indoor aircontamination within the school building.
The NYS DOH has not evaluated health outcome data for the Pasleysite or the Town of Hempstead. For an undetermined period of time(more than 12 years), residents in the Town of Hempstead may havebeen exposed to low levels of volatile organic compounds (VOCs) indrinking water. Because the health risks from these exposures arelow for both cancer and non-cancer endpoints, the possibility ofdetecting any effect is very small. Therefore, these data baseswill not be searched at this time. In 1990, the NYS DOH reportedon breast cancer incidence rates for small geographic areas ofNassau and Suffolk Counties for the years 1978-1987. Therelationship between breast cancer incidence and contaminateddrinking water wells and hazardous waste sites was also examined. Variations were seen in breast cancer incidence rates among smallgeographic areas in these counties. A relationship was observedbetween high breast cancer incidence and high levels of householdincome. No association was found between breast cancer incidencepatterns and contaminated drinking water wells or hazardous wastesites.