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PUBLIC HEALTH ASSESSMENT

DELILAH ROAD
EGG HARBOR TOWNSHIP, ATLANTIC COUNTY, NEW JERSEY


ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS

The tables in this section list the contaminants of concern for the Pomona Oaks Wells site. These contaminants are evaluated in subsequent sections of the Public Health Assessment to determine whether exposure to them has public health significance. ATSDR selects and discusses these contaminants based upon the following factors:

    1) Concentrations of contaminants on and off site.

    2) Field data quality, laboratory data quality, and sample design.

    3) Comparison of on-site and off-site concentrations with background concentrations, if available.

    4) Comparison of on-site and off-site concentrations with health assessment comparison values for carcinogenic and noncarcinogenic endpoints.

    5) Community Health concerns.

In the data tables that follow under the On-site Contamination subsection and the Off-site Contamination subsection, the listed contaminant does not mean that it will cause adverse health effects from exposures. Instead, the list indicates which contaminants will be evaluated further in the Public Health Assessment. When selected as a contaminant of concern in one medium, that contaminant will be reported in all media.

The data table may include one or more of the following acronyms:

    * CREG = ATSDR Cancer Risk Evaluation Guide
    * EMEG = ATSDR Environmental Media Evaluation Guide
    * MCLG = EPA Maximum Contaminant Level Goal
    * MCL = EPA Maximum Contaminant Level
    * PMCLG = EPA Proposed Maximum Contaminant Level Goal
    * ppm = Parts per million
    * ppb = Parts per billion
    * RfD = EPA Reference Dose
    * RfC = EPA Reference Concentration

Comparison values for public health assessments are contaminant concentrations in specific media that are used to select contaminants for further evaluation. These values include Environmental Media Evaluation Guides (EMEGs), Cancer Risk Evaluation Guides (CREGs), and other relevant guidelines. CREGs are estimated contaminant concentrations based on a one excess cancer in a million persons exposed over a lifetime. CREGs are calculated from USEPA's cancer slope factors. USEPA's Maximum Contaminant Level Goal (MCLG) ia a drinking water health goal. USEPA believes that the MCLG represents a level that no known or anticipated adverse effect on the health of persons should occur which allows an adequate margin of safety. Proposed Maximum Contaminant Level Goals (PMCLGs) are MCLGs which are being proposed. Maximum Contaminant Levels (MCLs) represent contaminant concentrations that USEPA deems protective of public health (considering the availability and economics of water treatment technology) over a lifetime of 70 years at an exposure rate of 2 liters of water per day. While MCLs are regulatory concentrations, PMCLGs and MCLGs are not. USEPA's reference dose (RfD) and Reference Concentration (RfC) are estimates of the daily exposure to a contaminant that is unlikely to cause health effects.

To identify possible facilities that could contribute to contamination of environmental media near the Delilah Road Landfill site, the ATSDR and the NJDOH searched the 1987, 1988, and 1989 Toxic Chemical Release Inventory (TRI). TRI is developed by the USEPA from chemical release (air, water, and soil) information provided by certain industries. Upon review and evaluation, TRI was not found to contain information on toxic chemical release in Egg Harbor Township which was pertinent to the contaminants and pathways of concern at the Delilah Road Landfill site.

Phase I and Phase II investigations (CDM; August 1989) of the Delilah Road Landfill provided data describing on-site soil quality (test pit excavations), on-site and off-site groundwater quality, and off-site surface water and sediments (Jarrets Run). Investigation of other environmental media were not conducted as part of the RI/FS process.

A. On-Site Contamination

    Soils

During the RI/FS, site soils were characterized through test pit excavations to determine the composition of the material within the landfill, determine the nature and extent of potential chemical contamination, and to verify results of magnetometer surveys. Municipal waste is the primary material deposited within the landfill, although paving and construction debris was also found. Information regarding the depth at which specific samples were taken was not available. The western portion of the landfill contains evidence of sludge deposition. This area contained several inorganics in excess of NJDEPE action levels; arsenic (866 ppm), barium (719 ppm), beryllium (5.4 ppm), and selenium (11.8 ppm). Of these, arsenic is above the ATSDR comparison value of 210 ppm (based upon Rfd) for an adult. Several volatile and semivolatile compounds were detected in test pit samples but these were all below NJDEPE action levels and ATSDR comparison values (adult RfD).

    Groundwater

During Phase I and Phase II investigations a total of sixteen monitoring wells were installed in and around the landfill (figures 3 and 4). One on-site well, DEL-B, exhibited benzene (4 ppb) in excess of the ATSDR CREG for the compound (1.2 ppb). Table 1 presents a summary of contaminants of concern present in groundwater at the Delilah Road Landfill.

Table 1 - Groundwater Contamination; Contaminants of Concern, Delilah Road Landfill, Egg Harbor Twp., N.J.

                   Values Are Maximum Reported Concentrations.


Monitor Wells
Potable Wells
Comparison Value
Contaminant
ppb
Well
ppb
Well
ppb
Source
Tetrachloroethene
11
MW6-100
5
PO-25
5
MCL
Benzene
4
DEL-B
12
PO-25
1.2
CREG
Vinyl Chloride
ND
-
9
PO-25
0.7
EMEG
Mercury (metallic)
NA*
-
5
PO-7
2
MCL
Lead
153
MW3-40
46.4
PO-5
0
MCLG
Cadmium
NA*
-
9.5
PO-3
2
EMEG
    * = Data rejected; holding times exceeded.
    ND = Not Detected
    MCL = EPA Maximum Contaminant Level
    MCLG = EPA Maximum Contaminant Level Goal
    CREG = ATSDR Cancer Risk Evaluation Guide
    EMEG = ATSDR Environmental Media Evaluation Guide

Data from Phase I and Phase II Remedial Investigation Report, CDM: August 1989.

B. Off-Site Contamination

    Sediments

Sediment samples of Jarrets Run were taken at two locations to determine if the site had impacted this intermittent stream (figure 5). Results indicated the presence of polynuclear aromatic hydrocarbons, none of which exceeded ATSDR screening values. However, although surface water run-off from the landfill might enter the stream as a result of heavy precipitation or flood conditions, the contaminants detected are reported to likely be products of combustion and/or highway runoff, and not related to the landfill.

    Surface Water

Water samples from Jarrets Run were analyzed as part of the Phase I RI/FS process for the site (figure 5). Results showed no organic or inorganic contaminants in excess of ATSDR comparison values.

    Ground Water

Off site groundwater data were provided by numerous monitoring and private potable wells in the proximity of the landfill (figures 3 and 4). Ground water in the area is moving to the southeast. Monitoring well MW6-100 (tetrachloroethene; 11 ppb) and MW3-40 (lead; 153 ppb) exhibited contaminants exceeding ATSDR comparison values. One potable well (PO-25) exhibited tetrachloroethene (5 ppb), benzene (12 ppb), and vinyl chloride (9 ppb) at levels exceeding ATSDR comparison values. Two other potable wells exhibited one contaminant in excess of ATSDR comparison values: PO-7 (mercury; 5 ppb), and PO-3 (cadmium; 9.5 ppb). Additionally, one potable well (PO-5) contained lead (46.4 ppb) at a level slightly below the ATSDR comparison value of 50 ppb. Table 1 contains a summary of off-site groundwater contaminants of concern.

C. Quality Assurance And Quality Control

In preparing this public health assessment, the ATSDR and the NJDOH rely on the information provided in the referenced documents and assume that adequate quality control measures were followed with regard to chain-of-custody, laboratory procedures, and data reporting. The validity of analysis and conclusions drawn for this health assessment is determined by the availability and reliability of the referenced information.

D. Physical And Other Hazards

The Delilah Road Landfill contains abundant debris which represent potential hazards to trespassers, particularly children. The remains of past illegal dumping, old appliances, furniture, and other materials represent a potential for physical injury.

Based upon available data, the Delilah Road Landfill does not present any radiological or biological hazards.


PATHWAYS ANALYSIS

To determine whether nearby residents are exposed to contaminants migrating from the site, ATSDR and NJDOH evaluate the environmental and human components that lead to human exposure. This pathways analysis consists of five elements: (1) a source of contamination; transport through an environmental medium; (3) a point of human exposure; (4) a route of human exposure; and, (5) an exposed population.

ATSDR and NJDOH classify exposure pathways into three groups: (1) completed pathways (those in which exposure has occurred, is occurring, or will occur; (2) potential pathways (those in which exposure might have occurred, may be occurring, or may yet occur; and, (3) eliminated pathways (those that can be eliminated from further analysis because one of the five elements is missing and will never be present, or in which no contaminants of concern can be identified.

A. Completed Exposure Pathways

Completed exposure pathways at the Delilah Road Landfill are associated with the ingestion of contaminated ground water prior to the availability of municipal water supplies in 1989. Landfilling operations at the site began in 1972. There are no data or information to indicate when the onset of groundwater contamination occurred, but the proximity of shallow potable wells to the site, together with the deposition of fill materials at or below the water table suggest a rapid transport of contaminants. Wells to the southeast (PO's 3,5,7, & 25; figure 3 & 4) are directly downgradient of the landfill and were impacted by site-related contaminants. Ingestion of groundwater (for a maximum period of 17 years) is the primary completed exposure pathway at the site, although secondary pathways associated with non-potable domestic water usage may have existed. Table 2 summarizes the completed exposure pathway elements at the Delilah Road Landfill site.


Table 2 - Completed Exposure Pathways; Delilah Road Landfill, Egg Harbor Twp., N.J.

Pathway
Name

Exposure Pathway Elements
Time
Source
Media
Point Of
Exposure
Route Of
Exposure
Exposed
Population
Potable
Water
DRL*
Ground
Water
Residence
Ingestion
Residents
Past
    * = Delilah Road Landfill

B. Potential Exposure Pathways

Potential exposure pathways at the Delilah Road Landfill are associated with on site soils and air. Limited soil data (test pit excavations) have suggested that areas of the landfill contain inorganics (arsenic) in excess of ATSDR comparison values. Other areas of the site may harbor undocumented hotspots of metals and other compounds. As it is known the landfill and adjacent areas are utilized for recreational purposes, and are presently unsecured, a potential exposure pathway exists for on-site trespassers. Activities such as operating trail motorcycles and other vehicles may generate dust from contaminated soils and result in the respiration or ingestion of contaminants.

Although not documented in existing site data, it is expected that the Delilah Road Landfill generates methane gas as the byproduct of waste decomposition. Methane gas, if present in sufficient concentration and under changing atmospheric conditions, represents a potential hazard to persons on-site through asphyxiation and explosivity.

Table 3 summarizes the elements of the potential exposure pathways at the Delilah Road Landfill Site.

Table 3 - Potential Exposure Pathways; Delilah Road Landfill, Egg Harbor Twp., N.J.

Pathway
Name
Exposure Pathway Elements
Time
Source Media Point Of
Exposure
Route Of
Exposure
Exposed
Population
Dusts DEL* Soils Landfill Inhalation
Ingestion
On-Site
Trespassers
Past
Present
Future
Methane DEL* Air Landfill Inhalation On-Site
Trespassers
Past
Present
Future
    * = Delilah Road Landfill

PUBLIC HEALTH IMPLICATIONS

A. Toxicological Evaluation

This section discusses the potential for health effects in persons exposed to specific contaminants, evaluate state and local databases, and address specific community health concerns. Health effects evaluations are accomplished by estimating the amount (or dose) of those contaminants that a person might come in contact with on a daily basis. This estimated exposure dose is than compared to established health guidelines. People who are exposed for some crucial length of time to contaminants of concern at levels above established guidelines are more likely to have associated illnesses or disease.

Health guidelines are developed for contaminants commonly found at hazardous waste sites. Examples of health guidelines are the ATSDRs Minimum Risk Level (MRL) and the USEPAs Reference Dose (RfD). When exposure (or dose) is below the MRL or RfD than non-cancer, adverse health effects are unlikely to occur.

MRLs are developed for each route of exposure, such as acute (less than 14 days), intermediate (15 to 364 days), and chronic (365 days and greater). ATSDR presents these MRLs in Toxicological Profiles. These chemical-specific profiles provide information on health effects, environmental transport, human exposure, and regulatory status.

The toxicological evaluation of the completed exposure pathway at the Delilah Road Landfill is based upon a duration of seventeen (17) years for the ingestion pathway. As it is impossible to accurately determine when groundwater at the site first exhibited contamination above health based criteria, the use of a 17 year exposure duration represents the time from the onset of the earliest known landfilling operations at the site (1972) to the availability of a public water supply (1989). Additionally, groundwater in the area of the site contains contaminants (particularly metals) which are not site related and may have been present before the onset of landfilling operations at the site.

The toxicological effects of the contaminants detected in potable wells at the Delilah Road Landfill site have been considered singly. The cumulative or synergistic effects of possible mixtures of contaminants may serve to enhance their public health significance. Additionally, individual or mixtures of contaminants may have the ability to produce greater adverse health effects in children as compared to adults. This situation depends upon the specific chemical being ingested, its pharmacokinetics in children and adults, and its toxicity in children and adults.

Non-potable domestic usage of contaminated water (showers, washing machines) may be associated with significant exposure through the inhalation and dermal contact routes. Current literature suggests exposure doses from these routes may approach those associated with direct ingestion (Reference 12). Although there exist no data to describe these secondary routes of exposure at he Delilah Road Landfill site, this toxicological discussion recognizes their potential contribution to exposure dose estimates and consequent public health implications.

    Tetrachloroethylene

Site data indicate that exposure to tetrachloroethylene occurred among residents in the area of the Delilah Road Landfill through the ingestion pathway. For a period of approximately 17 years, three households were exposed daily to low doses of tetrachloroethylene by using contaminated groundwater for drinking and other domestic purposes. Exposure doses assessment assumes that adults drink on the average of two liters of well water per day, and children drink one liter of well water per day.

Based upon maximum levels of tetrachloroethylene detected in potable wells at the site, exposure doses were below the USEPA oral RfD of 0.01 mg/kg/day. Calculated exposure dosages are well below the Minimum Risk Level (MRL) for chronic oral exposure represented in the ATSDR Toxicological Profile for Tetrachloroethylene. At such concentrations, it is not likely that adverse health effects would occur.

Tetrachloroethylene is considered by the USEPA to be a probable human carcinogen based upon evidence from animal studies. There is no current oral carcinogenic slope factor from which to calculate a Lifetime Excess Cancer Risk (LECR) value for tetrachloroethylene exposure at the site. However, exposure doses based upon maximum detected concentrations of the compound are well below the Cancer Effect Levels for animals represented in the ATSDR Toxicological Profile for tetrachloroethylene. At such concentrations it is unlikely that any increased cancer risk would result.

    Benzene

Site data indicate that exposure to benzene occurred among residents in the area of the Delilah Road landfill through the ingestion pathway. For a period of approximately 17 years, two households were exposed daily to low doses of benzene by using contaminated groundwater for drinking and other domestic purposes. Exposure dose assessment assumes that adults drink on the average of two liters of well water per day while children drink one liter of well water per day.

Presently there is no MRL or RfD for chronic oral exposure to benzene. However, exposure doses calculated from the maximum reported levels of benzene at the site were below the No Observed Adverse Effect Level (NOAEL) for animal studies presented in the ATSDR Toxicological Profile for Benzene. At such concentrations, it is not likely that non-carcinogenic adverse health effects would occur.

Benzene is considered by the USEPA to be a known human carcinogen. The maximum reported concentration of benzene in well water exceeded ATSDR's Cancer Risk Evaluation Guide (CREG). The lifetime excess cancer risk (LECR) associated with the oral exposure route for benzene at the site would present no apparent increased risk of cancer.

The cancer risk associated with benzene exposure at the Delilah Road Landfill site may be interpreted according to the following example. If 100,000 persons were exposed through ingestion for 17 years to the maximum concentration detected in potable wells, at most and additional 3 cases of cancer may occur in 70 years. For the approximately 6 persons at the site who were exposed to benzene in their contaminated well water, it is therefore unlikely that they will develop cancer as a result of their exposure.

    Vinyl Chloride

Site data indicate that exposure to vinyl chloride occurred among residents in the area of the Delilah Road Landfill through the ingestion pathway. For a period of approximately 17 years, one household was exposed daily to vinyl chloride by using contaminated groundwater for drinking and other domestic purposes. Exposure dose assessment assumes that adults drink on the average of two liters of well water per day, while children drink 1 liter of well water per day.

Based upon maximum levels of vinyl chloride detected in potable wells at the site, calculated exposure doses exceeded the ATSDR Minimum Risk Level (MRL) of 0.00002 mg/kg/day for chronic oral exposure. Such concentrations may equal and perhaps exceed the No Observed Adverse Effect Level (NOAEL) for chronic exposure in animals (for effects other than cancer) represented in the ATSDR Toxicological Profile for Vinyl Chloride. At such concentrations, hematological, hepatic, and dermal/ocular effects are possible.

Vinyl chloride is considered by the USEPA to be a known human carcinogen. There is no current oral carcinogenic slope factor from which to calculate a Lifetime Excess Cancer Risk (LECR) value for vinyl chloride exposure at the site. However exposure doses (based upon maximum detected concentrations of the compound in potable wells) are within estimated human cancer risk levels (low increased to no apparent increased risk) represented in the ATSDR Toxicological Profile for Vinyl Chloride. This excess cancer risk may be interpreted according to the following scenario. If ten thousand persons were exposed for 17 years through ingestion to the maximum levels of vinyl chloride found in groundwater at the site, one additional cancer may occur in 70 years. For the members of the one household where vinyl chloride was found in well water it is therefore unlikely that they will develop cancer as a result of their exposure.

    Mercury

Site data indicate that exposure to mercury occurred among residents in the area of the Delilah Road Landfill through the ingestion pathway. for a period of approximately 17 years, between two and ten households were exposed daily to low doses of mercury by using contaminated groundwater for drinking and other domestic purposes. (Mercury data at the site was rejected for QA/QC; ten households represent the maximum number potentially exposed.) Exposure dose assessment assumes that adults drink on the average of 2 liters of well water per day, while children drink one liter per day.

There is no current chronic oral minimum risk level value or oral RfD for mercury. Based upon maximum levels of mercury detected in potable wells at the site, calculated exposure doses were below the no observed adverse effect level represented in the ATSDR Toxicological Profile for Mercury. At such concentrations, it is not likely that adverse health effects would occur.

    Lead

Site data indicate that exposure to lead occurred among residents in the area of the Delilah Road Landfill through the ingestion pathway. For a period of approximately 17 years, 9 households were exposed daily to lead by using contaminated groundwater for drinking and other domestic purposes. Exposure dose assessment assumes that adults drink on the average of two liters of well water per day, while children drink one liter per day.

There is no current chronic oral exposure minimum risk level value or oral RfD for lead. Based upon maximum levels of lead detected in potable wells at the site, calculated exposure doses were below the NOAEL (for animal studies) represented in the ATSDR Toxicological Profile for Lead. However, maximum levels of lead found at the site in potable wells exceeded the USEPA action level of 15 ppb. Children are particularly sensitive to the effects of lead; hematological, renal, hepatic, and neurological effects may have been possible among children exposed in the area of the site.

    Cadmium

Site data indicate that exposure to cadmium occurred among residents in the Delilah Road Landfill through the ingestion pathway. For a period of approximately 17 years, five households were exposed daily to low doses of cadmium by using contaminated groundwater for drinking and other domestic purposes. Exposure dose assessment assumes that adults drink two liters of well water per day, while children drink one liter per day.

Based upon maximum levels of cadmium detected in potable wells at the site, exposure doses were approximately equal to the ATSDR chronic oral Minimum Risk Level of 0.0002 mg/kg/day. At such concentrations, it is not likely that adverse health effects would occur.

    Arsenic

Arsenic was detected in on-site soils at levels exceeding ATSDR comparison values but represents only a potential exposure pathway. No one resides on or comes in long term (chronic) contact with the arsenic contaminated area of the landfill. Although arsenic is known to produce various systemic effects in high concentrations, levels found in on-site soils are not sufficient to induce adverse health effects during short term (acute) exposures.

B. Health Outcome Data Evaluation

Health outcome data for the Delilah Road Landfill site were not evaluated. Four households exhibited potable well contamination above ATSDR comparison values; available databases would not yield observable results for a study population of this size. Should the ATSDR and the NJDOH decide to do so, the health status of those residents whose wells were effected by site related contamination may best be determined by individual case investigation.

The area of the Delilah Road Landfill may be included in the investigation of the area including the Price's Pit Superfund site which is located nearby (3/4 mile) and impacts groundwater quality to a geographically greater extent.

C. Community Health Concerns Evaluation

The primary community concern regarding the Delilah Road Landfill site, specifically the impact of the site on groundwater quality, has been addressed through the introduction of a public potable water supply to the area. Residents were connected to municipal water supplies at State expense in 1989, and private wells were sealed. Since the introduction of the public water supply, community health concerns regarding groundwater quality have been minimal.

One groundwater issue expressed by residents at the NJDEPE public meeting of August 1989 regarded the presence of mercury in domestic wells. Site data indicate that mercury was not found extensively throughout the RI study area. In addition, a mercury plume is not associated with the site. Sources other than the landfill may be contributing to the presence of mercury in area groundwater. In addition, estimated exposure doses for mercury in groundwater are below the NOAEL cited in the ATSDR Toxicological Profile for Mercury (see Toxicological Evaluation sub-section); therefore adverse health effects are not likely.

The issue of site closure and accessibility is addressed in the Record of Decision (September 1990) for the site. Although not yet implemented, a preferred alternative which includes capping, gas collection, runoff control, and access restrictions has been selected.

    Public Comment Period

The New Jersey Department of health conducted a public comment period for the Public Health Assessment of the Delilah Road Landfill site from March 28, through April 29, 1994. The Public Health Assessment was placed in local repositories to facilitate written commentary and reaction from the public at large. In addition, the document was circulated to the Atlantic County Health Department for the purpose of soliciting commentary by local Health Officials.

A summary of the commentary received by the NJDOH and associated responses is presented in Appendix 1.

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