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HEALTH ASSESSMENT

ROCKAWAY BOROUGH WELLFIELD
ROCKAWAY BOROUGH, MORRIS COUNTY, NEW JERSEY
EPA FACILITY ID: NJD980654115

April 17, 1989


TABLE OF CONTENTS

SUMMARY

BACKGROUND

ENVIRONMENTAL CONTAMINATION AND PHYSICAL HAZARDS

DEMOGRAPHICS OF POPULATION NEAR SITE

EVALUATION

PUBLIC HEALTH IMPLICATIONS

CONCLUSIONS AND RECOMMENDATIONS

PREPARERS OF REPORT

REFERENCES



SUMMARY

The Rockaway Borough Well Field is a National Priorities List (NPL) site located in the Borough of Rockaway, Morris County, New Jersey. Because of yet unidentified source(s) of TCE and PCE in ground water, municipal wells of the Borough of Rockaway have been contaminated sometime prior to 1980, when this well water was found to contain high concentrations of these volatile organic compounds (VOCs). Since 1981, an activated carbon filtration system has been treating raw well water before distribution to an estimated 11,000 users of the Borough of Rockaway's municipal water system. Since the installation of the activated carbon treatment system, elevated concentrations of TCE and PCE were detected in the water supplied by the distribution system only once, because the activated carbon in the treatment unit was not replaced on time (i.e., the breakthrough of the contaminant occurred). It is not likely that breakthrough will occur again because of the remedial action provided by the Environmental Protection Agency's Record of Decision. Based on information received, ATSDR has concluded that this site is of a potential public health concern because of the risk to human health resulting from possible exposure to hazardous substances at concentrations that may result in adverse health effects. As noted in the Human Exposure Pathways Section below, human exposure to elevated concentrations of TCE and/or PCE may occur, be occurring, or have occurred via oral, dermal, or inhalation exposure to contaminated municipal drinking water (only in the unlikely event that breakthrough occurs) or private well water (i.e., residential potable water or industrial process water use).


BACKGROUND

A. SITE DESCRIPTION

Rockaway Borough Well Field is a National Priorities List (NPL) site located in the Borough of Rockaway, Morris County, New Jersey. The site has been defined by the Environmental Protection Agency (EPA) as three municipal wells, which are the sole source of potable water for the Rockaway Borough, and portions of nearby Denville and Rockaway Townships. Eight other wells previously used for potable water supply by the Borough were abandoned because of their lack of productivity.

Volatile organic compounds, primarily trichloroethene (TCE) and tetrachloroethene (PCE), were first detected in these wells in 1980. On February 28, 1981, an emergency was declared, and the residents supplied by the distribution system were advised not to use their tap water for drinking and cooking. Temporary drinking water supplies were made available to the public in tank trucks provided by the National Guard. The Borough of Rockaway installed an activated carbon water treatment system in July 1981 to reduce contaminant concentrations. The New Jersey Department of Environmental Protection (NJDEP) and the Borough of Rockaway have been monitoring the water for VOCs on at least a monthly basis since the installation of the activated carbon treatment system. The exact source of the ground water contamination in these municipal wells is not known; however, several sources are suspected. The exact source of the ground water contamination will be investigated by the EPA during Phase II of the Remedial Investigation. The length of time, before 1980, that ground water in these municipal wells was contaminated is not known.

A Record of Decision (ROD) for the site was signed on September 29, 1986. The remedial actions selected in the ROD are:

1. The Borough should operate and maintain the existing granular activated carbon treatment system. Operations should be modified to ensure compliance with current Safe Drinking Water Act standards. The EPA advised that the spent carbon should be regenerated off-site.

2. EPA will continue the Remedial Investigation and Feasibility Study to positively identify the contaminant source(s), further delineate the full extent of contamination, and evaluate additional remedial action alternatives to address those sources.

In addition, the Borough of Rockaway was directed by the EPA to monitor their wells for VOC levels on a monthly basis.

The Draft Final RI and Feasibility Report (RI/FS) was issued in May 1986.

B. SITE VISIT

An adequate site description was obtained from the Remedial Investigation Report and the Agency for Toxic Substances and Disease Registry (ATSDR) Regional Representative. Therefore, no site visit was conducted.


ENVIRONMENTAL CONTAMINATION AND PHYSICAL HAZARDS

A. ON-SITE CONTAMINATION

The contaminants of concern, found in the raw water from these municipal wells, and in finished treated water, are considered on-site contamination. (Table I). The monitoring data represents a summary of sampling results conducted by the Borough of Rockaway, the NJDEP, and the EPA (RI) between the years 1980 and 1986. The NJDEP and EPA were the lead agencies for Phase I and Phase II of the RI, respectively. The water samples obtained from the municipal wells during the RI were analyzed for the Priority Pollutant List (PPL) compounds. Other samples were analyzed for VOCs because of problems encountered at the laboratory.

B. OFF-SITE CONTAMINATION

The contaminants of concern, found in the samples other than those from municipals wells, are considered off-site contamination (Table II). Samples collected were from surface water and sediment (Rockaway River and Beaver Brook), soil gases, ambient air, ground water monitoring wells, three residential water wells, and three industrial water wells. Except for the first round of sampling, where the samples were analyzed for the PPL VOCs and heavy metals, total phenols, and cyanide, all samples (except soil gas and ambient air analyses) were analyzed for the complete PPL compounds.

The surface water and sediment samples from the Rockaway River and the Beaver Brook did not indicate the presence of any appreciable concentrations of the contaminants of concern. Only one of the residential wells is used as a source of potable water. Lead (52 ug/L) and TCE (4.1 ug/L-estimated value) were found in the water from one of the residential wells and is currently not used for any purpose. Contaminants of concern were not found in the water from the one residential well used as a source of potable water supply (GW-9). In addition, one industrial well (GW-2) showed elevated concentrations of heavy metals which may be associated with use of pumps at the well head.

Soil gas monitoring results showed PCE and TCE at a maximum value of 3,100 ppb and 19 ppb, respectively. The maximum value for PCE was encountered in a sample from soil covered by pavement. Ambient air monitoring data did not indicate any appreciable concentrations of the contaminants of concern at the site.

C. PHYSICAL HAZARDS

No site-specific physical hazards were reported in the information reviewed by ATSDR.


TABLE I: RANGE OF ON-SITE CONTAMINANTS OF CONCERN

CONTAMINANT UNBLENDED RAW WATERa
(ug/L)
BLENDED RAW WATERb
(ug/L)
TREADED WATER
(ug/L)
Trichloroethene (TCE) 0.5-172 1.0-41.2 ND-14.8C
Tetrachloroethene (PCE) 2.0-678 1.5-335 ND-25.4C

a- Combined contaminant concentration range for municipal wells 1, 5, and 6.
b- contaminant concentration range for blended water from all municipal wells.
c- TCE and PCE concentrations in treated water resulting from improper operation and maintenance of the activated carbon in the treatment facility.
ND-Not detected.
NR-Not reported.
ug/L- Micrograms per liter.


TABLE II: RANGE OF OFF-SITE CONTAMINANTS OF CONCERN

CONTAMINANT GROUND WATER MONITORING WELLS
(ug/L)
Trichloroethene (TCE) 253a
Tetrachloroethene (PCE) 4.8-1,170

a-Detected in only one sample
ug/L- Micrograms per liter.


DEMOGRAPHICS OF POPULATION NEAR SITE

The site is located in a suburban residential setting and is surrounded by homes, businesses, and municipal property. An estimated 6, 383 persons lived in the Borough of Rockaway in 1980. In addition, the Borough of Rockaway's municipal wells supply potable water to about 11,000 persons (ROD, 1986).


EVALUATION

A. SITE CHARACTERIZATION (DATA NEEDS AND EVALUATION)

1. Environmental Media

The conclusions and recommendations made in this Health Assessment are based on the information and monitoring data provided. The following information and monitoring day, as detailed in this section, are needed to characterize the site and to evaluate the public health concerns completely. The recommendations based on these data needs are presented in the Conclusions and Recommendations Section. Additional information and monitoring data, as it becomes available, may necessitate a reevaluation by ATSDR of the public health concerns associated with the Rockaway Borough Well Field NPL Site.

Ground water monitoring VOCs, at least on a quarterly basis, for private water wells (residential or industrial) identified in the area is needed in order to evaluate any future significant human exposure to TCE and/or PCE through oral, dermal, or inhalation exposure to drinking water from the private residential well or inhalation exposure to volatilized VOCs from industrial well water used in manufacturing.

2. Land Use and Demographics

Adequate information is available to evaluate the land use and demographics of the Rockaway Borough WELL Field NPL site.

3. Quality Assurance and Quality Control (QA/QC)

QA/QC was performed on all of the RI data reviewed for this Health Assessment. It is not known if the NJDEP and the Borough of Rockaway monitoring results have passed QA/QC standards. The EPA data reviewed for this Health Assessment passed the QA/QC requirements. Conclusions contained in this Health Assessment are based on the information received by ATSDR. The accuracy of these conclusions is determined by the availability and reliability of the data.

B. ENVIRONMENTAL PATHWAYS

GROUND WATER

As previously stated, the source(s) of the TCE and PCE plumes have not been definitively established. This will be investigated by EPA during the Phase II RI. Soil gas and ground water monitoring have identified several potential sources of TCE and PCE contamination in the area of the well field.

Two aquifer systems exist in the subsurface formations underlying the site. The upper aquifer is composed of sand and gravel with layers of till, and the lower aquifer is composed of a mixture of metamorphic, igneous, and metasedimentary bedrock. The lower bedrock aquifer is the most productive of the two; therefore, most wells, including the Borough of Rockaway's wells, are completed in this hydrogeological unit.

The natural direction of ground water flow in the area is not well established (RI, 1986). However, the Borough of Rockaway's highly productive wells have a significant effect on localized ground water flow direction because of the cone of depression they produce. In addition, given the highly fractured nature of the lower aquifer, the potential for contaminant migration in any direction exists. Based on information provided in the RI, the Rockaway River, which is located within about 1,000 feet south of the Borough of Rockaway's wells, may recharge the aquifers in some areas of the site, and in other portions of the site the ground water only partially discharges to the river.

Until the source(s) of the ground water contamination in the area are identified and mitigated, and until the ground water contamination is remediated, the potential exists for contamination of the Borough of Rockaway's well water or the private well water (i.e., residential or industrial) in the area. Monitoring data from 1985 does not indicate any appreciable concentrations of VOCs in these private wells.

SURFACE WATER (SURFACE RUNOFF)

Based on soil gas and ambient air monitoring data, it appears that most of the contamination is confined to the subsurface soil zones; hence, the potential for surface runoff of contaminants is unlikely. However, this cannot be definitively established until the source(s) of the ground water contamination have been identified and the appropriate subsurface and surface soils in these areas(s) are characterized. Surface water and sediment monitoring data from the Rockaway River or the Beaver Brook (located about 2,000 feet east of the well field) did not indicate appreciable concentrations of the contaminants of concern.

AIR

Based on ambient air monitoring, it appears that appreciable concentrations of VOCs are not present in the air. When the source(s) of the contamination is found, additional ambient air monitoring in these areas, especially in potentially affected enclosed spaces, would be needed to confirm or deny the presence of appreciable concentrations of VOCs at potential exposure points.

CONSUMABLE BIOTA

Because most of site-related contaminants (i.e., VOCs) are believed to be confined to subsurface zones, and significant contamination of the Rockaway River or the Beaver Brook does not appear to have occurred, the potential for bioaccumulation of site-related contaminants in consumable biota (i.e., terrestrial animals or fish, respectively) is unlikely. Furthermore, TCE and PCE are not known to bioaccumulate to a significant extent in terrestrial animals or fish.

C. HUMAN EXPOSURE PATHWAYS

The contamination of the environmental media previously identified in the Environmental Pathways Section constitute the following potential human exposure pathways of concern:

(1) Potential oral (ingestion) exposure to elevated concentrations of TCE and PCE in the finished municipal well water for the population using the Borough of Rockaway's municipal water supplies. This potential significant exposure can occur if the activated carbon treatment system, employed by the Borough of Rockaway, fails to reduce contaminant concentrations because of improper operation or maintenance. However, it is not likely that breakthrough will occur because of the remedial action provided by the Environmental Protection Agency's Record of Decision.

(2) Potential oral (ingestion), dermal, or inhalation exposure to elevated concentrations of TCE an/or PCE in private residential drinking water as a result of future contaminant plume migration.

(3) Potential inhalation exposure to elevated concentration of TCE and/or PCE in private industrial wells as a result of volatilization of these contaminants during the use of well water for industrial purposes. Current concentrations of VOCs in the private industrial well water do not constitute a significant human exposure pathway; however, future appreciable contamination of these wells, and subsequent significant human exposure, may occur as a result of plume migration.


PUBLIC HEALTH IMPLICATIONS

The public health implications, resulting from potential human exposure to contaminants at the Rockaway Borough Well Field NPL site, are discussed below according to potential human exposure pathways and the contaminants of concern for each of those pathways. TCE and PCE were the major contaminants of concern to human health at the site.

1. Ingestion of TCE and PCE-contaminated municipal well water

TCE is a volatile organic contaminant detected in the finished municipal well water. This contaminant is slightly water soluble and is quite stable in ground water for a period of several months to years; however, TCE can be bacterially degraded by anaerobic microbes to form vinyl chloride. This degradation process does not necessarily mitigate the problem, as the degradation product, vinyl chloride, is also an oral carcinogen, and has been estimated to be more than two orders-of-magnitude more toxic than TCE. The maximum level of TCE detected in finished municipal well water is higher than the Environmental Protection Agency's Maximum Contaminant Level (MCL) of 5 ug/l (USEPA (1987). However, exposure to the TCE levels detected in the municipal wells would not typically result in noncarcinogenic health effects. TCE has also been designated as a probable human carcinogen (Group B2) by the USEPA. The mechanism of carcinogenicty proposed is that TCE is metabolized to a toxic epoxide, which directly interacts with DNA and subsequently, exerts carcinogenic effects (USHEW, 1978). The maximum TCE level, detected in finished municipal well water (14.8 ug/l) is unacceptable and may pose a significant carcinogenic risk to human health with long-term oral exposure.

Based on numerous carcinogenic studies in laboratory animals, PCE has been designated as a probable human carcinogen (Group B2) by the USEPA. Long-term exposure to PCE, at the maximum level present in finished municipal well water (25.4 ug/l), may pose a significant carcinogenic risk to users of municipal well water through long-term exposure.

The human exposure pathways and subsequent potential health effects from ingestion and inhalation exposure to TCE and PCE-contaminated finished municipal well water are of present concern to human health, if the current activated carbon is not replaced and the treatment system fails to reduce contaminant concentrations because of improper operation and maintenance (i.e., breakthrough of the contaminant). Since the likelihood of breakthrough is not currently probable (as a result of the remedial action provided by the EPA ROD), ingestion and inhalation of TCE and PCE-contaminanted municipal well water are not of current probable concern to human health. Past exposure (intermittent) of municipal well users is probable, as a result of breakthrough (once), indicated the need for filter replacement.

2. Ingestion, inhalation, and dermal exposure to TCE and/or PCE-contaminated residential drinking water (future concern)

TCE and PCE were detected at levels of concern to human health in off-site ground water monitoring wells. These contaminants were not detected at levels of concern to human health in off-site residential wells (as discussed in the narrative on Off-Site Contamination). However, the prevalence of these contaminants in off-site ground water monitoring wells and the potential for future plume migration, poses a threat to ground water in off-site private residential wells. Ingestion, inhalation, and dermal absorption would be the human exposure pathways of concern to human health. Long-term oral exposure to levels of TCE and PCE-contaminated ground water (off-site) may result in significant carcinogenic effects and is described in the narrative above. Long-term exposure to maximum levels of PCE, detected in off-site ground water (1.17 mg/l), may also result in noncarcinogenic health effects via oral exposure. PCE is readily absorbed via the lungs, skin, and gastrointestinal tract (Arena, 1974). Particularly susceptible individuals may be those with liver, kidney, nervous system, and blood pressure disorders. Alcohol reacts synergistically with PCE, and heavy alcohol consumers may be particularly at risk from PCE exposure (General Electric Co., (1978). PCE is also a probable human carcinogen (Group B2) via inhalation exposure. Long-term inhalation of PCE-contaminaed vapors during domestic use of ground water may also be of concern to human health. Ingestion, dermal and inhalation exposure would be the possible exposure routes of concern from future domestic use (e.g., drinking water, showering, bathing) of TCE and/or PCE-contaminated residential ground water. There is no appreciable bioaccumulation of these volatile contaminants in the food chain; thus, the irrigation of garden crops with TCE and PCE-contaminated ground water is not a probable concern to human health.

3. Inhalation of elevated TCE concentrations in private industrial wells (future concern)

Inhalation of elevated TCE and/or PCE levels in private industrial wells, during the use of well water for industrial purposes, may be of concern to human health; however, adverse human health effects would result primarily from long-term exposure. The health effects from long-term inhalation exposure (i.e., significant carcinogenic risk) would be concern to human health, if elevated levels of these VOCs continued to contaminate ground water taken from industrial wells for a significant period of time.


CONCLUSIONS AND RECOMMENDATIONS

Based on the public health concerns associated with the Rockaway Borough Well Field site, the following conclusions and recommendations are warranted:

Based on information received, ATSDR has concluded that this site is of a potential public health concern because of the risk to human health resulting from possible exposure to hazardous substances at concentrations that may result in adverse health effects. As noted in the Human Exposure Pathways and Public Health Implications Sections above, human exposure to elevated concentrations of TCE and/or PCE may occur, be occurring, or have occurred via oral, dermal, or inhalation exposure to municipal drinking water (only in the unlikely even that breakthrough occurs) or private well water (residential or industrial).

The ROD remedial measures should mitigate exposure to VOCs from municipal waters as long as appropriate operation and maintenance procedures are implemented to ensure that VOCs do not "breakthrough" the activated carbon water treatment system. Furthermore, if monitoring indicated that VOCs have entered the distribution system, then appropriate measures to reduce exposure should be implemented.

Ground water monitoring for VOCs should be performed, a least on a quarterly basis, for private water wells (residential or industrial) identified in the area. This monitoring is needed in order to evaluate any future significant human exposure to TCE and/or PCE thorough oral, dermal, or inhalation exposure to drinking water from the private industrial well water used in manufacturing.

Institutional controls should be implemented to prevent future use of contaminated aquifers for drinking water supplies in the areas of known ground water contamination, until remediation of all known contaminant sources has reduced concentrations below levels of concern to human health.

In accordance with the Comprehensive Environmental Response, Compensation, Liability Act of 1980 (CERCLA), as amended, the Rockaway Borough Well Field site has been evaluated for appropriate follow-up with respect to health effects studies. Although there are indications that human exposure to site-related contaminants may have occurred in the past, this site is not being considered for follow-up health studies at this time because there are no indication of ongoing exposure and no test is available to evaluate possible past exposures. If data become available suggesting that human exposure to significant levels of hazardous substances in currently occurring, ATSDR will reevaluate this site for any indicated follow-up.


PREPARERS OF REPORT

Environmental Reviewer:

Gregory V. Ulirsch
Environmental Health Engineer
Environmental Engineering Branch

Health Effects Reviewer:

Cynthia M. Harris, Ph.D.
Toxicologist
Health Sciences Branch

Typist:

Charlotta V. Gavin
Clerk Typist
Environmental Engineering Branch


ATSDR REGIONAL REPRESENTATIVE

Regional Reviewer:

Denise Johnson
Public Health Advisor
Field Operations Branch
Region II


REFERENCES

ATSDR Files.

Draft Final Remedial Investigation/Feasibility Report for Rockaway Borough Well Field Site, Rockaway Borough, Morris County, New Jersey, May 1986. Prepared by Science Applications International Corporation for the New Jersey Department of Environmental Protection.

Geyer, H., Kraus, A.G., and Kline, W. "Relationship Between Water Solubility and the Bioaccumulation Potential of Organic Chemicals in Rats". Chemosphere 9: 277-291 (1980).

Neely, W.B., Environmental Science and Technology 8: 1113-1115 (1974).

Sitting, M., 1985. Handbook of Toxic and Hazardous Chemicals and Carcinogens. Noyes Data Publications, Park Ridge, New Jersey.

U.S. Environmental Protection Agency, 1986. Superfund Public Health Evaluation Manual. Office of Emergency and Remedial Response, Washington, D.C.

U.S. Environmental Protection Agency. Office of Drinking Water Health Advisory—Trichloroethene (1987).

U.S. Department of Health, Education, and Welfare (National Institute of Occupational Safety and Health). Special Occupational Hazard Review of Trichloroethene, Washington, D.C., 78-130 (1978).

Arena, J.M. and Drew, R.H. Poisoning—Toxicology, Symptoms, Treatments; 3rd ed., p. 185 (1974).

General Electric Company. Material Safety Data Sheet #313 (1978).

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