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Water Health Assessment
(Dover Township) Toms River, New Jersey
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Conclusions
Draft for Public Comment -- November 16, 1999
Conclusions
As part of an investigation of the incidence of childhood cancer in Dover Township, Ocean County coordinated by the New Jersey Department of Health and Senior Services (NJDHSS) and the federal Agency for Toxic Substances and Disease Registry (ATSDR), the NJDHSS and the New Jersey Department of Environmental Protection (NJDEP) have evaluated the quality of water served by the community water supply.
A thorough chemical and radiological analysis has been conducted on samples from the water distribution system the eight points of entry, and over 20 wells. NJDHSS, NJDEP, and ATSDR have concluded the following:
In this investigation, a previously unidentified contaminant was discovered in Parkway well water samples in varying estimated concentrations, the highest levels being found in well 26. The unknown material was identified in November 1996 as isomers of THNA and THNP, collectively known as styrene-acrylonitrile (SAN) trimer. The SAN trimer is now known to be an unintended by-product resulting from
the synthesis of styrene-acrylonitrile co-polymer. The presence of SAN trimer is attributable to the Reich Farm waste site groundwater contamination plume. The time of initial contamination is not known, nor are historic concentrations known. There is evidence of SAN trimer in the distribution system in March 1996 at levels of approximately 1 ug/l.
Exposure to SAN trimer was interrupted in November 1996 by temporary voluntary closure of the Parkway well field. By May 1997, activated carbon treatment of wells 26 and 28 was installed and treated water was discharged to the ground. (However, treated output from these wells may be pumped into the distribution system in times of high water demand.) Because of sporadic detection of SAN trimer in well 29,
activated carbon treatment was installed for this well and for well 22 in June 1999, interrupting the potential exposure pathway.
The public health implications of SAN trimer contamination cannot yet be assessed. The toxicity testing of the SAN trimer, coordinated by the USEPA, will assist in making this determination.
Low levels of trichloroethylene were found in certain wells of the Parkway well field as early as 1986. The installation of a packed tower aeration treatment system at two wells (26 and 28) in 1988 served to reduce exposure to TCE, although TCE detections continued to occur due to sporadic contamination of an untreated well (#29). Subsequent activated carbon treatment of well 29 should interrupt exposure to
TCE through this well. TCE is a common industrial solvent and has been a frequent drinking water contaminant in New Jersey and the U.S., often at levels many times higher than what was found in the UWTR system. TCE is classified as a probable human carcinogen based on animal and human worker studies. While epidemiologic studies suggest an increased risk of leukemias and/or lymphomas from exposure to TCE-contaminated drinking water,
they are not considered conclusive.
Gross alpha radiological activity is elevated in water provided by some of the points of entry into the UWTR system, particularly those in which a large proportion of water comes from the shallow Kirkwood-Cohansey aquifer. According to the NJDEP and the U.S. Geological Survey, the problem of relatively high gross alpha activity attributable to radium species is not confined to the Dover Township area. Rather, there appears to be a
general elevation in radium-related activity throughout the shallower aquifer systems of southern New Jersey. Occupational radium exposure has been associated with increased risk of bone and paranasal sinus cancers in highly exposed workers. Radium in drinking water has been associated with increased bone cancer incidence in adolescents and with leukemia incidence in adults but not children, but the epidemiologic evidence is inconclusive.
At some schools, elevated lead and copper were found in first-draw samples but not in flushed samples, indicating corrosion of metals from building plumbing. Corrosion is a problem common to many community water systems. Since 1989, federal and State agencies have recommended that all schools establish routine flushing programs to reduce exposure to these metals in drinking water. Exposure to accumulated lead can have adverse effects on the neurologic
development of children. High levels of copper in drinking water may result 'in acute gastrointestinal effects.
Although the UWTR system appears typical in most respects, the presence of an unusual chemical at the Parkway well field, a sign of impact from the Reich Farm groundwater contamination plume, appears to be a characteristic unique to the area. Although little is known of the toxicologic implications of this impact, it is reasonable to consider exposure to this water source in epidemiologic investigations of childhood cancer in Dover Township.
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