Public Comment -- April 2, 2004
Discussion on possible regulatory strategies to address currently unregulated contaminants in drinking water was prompted by the recent release of studies showing that mans more contaminants are present in raw and finished drinking water supplies than are currently regulated. Studies conducted by the Department with the Environmental and Occupational Health Sciences Institute (EOHSI) of New Jersey (1) and the US Geological Survey (USGS) with NJDEP (2) and the federal Centers for Disease Control and Prevention (CDC) (3) have shown that water samples analyzed by advanced analytical methods contain low levels of household, commercial, and industrial compounds. Current analytical methods used for regulatory purposes are not capable of detecting these compounds.
In the USGS surface water studies (2,3), using analytical methods developed specifically to detect target chemicals, the types of compounds found were primarily pesticides, prescription and non-prescription pharmaceuticals, fragrances, flame retardants, plasticizers, and household chemicals and their metabolites. The compounds detected in the ground water study (1), using analytical methods developed to "screen" water samples for a broad range of semi- and non-volatile organic chemicals, were reported as "tentatively identified compounds". A tentatively identified compound is one that can be seen by an analytical testing method, but its identity and concentration cannot be confirmed without further analytical investigation. Tentatively identified compounds are reported in virtually all analytical tests for organic compounds, but laboratories vary in how they deliver this information. A photograph can be used as an analogy to describe a tentatively identified compound. The photograph's subjects, analogous to the target compounds, are located in the foreground and are in focus and identifiable to the viewer. The photograph also captures background information, analogous to the tentatively identified compounds, and, often, this information is fuzzy and not identifiable to the viewer. The photographer can ask others to identify the fuzzy components and name them, but since he has not identified them for himself they remain tentative identifications.
Despite the differences among the studies described above, there are several noteworthy similarities in their conclusions:
Analytical methods are capable of detecting hundreds of organic chemicals at levels below one part per billion, ppb (a.k.a., microgram per liter, (ug/L) in surface, ground and drinking water samples.
Some contaminants survive existing water treatment.
Some contaminants are introduced during water treatment or appear as a result of chemical interactions during treatment (e.g., chlorination or ozonation).
Most water samples contained more than one organic contaminant.
Only a fraction of the detected compounds in the studies have regulatory standards, guidelines, or criteria.
Little is known about human health effects and even less about ecological effects of the compounds detected.
Quality assurance procedures are vital for interpretation of results (certain compounds were detected in both water samples and blank samples).
Summaries and full reports for the completed portions of these studies are available at:
http://www.state.nj.us/dep/dsr/
or
http://toxic.usgs.gov/regional/emc.html
(Click on the above links to go to those documents)
Human health effects data for many of the unregulated and tentatively identified compounds have not been generated. It is not possible for the Department to develop the toxicological study data needed to establish a maximum contaminant level for all these compounds, given the large numbers of them (several hundred) and the amount of time and expense associated with developing the toxicological data. For example, to conduct toxicity studies on one unregulated contaminant present in the drinking water supply in Toms River, New Jersey, it has taken over 5 years and $5 million. Further, there is little information or guidance available about the health effects of mixtures of two or more compounds, as researchers continue to pursue this field of study (8,9).
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