California's Rush to Judgment on Perchlorate Drinking Water Standard

By CMTA Staff

Capitol Update, Oct. 23, 2003 Share this on FacebookTweet thisEmail this to a friend

There appears to be a rush to judgment to adopt an extremely conservative drinking water standard for perchlorate based on highly questionable science. This action is unnecessary to protect public health and would be very costly to the California economy.

California regulators (the Cal-EPA Office of Environmental Health Hazard Assessment and the Department of Health Services) are moving to adopt an extremely stringent drinking water standard for perchlorate on an expedited basis. This will result in a standard being set before the National Academy of Sciences (NAS), the nation's premier scientific institution, has the opportunity to complete its evaluation of perchlorate. That evaluation will be completed by the end of 2004.

California regulators have recognized an artificial, preliminary and highly conservative drinking water action level of 4 parts per billion (ppb) for perchlorate and may be considering adopting the final standard at about that level. Perchlorate is present at low levels, generally in the 4-10 ppb range in hundreds of surface and groundwater sources throughout California, including the Colorado River, which supplies up to one-third of California's drinking and agricultural irrigation water. Even in the absence of an enforceable drinking water standard, aggressive cleanup efforts are already underway and are serving to reduce perchlorate concentrations in the Colorado River and elsewhere.

Establishing a permanent drinking water standard of 4 ppb for perchlorate could precipitate a water supply crisis and would have significant adverse economic impacts for California's agricultural industry, water consumers, the building industry and others, with correspondent job losses.

Little water is being served above the 4 ppb action level, so there is no public health risk in waiting for the science to be completed.

State policymakers should allow time to consider the findings of the independent scientific peer review already underway at the NAS to ensure that the best available science is used to adopt a final drinking water standard.

For more information, please visit here (pdf). You may also visit the Council on Water Quality website at, for a comprehensive source of factual information on perchlorate occurrence, health effects, regulatory actions, economic implications and other issues.
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