Massachusetts drinking water standard a third of California’s
public health goal
Morgan Hill – The nation’s first drinking water standard for perchlorate has been enacted in Massachusetts.
The level, set at 2 parts per billion for the contaminant known to interfere with thyroid activity, is a reversal of a recent trend in perchlorate studies by public agencies.
Last year, a panel convened by the National Academies of Science issued a figure for a safe daily dose of perchlorate that translated to a level higher than 20ppb. Recently, the U.S. Environmental Protection Agency set a clean-up standard of 24.5ppb. The EPA had previously issued a health goal of 1ppb.
Officials at the Massachusetts Department of Environmental Protection said the standard is based on the latest scientific evidence and is necessary to the most vulnerable populations, infants and pregnant women. But the standard could further cloud an already confusing issue.
Every perchlorate standard that has been released as been trumpeted as the pinnacle in health protection. California has a public health goal for perchlorate of 6ppb. In January, the Olin Corp. which polluted South County’s water supply, proposed to clean the groundwater basin to a level of 11ppb.
In a report to the Central Coast Regional Water Quality Control Board, Olin stated that a perchlorate “concentration of 11ppb is most certainly protective of all members of the population including the most sensitive receptor, the pregnant woman and her fetus.”
The Massachusetts standard will not affect the cleanup level ordered for South County groundwater, an official with the Central Coast Regional Water Board said Wednesday.
The water board has the authority to order Olin to clean the basin to background levels of perchlorate, assuming it is technologically and economically feasible to do so. The Massachusetts DEP said 2ppb presented no cleanup challenges.
One other factor that could play into Olin’s cleanup efforts is a forthcoming drinking water standard from the California Department of Health Services.
The DHS has been working on setting a drinking water standard since 2004. Officials at the DHS would not comment on whether the Massachusetts standard would figure into the California standard, the drinking water standard can not be lower than the public health goal. The DHS would also not divulge when the drinking water standard will be released.
The Massachusetts standard requires polluters to clean drinking water supplies to a level of 2ppb. The regulations also require regular testing of all public water systems.
Matt King covers Santa Clara County for The Times. He can be reached at 779-4106 ext. 201 or e-mail mk***@mo*************.com
