Waste News, Bruce Geiselman
Published September 10, 2006
California is proposing a maximum contaminant level for perchlorate in drinking water of 6 parts per billion, becoming only the second state to adopt its own standards.
The federal government has not yet set drinking water standards for the chemical, used primarily in rocket fuel, explosives, fireworks, road flares and airbag inflation systems. However, the Environmental Protection Agency has established a much more liberal cleanup standard of 24 parts per billion.
Environmentalists have been divided in their reaction to California's action, with some believing the 6 parts per billion standard isn't stringent enough. Others praise the state for taking protective steps beyond what the federal government has done.
Under the proposed California standard, public water systems could not provide drinking water that exceeds the standard without notifying its customers and taking steps to bring the water system into compliance.
If the state adopts the standard, proposed Aug. 28, the California Department of Health Services would have the ability to address a contaminant common in many areas, said California Public Health Officer Mark Horton. ``Perchlorate's potential for harm is of concern to pregnant women and their developing fetuses, as well as children, so limiting exposure to this contaminant is important for protecting public health,'' he said.
Perchlorate is an inorganic chemical that interferes with iodine uptake of the thyroid gland. The result can be impaired prenatal and postnatal development, and a reduction in mental functioning, according to the CDHS.
California required water systems to begin monitoring for perchlorate in their water beginning in 1999. Perchlorate was found in about 450 sources impacting 110 public water systems. It has been detected primarily in groundwater wells in Los Angeles, Orange, Riverside, San Bernardino and Sacramento counties, according to the CDHS. It has also been detected in the Colorado River, which supplies water for drinking and irrigation to southern California.
The state will be taking public comments on the proposed rule until Nov. 3.
Massachusetts became the first state in the nation to adopt drinking water and waste site cleanup standards for perchlorate. It announced in July it was setting the standard at 2 parts per billion, three times as stringent as California's standard. The chemical has been detected in 11 public water systems across the Massachusetts.
``The most significant thing here is not the difference between Massachusetts and California, but that two states that are leaders in public health have affirmed that perchlorate in drinking water should be limited to the low parts per billion to account for perchlorate exposure through food and water,'' said Renee Sharp, a senior scientist for the Environmental Working Group.
Tests by EWG and other researchers have found people are exposed to perchlorate not only through drinking water but through consuming milk, lettuce and other foods.
EPA officials have said the agency is still determining if regulation of perchlorate in drinking water would represent a meaningful opportunity for reducing risks to human health. Its studies include looking at the technologies available both for measuring and removing perchlorate contamination.
