The announcement opens public comment period
Morgan Hill – The California Department of Health Services has proposed a maximum contaminant level (MCL) for perchlorate in drinking water of 6 parts per billion, undercutting the standard of 24 ppb Olin Corp. recently cited in its cleanup feasibility report.
State Public Health Officer Dr. Mark Horton announced the proposed MCL Monday. If the proposed standard is adopted, public water systems would not be allowed to provide drinking water that exceeds the MCL without notifying their customers and must take steps to bring their water supply into compliance with drinking water regulations.
The department’s announcement opens a public comment period that ends Nov. 3. A public hearing will be held at 10am Oct. 30 in department’s auditorium, located at 1500 Capitol Ave., Sacramento.
“Establishing the MCL allows CDHS to address a contaminant that, unfortunately, is quite common in certain areas of California,” Horton said in a written statement. “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.”
Perchlorate, primarily used in rocket fuel, explosives, fireworks, road flares and airbag inflation systems, is an inorganic chemical that is known to interfere with iodine uptake of the thyroid gland. A reduction in iodine uptake can result in decreased production of thyroid hormones, which are needed for prenatal and postnatal growth and development, as well as for normal metabolism and mental function in the adult. Â
State law requires CDHS to establish a MCL for perchlorate that protects public health, but also is as close to the Public Health Goal as technically and economically feasible. Public Health Goals are levels of contaminants in drinking water that would not be expected to pose a significant health risk to individuals consuming an average of two liters a day of water over a 70-year lifetime.
A Public Health Goal of 6ppb for perchlorate was established in 2004 by the California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment. The level is consistent with the proposed MCL and findings of a 2005 report on the chemical by the National Academy of Sciences.
“I’m very pleased the department of health services took the actions they did and kept the MCL as low as they could, which means it’s more protective of folks in the community,” said Sylvia Hamilton, chairwoman of the Perchlorate Community Advisory Group in San Martin.
CDHS began monitoring for perchlorate in 1997. In 1999, CDHS required water systems to monitor for the chemical as an “unregulated contaminant” to collect information on the extent of contamination throughout the state. Results from nearly 7,000 drinking water sources in California showed perchlorate to be present in about 450 sources in 110 public water systems.
Roger Briggs, executive officer of the Central Coast Regional Water Quality Control Board, said he’s happy the proposed MCL matches the state’s public health goal.
“I think we would have been harder pressed to defend a cleanup level that’s less than 6ppb if the MCL had been 23 ppb,” Briggs said, using a random number as an example.
In its recently released cleanup feasibility report, Olin cited the Environmental Protection Agency’s MCL of 24 ppb.
Hamilton said she’s glad a stricter standard is being proposed in California.
“Having an enforceable standard in place provides a stronger position for stockholders on this contamination issue,” she said.
Nevertheless, Briggs said the public health goal and the pending MCL are not the only factors in the Olin cleanup debacle.
“The first thing we do is take a look at the background level,” Briggs said.
Tony Burchyns covers Morgan Hill for The Times. Reach him at (408) 779-4106 ext. 201 or tb*******@mo*************.com.
