MORGAN HILL
– New, more lenient California guidelines for perchlorate levels
in drinking water mean many contaminated South County wells are no
longer considered unsafe, at least by the state.
MORGAN HILL – New, more lenient California guidelines for perchlorate levels in drinking water mean many contaminated South County wells are no longer considered unsafe, at least by the state.
The Office of Environmental Health Hazard Assessment announced Thursday a public health goal for ammonium perchlorate in drinking water, making it the first state in the nation to set a standard for the toxin.
After conducting a study, the agency determined that perchlorate levels of 6 parts per billion or lower does not pose a significant health risk to humans. The news comes in the midst of lawsuits against the company that polluted South County’s wells, and during a time when cities like Gilroy, which relies completely on wells to supply drinkng water, scramble to protect their systems against the rocket fuel ingredient.
The next step for the state will be to set a maximum contaminate level, which officials say will take up to a year. A MCL is the highest level of a chemical allowed in drinking water and is typically higher than the public health goal.
The mark of 6 ppb is 2 ppb higher than the level currently used by the state as an “action level,” the point at which water providers must notify their customers of the chemical’s presence. It is not the level at which they must stop serving the water – 50 ppb – though the City of Morgan Hill shuts down its wells when they test higher than 4.
The effect of the new state guidelines on South County is uncertain. Roughly 70 percent of perchlorate contaminated wells in South County have tested below 6 ppb.
The Santa Clara Valley Water District took out an ad in today’s Gilroy Dispatch to address the state’s decision.
“We were kind of afraid people would be confused and think we aren’t going to take care of their wells anymore,” water district spokesman Mike DiMarco said. “Our goal has not changed. We still want to clean up the groundwater basin, so a change in a state number is sort of irrelevant to us.”
A level of 4 ppb had been used to determine which well owners would receive bottled water deliveries.
In Gilroy, only a handful of private wells have tested positive for perchlorate. None of them tested higher than 6 ppb.
Tests on the city’s wells have come up clean thus far.
Morgan Hill City Manager Ed Tewes said he would wait and see what the impacts of the state’s new guideline would be.
“Until a new maximum contaminant level is established, we will still use the action level of 4 ppb,” Tewes said. “We are not going to face what this will do to Morgan Hill until it is certain, until we know what the MCL will be.”
The public health goal is only a guideline, not a standard.
“While it is not a regulation, this goal provides scientific guidance to health authorities in setting a regulatory standard for perchlorate in drinking water,” said Dr. Joan Denton, a director within the state’s Environmental Protection Agency.
The City of Morgan Hill has been trying to obtain reparations from Olin Corp. for costs related to perchlorate levels higher than 4 ppb. Several wells had to be temporarily closed and the city bought and installed a perchlorate treatment plant on the Nordstrom well after a summer heat wave brought water reserves down to dangerous levels.
Water rates recently went up citywide to pay for perchlorate-related costs.
If 6 ppb is considered safe, Morgan Hill’s attempts to keep levels below 4 ppb may no longer hold water in court, and Olin Corp. may not have to reimburse the city.
Olin Corp. already sent the city a check for $455,384.50 followed by other payments to cover the cost of digging a replacement for the Tennant well. It is not known whether the city would have to repay the money if an ultimate MCL were to be higher than the levels in the Tennant well, though initial perchlorate levels in the Tennant well were far higher than 6 ppb.
And if 6 ppb is accepted, private wells with levels between 4 and 6 ppb could be deemed safe and residents would no longer receive the free bottled water they have been drinking since the widespread pollution of hundreds of South Valley wells was discovered in early 2003.
San Martin resident Bob Cerruti, whose well on Moreno Court has high levels of perchlorate and can’t be used, commented on the heart of the problem.
“That should let Olin off the hook,” Cerruti said.
Cerruti’s well normally tests between 8 and 9 ppb. The highest level detected in an area well was 98 ppb.
Cerruti said he was uncertain about the effect of the new state guideline on San Martin residents with wells contaminated by perchlorate.
Perchlorate was discovered in January 2003 to have contaminated the South Valley underground aquifer, polluting public and private wells from Morgan Hill, through east San Martin to north Gilroy. The chemical came from 40 years of safety flare manufacture at an Olin Corp. plant, since removed at Tennant and Railroad avenues.
The U.S. military, which is responsible for most of the perchlorate pollution in California and elsewhere in the country, had called for a delay in issuing the safety guideline pending further studies. The chemical is used to make rocket fuel, fireworks and highway safety flares burn more efficiently, but the state went ahead with Thursday’s announcement.
The release from the state agency said the public health goal was reached from a review of all available scientific studies on the health effects of perchlorate.
“OEHHA based the PHG on data from a highly regarded 2002 study in which human volunteers (all healthy adults) were given perchlorate in drinking water over a 14-day period. Using a well-accepted method, OEHHA scientists added margins of safety to the study’s data on adults to calculate a PHG that protects the susceptible populations.”
Environmental groups are calling 6 ppb too high, saying it is six times higher than initial Federal Environmental Protection Agency recommendations.
“The final PHG of 6 ppb … is insufficient to protect the health of fetuses, bottle-fed infants and pregnant women,” said Sujatha Jahagirdar, a Environment California clean water advocate.
Larry Ladd, a private citizen in perchlorate polluted Rancho Cordova who has turned his life over to studying the chemical and in advocating for cleanup, would have preferred the lower level of 4 ppb, a number he is fairly comfortable with.
“Six ppb is less than ideal, but it beats continuing to pretend there’s not a problem,” Ladd said. “What’s unfortunate about a 6 ppb PHG is that it doesn’t touch the Colorado River, where it can bioconcentrate in alfalfa hay fed to dairy cattle by an order of a 1,000. It leaves the door open for a higher MCL.”
When news that perchlorate had contaminated much of the South Valley’s groundwater hit Morgan Hill and San Martin residents, little was known about what levels were safe to humans. Neither the federal nor the state government had set a safety goal. During the ensuing months, officials from medical, scientific and environmental communities met to review existing studies and gather data from fresh ones.
A deadline of Jan. 1, 2004, was delayed because the change in California governors in October also replaced department and agency heads throughout government and, according to Assemblyman John Laird, D-Santa Cruz, the new crew had to be brought up to speed.
No federal standard has been set.
• The Perchlorate Citizens Advisory Group will hold its monthly meeting from 2 to 4 p.m. today at the San Martin Lion’s Club, 12415 Murphy Ave. behind the airport. The public is welcome. • The full PHG document for perchlorate is available at www.oehha.ca.gov. • More details: www.smneighbor.org, www.valleywater.org or call Sylvia at 683-2667.
