GILROY
– The new state health goal for perchlorate levels in drinking
water may mean dozens of South County wells will no longer be
considered unsafe, but for now, it won’t change much for residents
whose wells are contaminated with the toxin.
GILROY – The new state health goal for perchlorate levels in drinking water may mean dozens of South County wells will no longer be considered unsafe, but for now, it won’t change much for residents whose wells are contaminated with the toxin.
Residents who qualify will continue receiving bottled water, and until Morgan Hill city officials evaluate the new guidelines, they will continue to consider wells that measure above the previous “action level” unsafe.
“We haven’t decided what, if any, level of perchlorate we’re going to allow in the water,” Morgan Hill Mayor Dennis Kennedy said.
The state’s Office of Environmental Health Hazard Assessment announced Thursday that it set a public health goal for perchlorate in drinking water at 6 parts per billion. The established standard makes California the first state to regulate perchlorate, a primary ingredient in rocket fuel and fireworks detected in unsafe amounts in as many as 450 South County wells.
The former action level for perchlorate, or the level at which water providers must notify their customers, was 4 ppb. The higher standard announced Thursday caused some to question whether the change would affect the cleanup of local wells and contaminated soil or bottled water deliveries to impacted homes.
Roughly 70 percent of local wells have tested between 4 and 6 ppb. While no public wells in Gilroy have tested positive, a handful of private wells have – none above 6 ppb. Under the new state guidelines, those wells are considered safe.
“Just don’t take away our bottled water,” said Sandy Petersen, a San Martin resident who attended Friday’s regular meeting of the Perchlorate Citizens Advisory Group.
Olin Corporation, which manufactured flares at a Tennant Avenue factory that spread a perchlorate plume through southern Morgan Hill and into San Martin, has been delivering bottled water to residents whose wells measure as low as 2 ppb.
The Olin representative who deals with perchlorate issues was unavailable to discuss whether the company’s policy would change.
David Athey, an engineer with the Regional Water Quality Control Board, told Petersen it is unlikely that Olin will stop its deliveries.
“I doubt very seriously, from my standpoint, that anything will change that quickly,” he said.
The City of Morgan Hill currently does not operate wells that test above 4 ppb. California recommends shutting down wells with perchlorate levels at 40 ppb or higher. City Manager Ed Tewes said officials would evaluate the new public health standard before summer.
“We are not proposing to have any changes until we have that evaluation,” Tewes said. “We have a number of wells that are off-line now, and yet we have sufficient capacity to meet our water demand. However, in the summer, our water demand raises significantly, so … we will need more water capacity to meet our water demand.”
That could mean using water from wells that test between 4 and 6 ppb.
“For organizations that produce water, we have to use whatever the limit is that’s established. So right now, we will be using the 6 parts per billion in relation to what we produce in water for the customer,” Gilroy City Manager Jay Baksa said. “(Gilroy has) never had a hit on our city wells, so the immediate is, there’s no issue with us.”
While residents likely will be forced to “live with” wells that measure up to 6 ppb, they can rest assured that the goal for cleanup is still to leave groundwater perchlorate-free.
“The fact that this level’s been set at 6 (ppb) doesn’t relieve Olin of the responsibility to clean up the soil to the levels they were before,” Kennedy said.
“This won’t affect cleanup,” said Eric Gobler, an engineer with the Regional Water Quality Control Board. “And I say that because the (board’s) policy is to cleanup to background.”
“Background” refers to the amount of the toxin that would naturally occur in groundwater. For perchlorate, the background level is zero.
The new 6 ppb standard caused varied reaction among those attending Friday’s advisory group meeting. Some said it is too high; others said it’s too low.
The public health standard completes the first of two steps necessary to set a working drinking water standard. The 6 ppb target is based solely on health concerns, or what is safe for more vulnerable consumers, such as fetuses, children, pregnant women and the elderly. Perchlorate can impair thyroid function and cause tumors.
Next, the state Department of Health Services will set a maximum contaminant level, a standard that comes as close to the health goal as possible to the extent technologically and economically feasible. This level might not be set for another year.
State Assemblyman John Laird, who attended Friday’s regular Perchlorate Citizens Advisory Group, said the public health goal may trigger a debate process to revise the standard.
“I think overall (6 ppb) is not a bad start,” Laird said. “Lower would have been better … but 6 is realistic enough that we can pull it back if we have a discussion that goes that way all along.”
“I’m very pleased that the state has stepped up to the plate,” said Sylvia Hamilton, who chairs the Perchlorate Citizens Advisory Group. “That not only tells our state and our community, but our country, that perchlorate is something that needs to be dealt with.”
Hamilton said she was disappointed that the public health goal was not set at 2 ppb – the low end of the range that was considered.
“It’s important to remember that 6 and 4 aren’t that far apart,” said Tom Mohr, an engineering geologist with the Santa Clara Valley Water District. Perchlorate tests can have a 20 percent margin of error, he said, and levels often fluctuate over time.
