GILROY
– The Olin Corporation is again calling on ion-exchange
technology to treat potentially dangerous perchlorate-contaminated
drinking water used by about 200 San Martin homes and
businesses.
Ion exchange is pushing perchlorate levels below 4 ppb in San Martin
GILROY – The Olin Corporation is again calling on ion-exchange technology to treat potentially dangerous perchlorate-contaminated drinking water used by about 200 San Martin homes and businesses.
Olin, which dumped the perchlorate while making flares in Morgan Hill from 1955 to 1996, announced Wednesday it has reached an agreement with the San Martin County Water District – a private well company not to be confused with the Santa Clara Valley Water District, a regional government body – to install an ion-exchange system that would treat groundwater pumped from the company’s main well. Olin is spending about $350,000 on the system and plans to activate it by the end of this year.
“This is another important milestone that is part of Olin’s continuing effort to resolve perchlorate issues in a positive and proactive way,” Olin Project Manager Garland Hilliard said in a prepared statement Wednesday.
Within the last two months, Olin used the same technology to treat two wells owned by the West San Martin Water Works Inc., which serve roughly 250 homes and businesses. So far, several of these customers say the $500,000 operation has lowered their perchlorate levels to consistently below California’s “action level” of 4 parts per billion.
“It’s been non-detect (below 4 ppb); I think they’ve tested two or three times,” said involved San Martin resident Sylvia Hamilton, a West San Martin Water Works customer and chair of the Perchlorate Community Advisory Group. “Obviously, I want it to be zero (ppb), but I think it’s wonderful that that many people can have their water (cleaned up).”
Jim Crowley, who heads the SCVWD’s Groundwater Cleanup Oversight Unit, said he doesn’t know of any West San Martin Water Works customer whose water hasn’t consistently tested below 4 ppb since the ion-exchange system was installed.
Crowley confirmed that ion exchange works.
“That system should be effective in reducing the concentration,” Crowley said. “Probably for those (well) systems, it’s the most cost-effective.”
The California Department of Health Services has approved similar ion-exchange systems for other parts of the state, and Crowley expected DHS officials to keep a careful eye on this one.
“They’ll be required to go through some pretty rigorous testing … by the Department of Health Services,” Crowley said. DHS officials will probably want to inspect the final system before they approve it, Crowley added.
Perchlorate is a white powder used in the combustion of rocket fuel, explosives and flares. Tests have shown it can disrupt the thyroid gland’s ability to make essential hormones, though there is debate over the concentration at which it does so. Researchers from Texas Tech University say it is most dangerous to fetuses, infants and children, in whom it can cause lowered IQ, mental retardation, hearing and speech loss and motor-skill deficits.
In addition to finding perchlorate in drinking water, Texas Tech researchers have found it at more than 4 ppb in California supermarket lettuce and in supermarket cow’s milk and human breast milk in Lubbock, Texas.
The perchlorate Olin dumped has spread through the soil and created an approximately eight-mile plume south from Morgan Hill to Gilroy, with nearly 400 wells testing over the state action level. Many residents are scared, as are their representatives. At a Sept. 12 meeting of the Central Coast Regional Water Quality Control Board, South Valley residents and municipal leaders took Olin to task, saying the company needed to spend more effort cleaning up people’s wells. Olin also has to clean up the soil on the site of its former Morgan Hill factory and is disagreeing with government officials on how to go about this.
According to Santa Clara County District 1 Supervisor Don Gage, “What we want is some results.”
At a Sept. 25 meeting in San Martin of the Perchlorate Community Advisory Group (which Hamilton chairs), Gage said, “They (at Olin) haven’t done anything as far as I’m concerned,” to the agreement of several members of the PCAG board. What he meant, he said Wednesday, was that Olin hadn’t done enough up to that point to mitigate the perchlorate it dumped.
“They were dragging their feet, and I think that we want action,” Gage said. “I’m glad to see them doing something.”
While ion exchange so far looks like an effective method of treating wells, Hamilton is pushing regional and state officials to thoroughly study all perchlorate-removal technologies “to make sure that we’re getting the very best protection available.” Just because most alternatives are newer and less tested than ion exchange, she said, “that doesn’t mean they shouldn’t be looked at and studied.”
Olin has been providing bottled water to those whose drinking water tests above 2 ppb – until that water has four consecutive tests below 4 ppb.
At the South County courthouse and sheriff’s office – served by West San Martin Water Works – Olin recently withdrew the bottled water it had been paying for, saying the tap water is safe to drink.
The equipment used by the SCVWD cannot detect perchlorate in water at below 4 ppb, but local private labs the district does business have much more sentitive equipment. One Morgan Hill lab the district sends samples to can detect perchlorate at concentrations as low as 0.4 ppb, according to Crowley.
