Olin Corp. 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 Corp. 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 road flares in Morgan Hill from 1955-96, announced Wednesday it has reached an agreement with the San Martin Water District – a private water 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 firm’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.
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 approximately 250 homes and businesses.
The City of Morgan Hill is currently operating an ion-exchange treatment plant on its Nordstrom well to reduce the presence of perchlorate in well water and it plans to install a similar plant at the Tennant well, across the street from the Olin site.
So far, several West San Martin Water Works 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 chairwoman 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.
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.
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, in one test Texas Tech researchers have found it at more than 4 ppb in California supermarket lettuce and, in another test, in supermarket cow’s milk and human breast milk in Lubbock, Texas.
The perchlorate from the Olin plant has spread through the soil into the underground aquifer 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 concerned, 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 now. Olin also has to clean up the soil on the site of its former Morgan Hill factory. Olin is still in discussions with Regional Board 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 later, 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.”
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 now safe to drink.
