New tests may prove South County contamination came from
multiple sources
San Martin – An important piece of the perchlorate puzzle should soon be in place.
Armed with federal dollars, the Santa Clara Valley Water District will try to figure out just how much of the perchlorate in South County’s groundwater can be pinned to the Olin Corp.’s former road-flare factory in Morgan Hill.
The company has assumed responsibility for much of the contamination. But Olin also maintains that some of the pollution is from other sources, and that it shouldn’t be held solely responsible for cleaning the Llagas sub-basin.
Tom Mohr, an engineer with the water district, said new tests may prove Olin right. And without a clear understanding of where the perchlorate is coming from, it will be hard to clean the groundwater basin.
“It appears pretty obvious that here is a plume emanating from the Olin site and flowing southward,” Mohr said recently. “If you look at the map there are detections in unexpected locations. Olin is an obvious source, but we may have made a forgone conclusion based on where we expected perchlorate to be. Because we don’t know with any clarity, we want to learn if there is a background perchlorate level.”
Since the pollution was revealed in January 2003, Olin and the water district have conducted hundreds of tests on wells from Morgan Hill to Gilroy. Most of those tests have conformed to a pattern consistent with the Olin plume. But tests have also found perchlorate in outlying areas, and most puzzling, north of the site. Those results point to other possible polluters or contamination from natural causes. A series of studies in other areas of the country have shown how hard it can be to draw a bright line between a source and contamination.
“We can’t afford to ignore what’s happening in the rest of the country,” Mohr said, referring to a Texas study that suggests perchlorate is found in rain, ozone and lightning, and another in Massachusetts that blamed perchlorate pollution on expired household bleach. “Remote, or even ‘Twilight Zone,’ as these sources may be, none of them are impossible.”
All along, Olin has tried to leaven its responsibility with arguments that South County’s perchlorate comes from many sources, including rocket testing at the now-closed United Technology Corp. plant in Coyote, and road flares used on U.S. Route 101.
“There are many different areas where we believe there is at least one other source,” said Rick McClure, Olin’s perchlorate project manager. “There is a distribution of perchlorate in some unusual locations.”
For now, the agency directing the cleanup effort will operate as though Olin is the sole polluter, though David Athey, of the Central Coast Regional Water Resources Control Board, said he will “keep an open mind.”
“If there are any other sources of perchlorate, Olin hasn’t shown any proof,” Athey said Tuesday. “Most, if not all of it, is coming from Olin. There’s pretty good evidence now, but we’re going to keep an open mind.”
Olin has also vehemently maintained that it is not responsible for the perchlorate northeast of the site. The water district will also test that region with new forensic methods that hold the possibility of settling that question.
Just how much the results – Mohr expects the testing to take about a year – will influence the cleanup is unclear. Olin must propose a cleanup level by Jan. 31, 2006, and a final plan by June 30. But if the tests reveal other sources of perchlorate, the company may not have to do all of the cleaning on its own. In a worst-case scenario for county residents, cleanup costs could be passed along to water users.
“I don’t know how a big a role it would play,” Athey said. “The discharger has to address their portion of the discharge. If there is another discharger, that will come into play when we do the corrective action plan. Anything’s on the table right now because we just don’t know.”
What is perchlorate?
Perchlorate is a salt used to make rocket fuel, highway flares, matches and air bag
accelerators. It can interfere with thyroid activity, especially in small children and pregnant women, but the scientific
community is split over how much perchlorate is too much.
How did Perchlorate end up in San Martin?
The Olin. Corp. polluted South County’s at its now-abandoned road-flare factory on Railroad Avenue in Morgan Hill. Earlier this summer, a federal jury exonerated the company on charges that it did so knowingly.
What Happens Next?
• The Santa Clara Valley Water District and Olin will conduct separate studies to determine if there are sources of perchlorate other than Olin’s factory. Those studies will help gauge Olin’s responsibility and guide the company’s cleanup efforts.
• The district will test the area north of the Olin factory to find the source of that contamination. Olin says it’s not responsible for any pollution north of the factory.
• The district will test whether pumping clean water through recharge ponds will clean the groundwater.
