Road flare manufacturer Olin Corporation has released a 100-plus
page report for the perchlorate plume stretching south through San
Martin that defers until August a cleanup solution on the area
immediately south of the company’s former Tennant Avenue
factory.
Morgan Hill – Road flare manufacturer Olin Corporation has released a 100-plus page report for the perchlorate plume stretching south through San Martin that defers until August a cleanup solution on the area immediately south of the company’s former Tennant Avenue factory.
The document addresses options for cleaning the remaining areas in the 9.5-mile-long plume, suggesting more of the same: a passive monitoring program of the alleged water contamination that would be carried out over 20 years to the tune of $5.6 million.
Olin Corp. also explored a more aggressive and thorough cleanup strategy in the report, which would have cost $250 million and reduced perchlorate levels in the South County water table to 4 parts per billion (ppb).
The California Water Board in March 2004 set a public health goal for the maximum amount of perchlorate at 6 parts per billion (ppb). Perchlorate is a sodium that can conflict with healthy thyroid activity if ingested at high enough levels.
Olin Corp. rejected the more expensive cleaning approach including pumping it out of the ground for treatment and then replacing the cleansed water and depositing it back to the water table.
Tom Mohr, a geologist with the Santa Clara Valley Water District, said he understands some people may criticize Olin Corp. for pursuing a less expensive route, but he thinks the proposed measures are reasonable at face value.
“When you get into money like $250 million, even if from a corporation, you have to weigh the societal cost of that,” said Mohr, adding that some middle ground might still be deemed suitable.
The report was submitted to the Central Coast Regional Water Control Board on June 30. The water board may make revisions to the document.
Rick McClure, who oversees the South County cleanup effort for Olin Corp., declined to comment on the report saying he was on vacation when contacted by Thursday by The Dispatch. His signature, however, appears in the report’s cover letter.
Hector Hernandez, the water board engineer working the case, is also on vacation this week and could not be reached for comment.
One of Hernandez’s coworkers, Thea Tryon, also declined to comment on the report, explaining neither she nor Hernandez had adequately reviewed it.
As for parts of the cleanup report that were deferred until August, the reason for the delay is so Olin’s consultants can further study the water table surrounding its former industrial site.
To that point, consulting engineers at a June 29 Perchlorate Community Advisory Committee meeting in San Martin explained to the public they had not yet fully characterized the depth of the deepest aquifers beneath the old road flare factory, which operated from 1955 to 1987.
Previous drilling and testing has shown substantial levels of perchlorate remain in the region roughly bound by Tennant Road, Middle Avenue, Highway 101 and Monterey Road.
Other areas affected by the plume, however, seem to have decreasing levels of perchlorate, information that Olin Corp. used to justify its passive, and less expensive, approach to handling the potential environmental hazard.
Mohr said the Olin’s proposed monitoring program may not sit well with some residents, but he also suggested that peace of mind could be purchased for about $300, the cost of a reverse osmosis unit that can remove perchlorate – and other prevalent contaminants such as nitrate – from the kitchen sink.
In addition to perchlorate, South County has a widespread nitrate issue, a common problem in agricultural regions that rely on groundwater.
