San Martin – A new plan to accelerate cleanup of the perchlorate
plume that has spread south of the former Olin Corp. site in Morgan
Hill has been developed by the Perchlorate Working Group.
San Martin – A new plan to accelerate cleanup of the perchlorate plume that has spread south of the former Olin Corp. site in Morgan Hill has been developed by the Perchlorate Working Group.

“We think we have an approach that will give people certainty that the wells will be cleaned up sooner rather than later,” Santa Clara Valley Water District Senior Project Manager Tracy Hemmeter said Friday. “Normally this is something that would take decades of work and controversy, but we’re hoping to see cleanup begin next year.”

Perchlorate was discovered at the site in January 2003 and found to have traveled through south Morgan Hill, San Martin east of Monterey Road (largely) and into north Gilroy.

The Working Group is made up of the Water District, the Perchlorate Community Action Group of San Martin and the cities of Gilroy and Morgan Hill. Its plan calls for the Regional Water Quality Control Board to issue a cleanup order to Olin next year.

David Athey, the Control Board’s project manager for the Olin site, said Friday that the Board welcomes the plan, but that it’s too early for his agency to order Olin to clean up the plume.

“Even when they’ve disagreed with us, Olin has been cooperative,” he said. “We anticipate we will probably get to that point, maybe in the next year, but we don’t have a hard and fast date.”

So far, the plume has not spread to Gilroy. The city tests its wells monthly and has not yet found traces of perchlorate, according to Operations Manager Carla Ruigh.

Before the plume can be cleaned up, it’s exact parameters need to be mapped out. Hemmeter said that the Working Group plan calls for research into what she called “gaps in the data,” and the installation of additional monitoring wells.

It’s estimated that the plume is 10.5 miles long, but no one knows for sure how wide it is. There are also questions as to whether Olin is responsible for a northeast plume that has reached Diane Ave. in Morgan Hill.

Earlier this year, the Control Board rejected Olin’s arguments that it is not responsible for the northeast plume. The Board has since directed the company to study the feasibility of a new forensic testing method to determine the source of that perchlorate.

Speaking at a PCAG meeting Friday, Athey said that the Control Board wouldn’t force Olin to use the forensic method unless there is clear evidence that it’s reliable.

As for the site itself, the bacteria that’s been eating perchlorate and nitrates in excavated soil there is almost finished with dinner.

Dry weather has slowed the project, Athey said, but most of the perchlorate has been eaten by the bacteria and levels in the mound have fallen about 98 percent. Some samples have tested negative. Once the process is complete the dirt will be put back in the ground and treated again.

As cleanup continues, so do discussions by various governmental agencies about the maximum acceptable levels of contamination in food and water.

California’s Department of Health Services is working toward setting a maximum contamination level. That decision is at least a year away, but it can’t be lower than the public health goal set by the state’s Environmental Protection Agency, which is currently six parts per billion.

The wild card is a forthcoming report from the National Academy of Sciences, which is due the second week of January and will set federal guidelines for maximum contaminant levels.

Reed Addis, representing Assemblyman John Laird, said at the PCAG meeting Friday that the level set by the NAS will likely influence the public health goal for the California EPA.

“What we don’t know,” he said, “is whether it’s going to go up or down.

Andria Ventura, of Clean Water Action, said Friday that her organization is concerned about the results of that study because it has been formulated through a series of mostly closed meetings, in part by people with ties to a defense firm.

“We’re worried about NAS studies because there are panel members with strong links to Lockheed Martin,” she said.

It was also announced Friday that PCAG has been named a Groundwater Guardian by the Groundwater Foundation in Lincoln, Neb. There is no funding attached to the award, but the designation allows the Water District to lend staff and support.

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