Olin Corp. has until Oct. 3 to submit a plan for sampling wells
north of its Tennant Avenue site polluted by perchlorate.
Olin Corp. has until Oct. 3 to submit a plan for sampling wells north of its Tennant Avenue site polluted by perchlorate.
The announcement was made Friday, Sept. 12 at the quarterly meeting of the Central Coast Regional Water Quality Control Board, the state agency in charge of the contamination of the groundwater from Morgan Hill, through San Martin and Gilroy.
Previously the company was only concerned with wells south of the site where, for 40 years, it manufactured road flares, using perchlorate as an oxidizer to enable the flares to burn more efficiently.
At last Friday’s meeting, officials from Morgan Hill, San Martin and Gilroy urged the Regional Board to hasten the pace at which Olin is working to clean up the contaminated groundwater in the southern-moving plume. City Manager Ed Tewes also urged the board to take action on the contaminated wells north of the site.
The Sept. 4 order to submit an expanded cleanup plan came from Roger W. Briggs, RWQCB executive officer.
Briggs’s letter asks Olin to “submit … a plan for determining if detections of perchlorate found in wells between Olin’s site and Morgan Hill’s Nordstrom Park well are related to Olin’s perchlorate releases at its site.”
Olin is to identify all wells within one-fourth mile of either side of a line between the two sites. Further, Olin is to provide data from those wells within the line that have been tested for perchlorate and propose a monitoring and sampling program that will expose the extent of the perchlorate plume in the northern area.
The new boundaries miss one important site – the Condit well, said Jim Ashcraft, city public works director. Aside from that, he said he was just about satisfied with the Regional Board’s action.
“I think we were all pleased,” Ashcraft said. “The order was almost sufficient,” he said. “It just missed the Condit well by 200 feet.”
Ashcraft said the city had sent a letter to the Regional Board through the Santa Clara Valley Water District asking the board to amend the letter to include the Condit well.
When and if that is done, Ashcraft said, he will be happy with the scope of the order.
The city shut down the Condit and three other wells this year when they showed action levels of the chemical – 4 parts per billion or higher.
The Sept. 4 letter gives reasons why the board is considering Olin as the source of perchlorate north of the site.
“Olin’s property on Tennant Avenue is the only site in the area that we are aware of with confirmed releases of perchlorate to the environment,” the letter said.
There are conditions, he said, that could cause “perchlorate-degraded water” to travel from Olin’s site to the northeast. Pumping from many wells could influence the plume, he said. The fact that the underground aquifer in the area is relatively shallow and could be affected by years of irrigation with perchlorate-contaminated water that leached down back into the groundwater.
Rick McClure, Olin’s project manager for the Tennant Avenue clean up project, did not return repeated phone calls over a two-day period about the latest development.
The designated sampling area is fairly narrow – only one-half mile wide – and doesn’t include dozens of private wells east of the line, some of which find perchlorate in their wells and who have said they felt abandoned by the authorities who were helping others.
Homeowner Jackie Rodriguez, who lived near the intersection of San Pedro and Murphy avenues had her water tested when she decided to sell her house in the spring. Testing turned up levels of 5.4 ppb. Rodriguez was not satisfied with the initial response from the Santa Clara Valley Water District.
“We communicated with valley water and the Regional Board,” Rodriguez said, “and we urged them to get our wells tested by Olin and bring us bottled water. They urged us to test our wells.”
“We’d like to be able to help,” he said, “but we can’t act capriciously. We need data and evidence to show that Olin is the cause.”
Rodriguez eventually did sell her house but at a reduced price because, she said, of the water.
The Regional Board has now taken action.
