Olin Corp. consultants Thursday defended the company
’s contention that perchlorate from its former Tennant Avenue
site could not flow north and contaminate city wells.
Olin Corp. consultants Thursday defended the company’s contention that perchlorate from its former Tennant Avenue site could not flow north and contaminate city wells.
City Manager Ed Tewes, in a much shorter statement, disagreed and said the Olin report is based on selective analysis and questionable conclusions that left out telling facts and figures that prove that it could.
Mike Turaszki, a hydrogeologist from Olin consultant MACTEC, said he saw no need for Olin to investigate the northern flow further. Tewes disagreed.
George Cook, Santa Clara Valley Water District’s representative to Perchlorate Community Advisory Group, agreed with Tewes.
“Water district engineers) have similar problems with the technical part,” Cook said at the meeting.
Whether Olin will be required to perform further studies north of its site will be decided by the state Regional Water Quality Control Board.
The city and the water district are preparing their response to the report and ask for public comment.
Sylvia Hamilton, PCAG chair will collect comments –by Friday, Oct. 1.
Getting a favorable decision from the board – requiring Olin to study further the northeast flow by drilling monitoring wells – is important to the city because, if the city wells are polluted with Olin’s perchlorate, Olin could be ordered to reimburse the city for its costs.
Morgan Hill costs for dealing with perchlorate in city wells are reaching $4 million; Olin will soon have reimbursed the city $780,000 to replace the one well it accepts responsibility for. The city hopes to eventually get reimbursed for digging the new Butterfield replacement well to the tune of $600,000 but, said Jim Ashcraft, public works director, it’s only a hope. They have not agreed to that.
Olin shows no sign of being willing to consider paying for anything else but, by January, city residents will be paying a 10 percent perchlorate surcharge on their monthly water bills.
Turaszki explained that MACTEC had studied decades of groundwater flow reports and determined that water always flowed south, southeast from the site,. And water always flows from high to low elevations.
Tewes said the city found that, yes, water generally flowed south but even Olin showed instances in which it flowed north in this area.
Given the geologic irregularities that allow flow in different directions and underground streams, the city contends that it is quite possible for Olin perchlorate to end up in Nordstrom well.
And, Tewes said, the Olin site has an elevation of 280 feet; the contaminated Condit well an elevation of 271.
“Models are based on a concept,” Tewes said. “If the concept is poor, the results will be poor.”
Turaszki presented possible alternative sources of perchlorate including local July Fourth fireworks.
Olin manufactured safety flares using perchlorate almost daily at its site for more than 40 years.
There may be another way of proving where the chemical came from. David Athey, a regional board project manager, said he had heard that a strontium nitrate isotope is being used to “fingerprint” perchlorate.
Copies of all reports from Olin Corp. and agency responses are available at the Morgan Hill Library. Reports are online at www.valleywater.org/ Sylvia , sy******@*****il.com or 683-2667.
