Locals expected to lobby for more action on the cleanup of
perchlorate from water
An Olin Corp. draft plan to clean up its Tennant Avenue property polluted with perchlorate has been given the once over by the state Regional Water Quality Control Board, Central Coast Region. The RWQCB, the lead agency in the matter, is mulling over its response and expects to reply by letter today, according to Harvey Packard, senior water resources engineer for the board.
“This is not the final design,” Packard said. “These will be general comments on the initial design. There is still lots of data needed and analysis to be collected and done before we would approve the system design”.
The Olin plan will also be discussed at a meeting of the full RWQCB on Friday in Salinas. Packard said the meeting is for discussion only and the board will take no action. Public officials and the public have been invited to speak.
The plan, as it was submitted to the regional board on Aug. 26, involves a two-pronged effort to clean the polluted soil on the site on Tennant and Railroad avenues and to stop polluted water from leaving the site through the underground aquifers. Olin estimates the clean-up cost to be at least $800,000.
“We expect that this system will simultaneously remove perchlorate from the soil and groundwater at our Morgan Hill property,” said Rick McClure, Olin’s project manager for the site. “This cutting-edge approach, which will combine soil and groundwater treatment in a closed-loop system, is one of the first of its kind to be installed anywhere for the treatment of perchlorate. It is part of Olin’s overall commitment to resolving perchlorate issues in the Morgan Hill area.”
To do the first, the company proposes to install an ion exchange plant to treat water on the site by the end of October; the rest of the system, Olin said, will be installed by year’s end. Shallow wells near the middle of the site will draw groundwater into the plant. Ion exchange plants work by passing water through resin beads and causing a chemical reaction to take the perchlorate molecules from water and attach themselves to the resin beads, which are then discarded.
The cleaned water will then be percolated down through the soil, carrying along the soil’s perchlorate to the groundwater capture and treatment system. A second set of wells at the property’s boundaries is designed to remove and treat the groundwater and prevent any untreated water from moving off site.
The Olin plan promises that this “closed loop system ensures perchlorate will be removed from on-site soil and water.“
“This remediation approach combines several treatment elements that are known to quickly and effectively remove perchlorate from soil and groundwater, while maintaining these resources for beneficial future use,” says Evan Cox, an Olin consultant on perchlorate remediation. “This treatment method will remove the perchlorate from the site in the least disruptive manner possible.”
The ion exchange treatment plant is similar to one installed by the City of Morgan Hill with a loan from the Santa Clara Valley Water District on the Nordstrom well. The well was taken off line earlier in the year because its perchlorate levels exceeded the 4 ppb “action level.” A state mandate requires customers to be notified when perchlorate levels in drinking water reaches 4 parts per billion, though the water can still be delivered although cities, including Morgan Hill, often refuse to do so.
Nordstrom is north east of the Olin site and out of Olin’s acknowleged area of responsibility. The West San Martin Water Works wells also boast an ion exchange perchlorate treatment plant, put into place in August by Olin.
Perchlorate originally percolated into the groundwater system during the 40 years in which the Olin Corp. and Standard Fusee Corp. manufactured road flares. Equipment was rinsed out and the rinse water disposed in a holding pond on the site. The plant has been closed since 1996 and was demolished a year later.
The highest level of perchlorate found so far in a well between Morgan Hill and Gilroy is 98 ppb in a well near the Olin site, though that well tested at much lower levels later on.
Packard said the next report – a 45 percent report – is due from Olin on Sept. 19.
As the source of the chemical in wells further south, the Olin site is the first area to be cleaned up .
Olin and the Santa Clara Valley Water District have been providing bottled drinking water for residents who get their water from affected wells within the boundaries of Foothill Avenue, Monterey Road, Tennant Avenue and, originally Masten Avenue, now Leavesley Road in Gilroy.
The company was ordered by the board to clean up the site and, eventually, the groundwater that is also polluted with the chemical. Several hundred private and a few public wells in Morgan Hill, San Martin and Gilroy show detectable levels of perchlorate.
While Olin has consistently accepted responsibility for the set boundaries, it has denied responsibility for perchlorate appearing elsewhere, notably in wells directly east and north east of the site as with Morgan Hill’s Nordstrom well.
The City of Morgan Hill has shut down several wells since January because detectable levels of the chemical were found.
RWQCB MEETING
Elected officials and staff from Morgan Hill, San Martin and Gilroy, Santa Clara County and the SCVWB are planning to attend Friday’s meeting.
Mayor Dennis Kennedy and City Manager Ed Tewes will join the others in lobbying for more action from the board on the perchlorate situation.
“The agencies are doing a joint presentation,” said Tracy Hemmeter of the SCVWB’s Groundwater Management Unit. “Elected officials will be speaking as well as well. And the community is also invited.”
Sylvia Hamilton, chair of San Martin’s Citizen Advisory Group on Perchlorate said she plans to attend and speak.
The City of Gilroy, farthest from the source and only recently finding perchlorate in some of its northern-most wells, will ask for a focus to be placed on stopping the plume from traveling any farther south. They want Olin Corp. and the Regional Board to identify where the plume is, to install a system of sentry wells to monitor the plume and to stop it from polluting Gilroy city wells.
The state RWQCB will meet in Salinas on Friday, Sept. 12, City Council Chambers Rotunda, 200 Lincoln Ave. The meeting begins at 8:30 a.m.; the Olin issue is number nine on the agenda. Also on the agenda – number 26 – is The Math Institute Golf Course, partly owned by John Fry of Fry’s Electronics, seeking permits and environmental approval for the 18-hole course on Foothill Avenue in Morgan Hill. Details and directions: www.scrcb.ca.gov
