GILROY
– To protect its water supply from perchlorate, the city must
spend $2 million to install equipment needed to filter out the
rocket fuel ingredient and $80,000 a month to keep special filters
working efficiently.
GILROY – To protect its water supply from perchlorate, the city must spend $2 million to install equipment needed to filter out the rocket fuel ingredient and $80,000 a month to keep special filters working efficiently.
And the costs won’t end there.
The city likely will have to purchase 1,600 square feet of real estate at three of its eight well sites so the ion exchange filtering system has room to be installed – roughly $48,000 of icing on an already costly cake.
“It’s pretty pricey, that’s for sure,” said Mike Goodhue, a senior civil engineer for the City of Gilroy.
Goodhue will unveil the city’s so-called perchlorate contingency plan to City Council on Monday. The plan is a combination of putting filters on existing wells and finding new wells that can deliver enough water to meet future demands.
Future demand has already prompted the city to budget for new wells, however the threat of perchlorate on the city’s water supply is forcing the water division to speed up the process by a couple of years.
At roughly a million dollars each, the city likely would purchase and construct no more than two well sites over the next year to 18 months. Once the two sites are found, drilling would begin immediately.
Goodhue said at least seven sites around town have been identified which now need to be tested for pumping capacity and water quality. They sites are located at:
• Uvas Creek and Thomas roads
• Farrell and Wren avenues adjacent to Anotonio Del Buono school
• Santa Teresa Boulevard and Third Street
• a former city well site at Forest Park
• El Roble Park
• Las Animas Park maintenance yard
• San Ysidro Park.
Clean well water is crucial to the city. Gilroy uses wells for 100 percent of its drinking water supply.
“The more well sites we have, the better off we are (if perchlorate contaminates Gilroy’s public wells),” said City Administrator Jay Baksa.
Although one or two additional sites are being looked at on private property, these seven potential well sites are on public land, which could save the city perhaps tens of thousands of dollars in these slim-budgeted times.
Five private wells in Gilroy between Leavesley and Gilman roads east of U.S. 101 have tested positive for the toxic chemical perchlorate.
Now, of the roughly 450 contaminated wells between Tennant Avenue in Morgan Hill and north Gilroy, six are located south of Leavesley Road. The first contaminated well in Gilroy was found in June, when a test on a private well at Holsclaw Road south of Gilman Road showed a 4.7 parts per billion (ppb) contamination level.
The level at which the state requires water users to be warned about perchlorate is 4 ppb. The five most recent detections ranged from 4 ppb to 6.4 ppb.
The contaminant has yet to be detected in the city’s eight existing wells. The most recent results are based on tests done in November. Results from tests done in December have not yet been made available from the lab.
As for the $2 million-plus equipment installation at the existing wells, staff needs City Council approval before it can begin work or make any purchases. If Council does not approve the purchase of the equipment, staff is hoping the city dais at least authorizes them to begin prepping the sites so equipment can be installed as soon as perchlorate is detected.
Staff will not ask Council to consider installing the ion exchange filters at four of the city’s eight wells.
“The other wells are far enough away from the perchlorate plume,” Goodhue said. “We don’t expect them to get hit, at least not in the short term.”
If Council is in a spending-friendly mood, it could authorize the city to begin the prep work at both existing and new wells.
The prep work, Baksa said, would involve purchasing the land and running pipe from the well to where a filtration system would eventually go.
Baksa said there is a chance Olin Corp. – the company which polluted the aquifer – would have to pay for the pricey filtration system. However, if the wells show no detection of perchlorate and the city funds the installation of a filtration system now, Gilroy and Olin could find themselves in complex legal wranglings to determine who should ultimately pay for what.
The city will base its choice of new well sites largely on how much water is produced at a site, rather than the quality of the water, according to Goodhue.
“Right now we have to go out and test the potential well sites and see what the water quality is,” Baksa said.
