The perchlorate contamination that devastated Morgan Hill and
San Martin
’s underground water supply is surfacing as a major campaign
theme in Gilroy, even though the chemical has hit barely a handful
of private wells here thus far.
The perchlorate contamination that devastated Morgan Hill and San Martin’s underground water supply is surfacing as a major campaign theme in Gilroy, even though the chemical has hit barely a handful of private wells here thus far.
Five of Morgan Hill’s municipal wells have been taken off line temporarily or closed permanently because of the perchlorate contamination, all, the city insists, from the Olin Corp. site on Tennant Avenue.
City Manager Ed Tewes announced at the Oct. 22 council meeting that, while all wells in production tested nondetect – less than 4 parts per billion – the Condit well, closed to the Olin site, had tested at 4 ppb and would remain off line. A treatment plant attached to the Nordstrom well has allowed that well to be brought back into use.
In Gilroy, one mayoral candidate has called the toxic subterranean plume a rights violation and has tested her own family’s water three times. Another mayoral hopeful says the city is not doing enough to inform citizens of the problem.
Likewise, in the City Council race, one pro-environment candidate says dealing with perchlorate contamination was a key reason he decided to seek office. While another candidate, who is a fiscal conservative, worries about the perchlorate because its presence may mean spending millions of city dollars to dig new wells.
“It’s coming this way, get ready for it,” said City Council candidate and lifelong Gilroyan Dion Bracco. “Even if it bypasses us it’s going to hit the Pajaro (River) basin. If it gets into the irrigation system, California is going to get a reputation for watering its crops with bad water and that could be crippling to agriculture.”
In a campaign forum last week, Bracco addressed the perchlorate issue from a fiscal conservative perch. The local business owner who used to drill wells for a living said authorities must find a way to stop the plume from traveling further south and contaminating Gilroy wells because drilling new ones would run about $1 million a pop.
Gilroy uses eight wells to supply residents with all of their drinking water.
Even though issues such as Wal-Mart, downtown revitalization and job creation dominate most political conversations, how candidates stand on the perchlorate issue may sway the votes of some residents in a Nov. 4 election many believe will be close.
“This is very much a front burner issue at least with the people I’m talking to (while doing door-to-door campaigning),” says mayoral candidate Lupe Arellano. “We should focus on letting the citizens know more about what is happening.”
It’s no back burner issue for the City of Gilroy either, says City Administrator Jay Baksa. Next week a special task force of city staff will meet, Baksa said, to begin formulating a plan that deals with delivering a safe drinking water supply if perchlorate enters city wells.
If perchlorate contaminated a city well today, there would be no need for a back-up delivery plan, Baksa said. In fall and winter months, consumer demand drops off and the city’s water delivery capacity does not get fully tapped.
“A large well getting contaminated in the middle of summer is a sort of worst-case scenario, and that’s what we’re planning for,” Baksa said.
Of the city’s eight wells, the three nearest the perchlorate plume account for more than half the city’s water supply.
Details of the back-up plan, which will be presented to City Council likely in January, are not yet available. However, Baksa said digging new wells to make up for the lost water supply would be a last resort, longer term solution.
Immediate steps would be citywide water conservation and installation of water treatment systems at each contaminated well.
The water treatment systems would likely be ion exchange units that use filters to separate chlorine atoms from oxygen atoms. Perchlorate molecules are part chlorine and part oxygen.
Morgan Hill, which also uses wells as a drinking water source, installed ion exchange systems on two wells in August to help meet summer demand.
Morgan Hill Public Works Director Jim Ashcraft said running each treatment system costs the city $210,000 over a three-month period. The wells with the treatment system will go off-line on Saturday, Ashcraft said, since demand has dropped.
Treatment systems on Gilroy wells could be more expensive to operate. Morgan Hill’s wells pump 1,000 gallons per minute. Gilroy wells pump between 1,100 and 2,440 gallons per minute.
The good news for Gilroy is that Olin Corp. is the overwhelmingly likely contaminator, making it easier to get the company to pay for treatment costs.
Olin Corp. dumped perchlorate while making flares in Morgan Hill from 1955 to 1996. The perchlorate plume has moved south from the defunct factory at Tennant Avenue to south of Leavesley Road in Gilroy.
Of the nearly 450 contaminated private wells between Tennant Avenue in Morgan Hill and north Gilroy, six are located south of Leavesley Road, bringing the city more deeply into the perchlorate mix in recent months.
In June, a perchlorate test on a private well at Holsclaw Road south of Gilman Road showed a 4.7 parts per billion (ppb) contamination level. In August, five private wells between Leavesley and Gilman roads east of U.S. 101 tested positive for the toxic chemical.
So far, only one city well – a monitoring well not used in the drinking water supply – has tested positive for perchlorate. As of Oct. 7, none of the city’s drinking water wells has shown traces of perchlorate.
