The state agency in charge of the perchlorate contamination
cleanup in South Valley groundwater issued an order Wednesday
telling Olin Corp. that it must supply uninterrupted bottled water
to residents with contaminated wells. An Olin representative said
Thursday that the company will appeal part of the order.
The state agency in charge of the perchlorate contamination cleanup in South Valley groundwater issued an order Wednesday telling Olin Corp. that it must supply uninterrupted bottled water to residents with contaminated wells.
An Olin representative said Thursday that the company will appeal part of the order.
The order issued Wednesday by the state Regional Water Quality Control Board in San Luis Obispo covers both interim and long-term actions, addressing who will continue to receive free bottled water – residents on wells testing at least 4 parts per billion – and which well-owners must be provided with a long-term alternative source of water – those with wells registering 10 parts per billion or more.
The alternative source would likely be a well-head treatment system. Olin also is required to submit detailed plans for the uninterrupted water supply options for wells testing from 4 to 9.9 ppb, almost 400 wells in tests performed a year ago. The same round of tests showed about 20 wells with levels above 10 ppb.
Olin’s Rick McClure said the company will appeal having to provide bottled water for residents with 4-5 ppb since the California Department of Health Services in March set 6 ppb as the Public Health Goal.
A PHG is the point at which water consumers must be notified of the chemical’s presence. The 4 ppb level is the lowest that can be detected.
McClure said the company has no problem with having to provide an alternative water source for wells higher than the PHG. Treating fewer wells translates into lower ultimate costs.
Several dozen wells in the area from Morgan Hill to just north of Gilroy have tested between 6 ppb and 10 ppb while only a few register higher than 10 ppb.
The company can stop distributing bottled water to any resident whose water tests less than 4 ppb, or nondetect, for four straight quarters, though Olin will still need to continue to check the levels in those wells according to the RWQCB order.
The City of Morgan Hill adheres to the 4 ppb standard, closing any well that tests above that level. According to California law, a water supplier needs not close a well until it reaches far higher levels.
At Wednesday’s City Council meeting, City Manager Ed Tewes announced that the Condit well, long-closed because of perchlorate levels, had tested at 5 ppb, higher than it has for months. It remains shut down. All other city wells, working and closed, tested non-detect, or below 4 ppb.
The perchlorate comes from 40 years of manufacturing highway safety flares at an Olin Corp./Safety Fusee site on Tennant and Railroad avenues. The chemical was found in January 2003 to have leached down through soil contaminated on the site and discovered to have traveled south east through San Martin to north of Gilroy, polluting hundreds of wells.
Perchlorate at a still undetermined level is known to cause thyroid and other health problems. There have been no long-term studies to determine the health impact of perchlorate at different levels.
