San Martin wells perchlorate contaminated

– Perchlorate has been found in several new private wells – and
now some public wells – outside the original boundaries of Tennant
Avenue, Monterey Road, Masten Avenue and Center Avenue.
SAN MARTIN – Perchlorate has been found in several new private wells – and now some public wells – outside the original boundaries of Tennant Avenue, Monterey Road, Masten Avenue and Center Avenue.

According to Mike DiMarco, spokesman for the Santa Clara Valley Water District, test results the district received Tuesday showed signs of the chemical west of Monterey Road and south of Masten Avenue. Both areas are in San Martin, not in Morgan Hill or Gilroy.

DiMarco was still trying to confirm the details Wednesday morning, but he said the West San Martin Water Works – a public entity – had asked the Department of Health Services to test some wells west of Monterey Road and south of San Martin Avenue. He said two “hits” were found with levels – as yet unconfirmed – of six to eight parts per billion, but stressed the information is preliminary.

“We’re still trying to confirm the details of the West San Martin well testing results,” he said. “We don’t want the public to panic about this new information.”

West San Martin Water Works officials could not be immediately reached for comment before press time Wednesday morning.

DiMarco also said that several owners of private wells south of Masten Avenue had tested their own wells. Results from a private laboratory showed levels at two wells between four and five ppb. The level at which human beings and animals are effected by the chemical is unknown, but a level of four ppb is the “action level” mandated by the state.

DiMarco said the district would release more specific information about the number and location of the wells – and on the perchlorate levels found – as soon as that information is available, possibly this afternoon.

The chemical originated at the now-closed Olin Corp. plant on Tennant and Railroad avenues in Morgan Hill. The company, and Standard Fusee Company, manufactured road safety flares and similar products from 1955 to 1997. Perchlorate is a by-product of such manufacture.

The chemical leached into the underground water table – the aquifer – and traveled, mostly in a southeasterly direction, according to SCVWD.

Residents who drink from the wells inside (or near) the original boundaries have been supplied with free bottled water from the Crystal Springs Water Company since the problem became known. SCVWD has been testing the 450 to 500 wells within the boundaries – at no cost to the owners. It takes about three weeks for results to be received.

The water district had notified the public in mid-January that the chemical had been found in 12 of 100 private wells in the area, with levels from 90 at the U-Save Rockery just south of the former plant, down to four to seven parts per billion at the other 11.

Morgan Hill and Gilroy public wells have tested perchlorate-free since Morgan Hill officials closed that city’s contaminated well last April and replaced it with a new facility.

The SCVWD will host an informational meeting at San Martín/Gwinn Elementary School, 100 North St., from 7 to 9 p.m. on Feb. 12 to update south Santa Clara County residents about potential effects of the perchlorate.

The meeting will discuss the cause of the contamination, potential health effects, agricultural concerns and future potential cleanup strategies to safeguard residents.

The district has invited representatives from the county’s public health office, the county’s agricultural commissioner’s office, the Central Coast Regional Water Quality Control Board, U.S. Environmental Protection Agency, University of California Cooperative Extension Office and other agencies to attend.

More information on the search for the chemical in South County water systems and help for affected residents is available at