MORGAN HILL
– The City of Morgan Hill received bad news this week when two
municipal wells tested above the state
”
action level
”
for perchlorate and were shut down. The source of the
contamination is unknown.
MORGAN HILL – The City of Morgan Hill received bad news this week when two municipal wells tested above the state “action level” for perchlorate and were shut down. The source of the contamination is unknown.
Water from Morgan Hill’s remaining public wells all test non-detect and residents are receiving only water from those wells. In addition, the county health officer, Dr. Martin Fenstersheib, has said that he does not expect harm to come to people drinking water with levels below the action level of 4 parts per billion.
“We don’t know if it’s Olin,” Mike DiMarco, spokesman for the Santa Clara Valley Water District, said about the latest contamination. The Olin plant is the acknowledged source of the perchlorate contaminating hundreds of wells south of Tennant Avenue. The source site is 3,000 feet from the Condit Road well and at least 7,000 feet from the Nordstrom Park well.
The Condit well results showed a level of 5 ppb of the chemical in only one test; Nordstrom showed 6 ppb, also in only one test of several. The Nordstrom well is located on the corner of Murphy and East Dunne avenues in Nordstrom Park. The Condit well is on the corner of Barrett Avenue and Condit Road.
The decision to shut the two wells down Monday was made by Jim Ashcraft, the city public works director.
“The wells showed non-detect in January (Jan. 15), tested positive on February 21 and non-detect again at the confirming test on February 25,” he said.
All current city wells – the city has 13 but two are off line – came back non-detect and have always done so.
In April 2002 the city closed another municipal well because of perchlorate contamination. The Tennant well, located directly across the street from the Olin Corp. site, was closed permanently and a new well dug near the soccer fields on San Pedro Avenue. The public was notified in mid-May, the first public sign of what has become a problem of major concern in South County.
Olin Corp. was presented with a bill for $710,000 covering the cost of drilling the new well; the city and Olin are still negotiating.
The California Department of Health Services requires a second and confirming sample to be taken a month after a detect is found in a water sample. Then the two levels are combined and the water agency acts on that level.
Ashcraft said the regulations instructed them to average the 6 and 5 ppb with the two non-detect levels – zero -– and, if those levels are below the 4 ppb action level – which they were – no action need be taken.
He noted that non-detect does not necessarily mean zero – it just means below 4 ppb.
“Tests that show zero to 3.9 ppb are not reliable,” he said.
The Department of Health Services allows cities to provide customers with municipal water with levels up to 10 times the action level, which in the case of perchlorate, would be 40 ppb. The only requirement is that the customers must be notified by the city.
By shutting down wells with such low levels of the chemical, the city reacted well ahead of state rules.
“These are steps far in excess of the state DOHS requirements,” Ashcraft said. When perchlorate levels are between the action level – 4 ppb – and the maximum contaminate level – 40 ppb – all the city is required to do is notify residents within 30 days.
During a presentation to the City Council Wednesday night, Ashcraft said he intends to request permission at the council’s next meeting – March 19 – to drill a new well as a back-up, in case one or both of the wells cannot be reopened. A new well might be necessary to keep the city from being short of water during the summer months.
“We will keep the wells off line for at least another month,” Ashcraft said.
Conventional wisdom – backed up by geologists and water district engineers – has always held that the water flows south, southeast from the Olin plant and wells north of the source should be safe. All above ground water – streams and creeks – south of Cochrane Road flow south. For underground water – the aquifer – the dividing line is of what is the proposed Cisco site, near Metcalf Road, in Coyote Valley flows south.
“It’s very odd for it to be going up-gradient,” Ashcraft said.
DiMarco said there are possible sources other than Olin.
“There used to be several fertilizer plants in the area,” he said. The plants imported “bulldog soda” from Chile partially composed of sodium perchlorate.
“The source could also be left-over flares or fireworks or even methamphetamine labs,” he said.
Another theory is that the city wells’ pumping action could possibly bring the water north.
Perchlorate is a by-product from the manufacture of rocket fuel and explosive products, including the flares and automobile air bags.
DiMarco noted that United Technologies Corporation used to test rockets at its facility on Metcalf Road, in Coyote Valley, northwest of the city.
“We just don’t know,” DiMarco said.
Ashcraft said he notified City Manager Ed Tewes late last week; Tewes sent an e-mail to the City Council Monday afternoon; the public was notified at Wednesday night’s council meeting.
Gilroy city officials have said testing of that city’s eight municipal wells in November and February came up “non-detect” for the chemical, although it has been found in a monitoring well within a mile of one Gilroy municipal well. The city plans to test its wells at least monthly, if not more frequently.
Since the news that perchlorate had traveled far from the Olin site was announced in mid-January, more than 950 private wells, and those of both San Martin Water District companies, have been tested. Results in so far show two wells with levels of between 40 to 100 ppb, two between 20 to 40 ppb; nine between 10 to 20 ppb and 176 between 4 to 10 ppb.
The original boundaries of suspected perchlorate contamination from the Olin site were Monterey Road on the west, Center Avenue on the east, Tennant Avenue to the north and, at first, Masten Avenue to the south. Those boundaries have expanded south to Leavesley Avenue and east to Foothill Avenue to include newly-found contaminated wells.
Olin is paying to have all wells in the area tested and is providing free bottled water for residents.
In the meantime, several San Martin residents have joined in a class-action lawsuit against the Olin Corp. and others to force health monitoring and treatment. Property values on land with contaminated wells have also been affected.
Up-to-date information on the on-going perchlorate issue is available at www.valleywater.org
