Contamination source remains a mystery
A new federal report detailing perchlorate contamination in Salinas has some environmentalists pointing fingers at Olin Corp., but water experts from around the region say that it’s highly improbable that Morgan Hill’s perchlorate plume has traveled that far south.
“It’s next to impossible to see a connection,” said Mike DiMarco, a spokesman for the Santa Clara Valley Water District. “We know where the southern and northern edges of the plume are.”
But the source of contamination remains a mystery. On Monday, the federal Food and Drug Administration revealed that it had discovered perchlorate in lettuce and milk in each of the 15 states that it tested. Several of the sites, including Salinas, have no known source of contamination.
That, says Bill Walker of the Environmental Working Group in Oakland, proves that the “source in Morgan Hill is reaching to Santa Cruz and Monterey and contaminating the lettuce. It’s an eye-opener.”
But David Athey, who handles the Morgan Hill and San Martin site for the state Central Coast Regional Water Quality Board, said there are several possible sources, including rocket fuel, road flares, perchloric acid, a natural fertilizer that comes from Chile, and perhaps even lightning.
“People have a tendency to point fingers, but you need to do an investigation to figure out what you’ve got,” Athey said. “You start with a theory and try to prove or disprove it. You don’t start with an answer and try to make it fit.”
The contamination levels in Salinas lettuce range from 1 to 29.6 parts per billion. Some samples of Iceberg, Romaine, Red Leaf and Green Leaf lettuces showed no perchlorate.
California has set a standard of 6 ppb in the state’s drinking water. An imminent report from the National Academy of Sciences is expected to set a nationwide standard.
Bob Nielsen, senior vice president of Tanimura and Antle, one of the largest private farming operations in the country and major lettuce producer in the Salinas Valley, said Thursday that the report will have no effect on operations.
“To us, this is really a water quality issue that affects the whole country,” he said. “To my knowledge, no farmers are doing the kind of testing done by the FDA because it’s too specialized and too expensive.”
The FDA study says that lettuce samples were retrieved from growers and packing sheds, but it’s not clear if any of the lettuce came from Tanimura and Antle fields. According to Nielsen, there are rumors that the agency bought the lettuce in supermarkets, or maybe even picked it straight out of the ground, leaving farmers unaware if their produce is tainted.
In Morgan Hill, City Manager Ed Tewes announced Wednesday, Dec. 1, that, in the city’s monthly testing for perchlorate, all city wells showed nondetect. No well has perchlorate levels above 4 parts per billion, the level at which the city shuts down a well. At 6 ppb the state requires only that customers be notified.
The Nordstrom and Tennant wells, that had shown higher levels in the past have ion exchange treatment systems installed; their perchlorate levels were also nondetect.
The report may be read at www.cfsan.fda.gov/~dms/clo4data.html/#table1.
Matt King covers Santa Clara County for The Times and The Dispatch. He can be reached at 847-7240 or mk***@************ch.com
