Thirty-five years ago, the Palo Alto Times ran a story headlined "Scores of fish killed by chemical spill in creek." It was a sign of the times -- and may help explain mysteriously high concentrations of toxics found on Evandale Avenue and Leong Drive.
The 1978 story reported that 100 dead fish were pulled from Stevens Creek in Mountain View after a spill of acid from Fairchild Semiconductor's manufacturing plant on Whisman Road. The spill found its way to the creek through a storm drain. The next day, the paper reported that a separate "accident" at Fairchild dumped 2,500 gallons of hydrochloric acid down the sanitary sewer system, which flowed to a sewage treatment plant in Palo Alto.
Such dumping was probably common in those days, says Lenny Siegel, director of the center for Public Environmental oversight in Mountain View, and may be the reason why the EPA is finding surprising levels of Trichloroethylene (TCE) under residential areas near the old Fairchild plant -- under Evandale Avenue and Leong Drive, along sewer lines that may have leaked.
"In the '80s I remember people telling me sewage pipes were eaten up by chemicals," Siegel said of talks with a former city employee familiar with the situation. Unfortunately, Siegel believes the city records were destroyed which could help prove this.
Through the 1960s, '70s and '80s, the early manufacturers of silicon chips in Mountain View on and around Whisman Road included Intel, National Semiconductor, Raytheon and Fairchild. Used in the highly chemical process of silicon chip making, thousands of gallons of toxic chemicals were kept in underground storage tanks, which often leaked into the groundwater as well. The companies left behind a massive groundwater plume of toxics that has been undergoing a major cleanup since the late 1980s, with nearly 100,000 pounds of toxics removed.
"What would you do -- back in those days -- before you knew about all these problems?" Siegel said of the alleged practice of dumping chemicals down the drain. "That was the safe thing to do."
The consequence of the newly discovered contamination on Evandale Avenue is that late last year two homes were discovered to have elevated levels of TCE vapors trapped in the indoor air having risen from the contaminated soil and groundwater. Both homes now require the installation of special ventilation systems to keep the vapors out, as inhaling TCE vapors over long periods can cause "hepatic, renal, neurological, immunological, reproductive, and developmental effects" as well as cancer, according to a 2011 Environmental Protection Agency report.
The EPA's investigation into the source of the contamination is on hold because of the ongoing federal government shutdown, Siegel said. A phone call to the EPA's Alana Lee was not returned.
In march, EPA official Penny Reddy told a large crowd at a neighborhood meeting that the groundwater samples taken every 100 feet along Evandale Avenue were "puzzling, curious" and could be the result of "dumping something down a drain or falling off a truck, we don't know what the source is at this point."
The biggest hot spot was found in front of the 200 block of Evandale Avenue, where 130,000 parts per billion of TCE was found in the groundwater about 13 feet down the same level as the sewer line under the street. To put the amount in perspective, the concentration is 26,000 times higher than the EPA's cleanup goal of 5 parts per billion, and it is higher than any concentration currently found in the larger nearby plume.
"The responsible parties argue that it was midnight dumping," Siegel said of the polluters. "If it was midnight dumping, they are the most likely parties to have conducted it. Somebody who worked for them who was just trying to get rid of a barrel or a can. That doesn't take them off the hook. There wasn't an electronics plant on the residential side of Whisman Road."
Siegel believes that a leaky sewer line or storm drain may also be to blame for the contamination found under and just west of Leong Drive, where concentrations are as high as 12,000 parts per billion. The EPA is still investigating that, and promised to do indoor air sampling of the nearby homes, though there was no indication that the contamination reached any homes.