When approached by Voice reporter Daniel DeBolt, a maintenance worker in Building 10 said employees were told little about the dangers of trichloroethylene (TCE) when the chemical's vapors were found in samples of the building's indoor air last year. A temporary ventilation system quickly solved the problem, but no one knows how long employees were exposed to TCE vapors. The Department of Defense tested 23 buildings at Moffett Field last year in areas where the U.S. Navy is responsible for the pollution cleanup. Two of the surveyed buildings had toxic levels higher than than limits set by the Environmental Protection Agency in areas occupied by workers — the Moffett Field history museum and Building 10, which houses a crew of maintenance workers.
Luckily, the 20 workers who spend time at Building 10 are only there for an hour a day, five days a week, which lowers their risk of becoming ill from breathing TCE vapors. Workers come to pick up their tools and eat lunch, said the person who spoke to the Voice.
But even if most workers only spend one hour a day in a TCE-contaminated building, the Dept. of Defense and NASA Ames owe it to their employees and contractors to warn them if their workplace buildings could or do contain a serious health threat from TCE gas. And in the meantime, these agencies should be moving full-speed on a plan to decontaminate the buildings, using techniques that the EPA has found to be successful.
An analysis of the tests performed last year showed that low levels of TCE was present in many buildings, but not at toxic levels in most locations. But in six buildings at least one test location showed dangerous levels, an ominous sign that would worry most workers if they knew it was present.
Over the last several months the Voice has published many reports about how vapors from the TCE plume are being detected in new locations and at sometimes toxic levels, inside homes and other buildings previously not considered to be at risk. The groundwater under these buildings was contaminated when the Navy's underground solvent storage tanks leaked, according to EPA reports, and employees in various Moffett maintenance shops apparently dumped the solvents they used to clean parts on to the ground, where it seeped into the water table and has been present ever since. It is vapors from this chemical that come up through floors and collect inside buildings. Years of exposure to the vapors of this chemical is known to cause cancer, and the EPA warns that birth defects can result from just days or weeks of exposure at vulnerable times during pregnancy. Many other health problems can result if a person is exposed to toxic levels of vapors from TCE.
Last month the Voice reported about concerns raised by residents of the Moffett Field's Wescoat Village, where resident are concerned about living over contaminated soil and groundwater.
"Many of us feel we have been living here uninformed with regards to the nearby plume," a resident wrote in a letter shared with the Voice.
"Being notified of issues potentially so dangerous should be as mandatory as having to supply the front office with the required copy of my pet's vet records to ensure they are safe to be in housing," said one Wescoat resident, whose online post was made available to the Voice.
Presence of the toxic TCE plume has been known to Moffett officials and the EPA for nearly 30 years. Nevertheless, residents or people who work in Moffett buildings, as well as certain neighborhoods in Mountain View, often are in the dark about the underground threat. The EPA, NASA Ames and the military need to take a much more aggressive stance on making sure workers and residents are warned about the potential hazard under their feet. Government agencies should not wait until the last minute to issue warnings when toxic quantities of TCE is found in their homes or workplaces.