By Cody Kraat/Sunnyvale Sun
Sunnyvale's groundwater is polluted with chromium 6, a carcinogenic heavy metal, according to a 2007 Water Quality Report released by the city in 2008.
The average concentration in the city's seven wells — 1.4 parts per billion — is considered to be a very low dose and poses little danger, experts said. Chromium 6, also known as hexavalent chromium, was made infamous by the movie Erin Brockovich and a series of articles in 2000 about findings of chromium 6 in San Fernando Valley groundwater at levels as high as 30 ppb.
Sunnyvale residents receive 7 percent of their water from the wells, two of which in the southwest part of the city had concentrations between 2.2 and 3.1 ppb in 2002, in the most recent testing available. The tests were conducted in 2002, and the levels are considered to be below state and federal regulations.
However, the state has no specific standard for chromium 6.
The California Department of Public Health, which is responsible for regulating water quality, allows 50 ppb of total chromium, which includes chromium 6 and trivalent chromium, a harmless and somewhat beneficial nutrient. The U.S. Environmental Protection Agency allows 100 ppb of total chromium.
The CDPH was required according to a section of the state Health and Safety Code to establish a primary drinking water standard — a maximum contaminant level — for hexavalent chromium on or before January 2004, , but the CDPH points the finger at the state Office of Environmental Health and Hazard Assessment for the delay in scientific research. Sam Delson, and OEHHA spokesman, called the history of efforts to create standards "long and complicated." Read more