A poisonous plume of Hexavalent Chromium-laced groundwater is still spreading near Hinkley, CA, violating a long-standing order for Pacific Gas and Electric Co. (PG&E) to clean up the contamination, local water officials have found.
The contamination, 12 miles west of Barstow in the Mojave Desert, was the subject of the 2000 movie Erin Brockovich, which profiled the efforts of a California paralegal to gain compensation for sickened residents against California’s largest utility.
PG&E used Hexavalent Chromium (also known as Cr(VI) and Chromium 6) from 1952 to 1966 to fight corrosion in cooling tower water. The wastewater from the cooling towers was discharged to unlined ponds at the site, according to the Lahontan Regional Water Quality Control Board, which oversees the area.
Some of the wastewater percolated to the groundwater, resulting in Chromium 6 pollution of an area of groundwater that is about two miles long and nearly a mile wide, the Water Board found.
“Recent chromium plume migration to the northeast of the Desert View Dairy has been detected,” the board announced in a press release Friday (Nov. 5). “This plume migration violates a Cleanup and Abatement Order requirement to maintain control of the plume.”
The Water Board also demanded that PG&E conduct additional investigations “to determine the extent of elevated chromium concentrations” detected elsewhere in the area.
The Water Board ordered PG&E in August 2008 to clean up the plume by the end of that year. Nevertheless, the plume has expanded by more than a half-mile in that time.
The Water Board voted July 14 to allow additional groundwater extraction in the area to address the new contamination.
Despite the new finding, the board issued no penalty against PG&E, saying a “verbal enforcement action” was sufficient because the utility had been cooperative. The Water Board did not respond to a request for comment Tuesday (Nov. 9).
In August, PG&E released a feasibility study to outline the alternatives for a final groundwater remedy. The 64-page study said the utility had made “significant progress” in containing the plume.
The document proposed a plan to inject groundwater northwest of the Hinkley Compressor Station plume to contain it. The report said modeling had shown that this strategy would provide “robust hydraulic influences over the plume boundaries and is anticipated to effectively contain the plume.”
Additional Wells Tainted
However, increased levels of chromium have recently been detected in about 12 domestic drinking-water wells, in addition to dozens of others previously found to be affected, the Water Board’s senior engineering geologist told the San Francisco Chronicle.
Geologist Lisa Dernbach also told the newspaper that Chromium 6 had also been found in what she called "the lower aquifer," an area of groundwater separated from the upper aquifer by a layer of clay and previously thought to be uncontaminated.
Utility Asserts Safety
PG&E also declined to comment Tuesday, but a utility spokesman told the Chronicle that the Chromium 6 levels in the new area had not exceeded the state’s safe drinking water standard and had been reduced to natural background levels.
The utility was ordered to clean up the water after the lawsuit led by Brockovich. A 1993 suit by 650 Hinkley residents ended with a $333 million settlement. Many of the residents had fallen sick or had died from breast cancer, Hodgkin's disease, lung, brain and gastrointestinal cancers, miscarriages, or kidney and ovarian tumors allegedly caused by exposure to the toxic water.
At one point in the case, a consulting firm hired by PG&E was found to have distorted data from a Chinese study to plant an article in a scientific journal reversing the study's original conclusion that linked an industrial chemical to stomach cancer, according to documents obtained by Environmental Working Group (EWG).
Other lawsuits involving 1,100 people exposed to Chromium 6 from PG&E facilities in Kings, Riverside and San Bernardino counties were also settled, the last one for $20 million in 2008, the Chronicle reported.