(May 24) HINKLEY—A plume of hexavalent chromium permeating the water table beneath Hinkley has grown considerably in the last 36 months, spreading from a 2.5-by-1 mile area to one of roughly 7-by-2.5 miles, according to the final environmental impact report completed pursuant to Pacific Gas & Electric’s state-mandated remediation of the environmental hazard.
That clean-up has been ordered by the Lahontan Regional Water Quality Control Board, which deemed Pacific Gas & Electric responsible for the contamination.
Hexavalent chromium, also known as chromium 6, is a known carcinogen and highly damaging to several organs. California Department of Health guidelines indicate humans should not consume water that has  a total chromium content greater than than 50 parts per billion.
In 1952, Pacific Gas & Electric established a natural gas pipeline that linked the oil and gas fields in Texas and New Mexico with San Francisco, which required pressurization stations at several junctures along that route. Until 1966, Pacific Gas and Electric (PG&E) utilized chromium 6 to control algae and protect against rust in the cooling towers for those compressor stations. Near Hinkley, PG&E had disposed of chromium 6-laden wastewater from the pressurization stations in unlined ponds. Much of the chromium 6 leached into the water table.
In 1994, lawyer Ed Masry filed a multi-plaintiff direct action suit against Pacific Gas & Electric, alleging contamination of drinking water with hexavalent chromium in the area was a direct result of Pacific Gas & Electric’s negligent action.  The case was settled in 1996 for $333 million, at that time the largest settlement ever paid in a direct-action lawsuit in American history. In 2006, PG&E agreed to pay another $295 million to settle cases involving 1,100 people statewide for chromium 6 related claims not involved in the prior suit. In 2008, PG&E settled the last of the cases involved with the Hinkley claims for $20 million. Despite those payouts, the contamination problem at and around Hinkley remains.
Hinkley is slightly north of California State Highway 58, 14 miles northwest of Barstow, 59 miles east of Mojave and 47 miles north of Victorville.
The presence of Chromium 6 near Hinkley again became an issue in 2010  when hydrologists learned the contaminated plume had expanded to roughly 2 1/2 miles in length and about a mile in width.
In 2011, following indications that the plume was still extant and spreading and that many more residents of the area were at risk, PG&E initiated the provision of bottled water to locals and was prepared to commit as much as $54 million toward providing a permanent replacement water supply for all indoor domestic uses, including individual household filtration systems. The Lahontan Regional Water Quality Control Board concluded that merely providing bottled water was not adequate and it ordered Pacific Gas and Electric to provide a new permanent water source to affected users. PG&E dissented from that mandate but lost its appeal. Lahontan called for a more thorough examination of the extent of the contamination and has since called for an aggressive – and expensive – remediation effort. Simultaneously, Pacific Gas & Electric undertook an effort to buy up all of the property in and around Hinkley and encourage those residents remaining there to move away. Such a strategy, PG&E believes, will in the long run prove less expensive than undertaking a cleanup of the aquifer. A substantial number of Hinkley residents have sold their property to the company and have left town, presumably for good.
PG&E has also questioned the standard Lahontan is calling for with regard to chromium 6 levels. PG&E maintains that the standard is more than 100 times lower than the naturally occurring chromium background level in Hinkley and lower than naturally occurring background levels in many other communities in California. PG&E is suggesting the level of water purity Lahontan is requesting cannot be achieved.
PG&E cited a survey completed by faculty and students with the University of California at Berkeley, which found chromium 6’s background level in Hinkley to be 3.1 parts per billion. The company is requesting that Lahontan adopt that as the goal for decontaminating the water. Others, however, are skeptical, pointing out that the background levels PG&E is referencing refer to trivalent chromium, or chromium 3, which is a far less toxic substance than chromium 6.
PG&E previously maintained the level of remediation  that Lahontan is demanding “will result in a material increase” that will endanger the company’s solvency since it will not be able to recover the costs from its customers, and will impact negatively the value of the company’s stock.
Nevertheless, the environmental impact report for the remediation effort now under consideration and which PG&E is now purposed to comply with sets forth a multitude of cleanup alternatives, including  extraction of the contaminated water, carbon filter amendment of the contaminated groundwater and reinjection of the water into the aquifer,  agricultural application of the water within and adjacent to the northern diffuse portion of the plume to metabolically process the water, freshwater injection in the northwest area of the plume adjacent to the western boundaries of contaminated areas, further carbon filtration of and reinjection of extracted water and continuous monitoring of the contamination levels and migration of the plume.