Groundwater contamination in Hinkley, California Pacific Gas and Electric Company

from 1952 1966, pg&e dumped 370 million gallons of chromium 6-tainted wastewater unlined wastewater spreading ponds around town of hinkley, california. pg&e used chromium 6— 1 of cheapest , efficient commercially available —at compressor station plants in cooling towers along natural gas transmission pipelines.

pg&e did not inform local water board of contamination until december 7, 1987, stalling action on response contamination. residents of hinkley filed successful lawsuit against pg&e in company paid $333 million— largest settlement ever paid in direct-action lawsuit in u.s. history. legal case, dramatized in 2000 film erin brockovich, became international cause célèbre. in response, in 2001, @ request of calepa, chromate toxicity review committee formed investigate toxicity of chromium-6 when ingested. in 2003 senate hearing revealed committee s supposedly blue-ribbon members included pg&e defense expert witnesses had influenced final august 2001 report found in pg&e s favor concluding other reports alarmist spuriously high statistics , further evaluation should handled academics in laboratory settings not regulators. through time report recanted set regulation of chromium 6 many years. in july 2014 california became first state acknowledge ingested chromium-6 linked cancer , result has established maximum chromium-6 contaminant level (mcl) of 10 parts per billion (ppb). in setting regulations acknowledged in recent scientific studies in laboratory animals, hexavalent chromium has been linked cancer when ingested. previously, when older chromium mcls set, @ time total chromium mcls established, ingested hexavalent chromium associated consumption of drinking water not considered pose cancer risk, case.

by 2013 pg&e had cleaned 54 acres, estimated remediation process take 40 years. pg&e built concrete wall barrier half-mile-long contain plume, pump ethanol ground convert chromium-6 chromium-3, , have planted acres of alfalfa. created chicken farm use alfalfa. pg&e uses irrigation maintain these large circles of green in otherwise desert area, , asked stop because of ongoing danger of residents inhaling chromium 6.

in 2015 california regional water quality control board, lahontan region served pg&e new order cleanup [sic] , abate effects of discharge of chromium waste or threatened pollution or nuisance. time of report plume had expanded 8 miles in length , approximately 2 miles in width, throughout hinkley valley , harper dry lake valley , polluting new areas. in 2016, new york times described hinkley having been turned ghost town due contamination of area owners unable see properties.

epidemiologist john morgan produced 2010 report california cancer registry in argued there no cancer cluster in hinkley related chromium 6. in 1 study morgan had claimed cancer rates in hinkley remained unremarkable 1988 2008 saying 196 cases of cancer reported during recent survey of 1996 through 2008 less expect based on demographics , regional rate of cancer. in 2013 center public integrity found glaring weaknesses in morgan s 2010 analysis challenged validity of findings. in first study, dismisses others see genuine cancer cluster in hinkley. in latest analysis, excludes people exposed worst contamination.