PG&E poisoned a town's water with chromium — $333M class-action settlement

From 1952 to 1966, Pacific Gas and Electric Company (PG&E) used hexavalent chromium (chromium-6) as a rust suppressor in cooling towers at its compressor station in Hinkley, California. The company dumped approximately 370 million gallons of chromium-tainted wastewater into unlined ponds, allowing the toxic chemical to percolate into the groundwater aquifer that supplied the town's drinking water.

In 1987, PG&E informed the local water board of the contamination, but the full extent was not publicly known until 1993, when Hinkley resident Roberta Walker noticed foaming tap water and hired attorney Edward L. Masry. Masry's legal clerk, Erin Brockovich, investigated and discovered that PG&E had known about the contamination for years and had offered to buy homes from affected residents with no disclosure of the reason.

Brockovich organized the community into a class-action lawsuit, Anderson, et al. v. Pacific Gas and Electric. The case settled in 1996 for $333 million — the largest class-action settlement in U.S. history at the time. The case was dramatized in the 2000 film Erin Brockovich, starring Julia Roberts, which won the Academy Award for Best Actress.

PG&E spent over $750 million on remediation, plus additional settlements of $295 million in 2006 for 1,100 claimants statewide and $20 million in 2008 for remaining Hinkley claims. The case led California to establish a maximum contaminant level for hexavalent chromium of 10 parts per billion in 2014. It also exposed PG&E's pattern of environmental negligence — the company later filed for bankruptcy in 2019 due to $30B+ in wildfire liabilities.