The residents have faced concerns over hexavalent chromium in their well water from the world's largest plume of this cancer-causing chemical.

Residents of Hinkley eventually filed a class action lawsuit against Pacific Gas and Electric Company (PG&E).

[3] In 1993, Erin Brockovich, a legal clerk to lawyer Edward L. Masry, investigated the apparent elevated cluster of illnesses in the community linked to hexavalent chromium.

The case was settled in 1996 for US$333 million, the largest settlement ever paid in a direct-action lawsuit in United States history.

In 2006, PG&E agreed to pay $295 million to settle cases involving another 1,100 people statewide for hexavalent chromium-related claims.