Hinkley groundwater contamination

From 1952 to 1966, Pacific Gas and Electric Company (PG&E) dumped about 370 million U.S. gallons (1.4×109 liters) of chromium-tainted wastewater into unlined wastewater spreading ponds around the town of Hinkley, California, located in the Mojave Desert about 120 miles (190 kilometers) north-northeast of Los Angeles. PG&E used chromium 6, or hexavalent chromium (a cheap and efficient rust suppressor), in its compressor station for natural-gas transmission pipelines.

Source: Wikipedia — Hinkley groundwater contamination (CC BY-SA 4.0)