Chromium 6 in Hinckley's Groundwater

From 1952 to 1966, PG&E dumped 370 million gallons of Chromium-6 filled water into unlined ponds and created a plume of contaminated groundwater about two miles long and one mile wide. Over that time, Hinkley had an inexplicable rise in birth defects and illnesses. Some Hinckley residents believed PG&D knew of the contamination as early as 1965 but told no one. So on December 7th, 1987, PG&D discovered... Chromium had entered Hinckley's groundwater supply in 10 private wells.