Hinkley Hexavalent chromium

hexavalent chromium found in drinking water in southern california town of hinkley , brought popular attention involvement of erin brockovich , attorney edward masry. source of contamination evaporating ponds of pg&e (pacific gas , electric) natural gas pipeline compressor station located approximately 2 miles southeast of hinkley. between 1952 , 1966, chromium(vi) used prevent corrosion in cooling stacks. wastewater dumped unlined evaporating ponds. result, chromium(vi) leaked groundwater source. 580 ppb chromium(vi) in groundwater in hinkley exceeded maximum contaminant level (mcl) of 100 ppb total chromium set united states environmental protection agency (epa). exceeded california mcl of 50 ppb (as of november 2008) types of chromium. california first established mcl hexavalent chromium in 2014, set @ 10 ppb. prior total chromium standards applied.

a more recent study found 1996 2008, 196 cancers identified among residents of census tract included hinkley — lower number 224 cancers have been expected given demographic characteristics. in june 2013 mother jones published article regarding work center public integrity critical of study, , others same researcher, john morgan. comes in contrast conclusions reached epa , california’s department of public health chromium(vi) in fact cause cancer.

at time pg&e background study of chromium(vi) conducted, average chromium(vi) levels in hinkley recorded 1.19 ppb peak of 3.09 ppb. pg&e topock compressor station averaged 7.8ppb , peaked @ 31.8ppb. california mcl standard still @ 50 ppb @ completion of background study. in comparison, office of environmental health hazard assessment (oehha) of california epa, proposed health goal of 0.06 ppb of chromium(vi) in drinking water in 2009. in 2010, erin brockovich returned hinkley in midst of claims plume spreading, despite pg&e cleanup efforts. pg&e continues provide bottled watered residents of hinkley offer buy homes. other ongoing cleanup documentation maintained @ california epa s page.