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CH3041
GROUNDWATER
• Groundwater contamination is a major
concern as many aquifers are used as
supplies of raw water for drinking water.
• Aquifers at risk: limestone, sandstones, glacial gravels and sands.
Contaminants: petrol (+ BTX, MTBE) ­ LUSTs,
Leaking Underground Storage Tanks
chlorinated solvents ¯ (dry cleaning in
1,1,1-trichloroethane TCE (1.5kT/y), CCl4),
NO3- (fertilizers, septic tanks)  “blue baby syndrome”
Cr(VI) (tanneries use Cr2(SO4)3 - soluble
•  The organic pollutants
contaminate the soil at the
edge of the aquifer “solvent
blob” and continue to pollute
the aquifer for long periods.
Erin Brockovich   In 1993, Erin and Ed put together over 600 plaintiffs, and partnering with a powerhouse law firm, went after PG&E,
a $30 billion company. As a result of their efforts, PG&E settled with the plaintiffs for $333 million, the largest settlement ever paid in
a direct-action lawsuit in U.S. history.
Pacific Gas &Electricity used water containing chromium 6, Cr(VI), to cool pipes at their Compressor Station in Hinkley, CA.
The tainted water was then discharged into local groundwater supplies and used by local residents. The discharged chromium 6 in
the groundwater attained levels approaching 24 ppm  in the wells which were sampled while the recommended drinking water limit in the US is 5 ppb.
TCE Australian use 2003 – 1.5kT/yr in drycleaning.