From The Denver Post: Twelve companies may have violated the Safe Drinking Water Act when using diesel fuel to extract oil and gas in 19 states, including Colorado, House Democrats charged Monday. A year-long investigation into hydraulic fracturing — a process used to get oil and gas from deep inside the earth — by the House Committee on Energy and Commerce found oil and gas companies injected 32.2 million gallons of diesel fuel or fluids containing diesel fuel into the ground in 19 states between 2005 and 2009.