September 5, 2010 - New oil and gas drilling is probably the most visible activity people associate with threats to groundwater in Texas. But it's not usually the source of known contamination, according to state records.
Instead, old or abandoned oil and gas wells, petroleum storage facilities and even existing water wells are most frequently identified as problems.
A Texas Groundwater Protection Committee report, presented to the Legislature last year, said there were 4,729 active groundwater contamination cases documented or under enforcement in 2008.
Of those, 395, or 8.4 percent, were "attributed to oil and gas exploration and production activities," but "no producing oil and gas wells" were listed as groundwater-contamination sources, Texas Railroad Commission spokeswoman Ramona Nye said. The state has more than 281,000 oil and gas wells, Nye said.
Most contamination attributed to oil and gas exploration and production activities resulted from releases from sources such as pipelines and storage tanks, she said.
Cary Betz, chairman of the groundwater protection committee and a groundwater specialist with the Texas Commission on Environmental Quality, said the biggest source of groundwater contamination is leaking underground gasoline storage tanks at old service stations. But the number of those tanks has dropped significantly, to 1,214 in 2009, he said.