The Coloradoan reports that civil and environment engineering professor Ken Carlson led studies analyzing the impact of oil and gas drilling on groundwater in the 6,700-square-mile Denver-Julesburg Basin.
More than 30,000 active or abandoned wells for oil or natural gas sit on the basin.
Carlson says there is not a "chronic, the-sky-is-falling" problem with water contamination.
The study did find, however, that 2 percent of sampled wells showed the presence of methane. Methane can be explosive, but the university says it's not toxic and not a huge factor in terms of drinking water safety.
The team didn't find bariums, chromiums or other dangerous soluble contaminates.