More data and research are necessary to best understand the potential risks to water quality associated with unconventional oil and gas development in the United States, according to a recent U.S. Geological Survey study.

“We mined the national water-quality databases from 1970 - 2010 and were able to assess long-term trends in only 16 percent of the watersheds with unconventional oil and gas resources,” said Zack Bowen, USGS scientist and principal author of the article that appears in American Geophysical Union’s Water Resources Research.“There are not enough data available to be able to assess potential effects of oil and gas development over large geographic areas.”

There is not a national water-quality monitoring program in place that focuses on oil and gas development, so existing national water-quality databases and data on hydraulic fracturing were used to assess water-quality trends in oil and gas areas. The study found no widespread and consistent trends in water quality, such as chloride and specific conductance, in areas where unconventional oil and gas wells are prevalent. The amount of water-quality samples, where they are located and the varying constituents that are measured are limiting factors in existing national databases. 

Hydraulic fracturing is presently the primary stimulation technique for oil and gas production in low-permeability, unconventional resource reservoirs. Comprehensive, published and publicly available information regarding the extent, location and character of hydraulic fracturing and potential effects on regional or national water quality in the United States is scarce. More information can be found on the USGS frequently asked questions on hydraulic fracturing.