Federally Funded Study Blames Poor Construction for Gas Contamination.

Natural gas is contaminating some aquifers not from hydraulic fracturing but from faulty well preparation, according to a new paper. Poorly built and cemented gas wells, rather than fracking itself, have allowed contaminants to flow into shallow drinking-water sources, according to a report published in the Proceedings of the Natural Academy of Sciences. A debate has raged for years over whether the U.S. energy boom is fouling aquifers and water wells—and what can be done about it. Researchers reported Monday that they developed a tool that can identify whether underground gas has migrated toward the surface over time, or whether it moved recently and rapidly up an industry-drilled well or the cement surrounding the well pipe. Fracking involves pushing a slurry of water, sand and chemicals down a well to break up dense rocks and coax more fuel from the ground. Many academics and some industry engineers have long argued that when contamination occurs, it is the result of bad well construction not the fracking process. Others in the energy industry have maintained that natural gas has been found in aquifers and water wells for years and that there is no proof that fracking or other drilling has made it worse. "Where contamination occurs, it related strictly to well integrity," said study co-author Thomas Darrah, an assistant professor at Ohio State University. "The answer is not to stop drilling. The fix is better executions on the construction of the well and improving well integrity." He said evidence of contamination didn't correlate to wholesale leaks caused by fracking.

More From The Wall Street Journal (subscription required):