Chief Oil & Gas LLC announced Thursday that separate investigations by the company and the Pennsylvania Department of Environmental Protection (DEP) have concluded that Chief is not responsible for contaminating the water well of a woman in Bradford County, PA, who went on to become a vocal critic of hydraulic fracturing (fracking).

Crystal Stroud, a resident of Granville Summit, in April accused the company's Marcellus Shale activities with contaminating her well with high levels of barium and lead, and for causing her and her family health problems.

"While Chief strongly believed its operations were unrelated to Ms. Stroud's claims -- and no evidence had been provided by Ms. Stroud to validate her allegations -- Chief met with Ms. Stroud, sampled her well and then subsequently launched a full investigation to determine the cause of contamination," the company said late Thursday.

The Dallas-based company said that in January it drilled a surface hole to a depth of 360 feet at the Andrus wellsite near Stroud's property. The well was drilled using compressed air and no drilling mud was used.

None of the metals or chemicals found in Stroud's well water went into or came out of the well during the drilling process. Chief said that before any further drilling occurred, the surface hole was properly cased and cemented, isolating and protecting the ground water.

Water samples were taken from other wells in close proximity to the Andrus site prior to drilling, and then again after receiving Ms. Stroud's complaint. These samples yielded no meaningful changes in water quality, Chief said. Chief said it found barium and other substances mentioned by Ms. Stroud, but only in trace amounts well below the maximum contaminant level (MCL) requirements of the U.S. Environmental Protection Agency (EPA), both before and after drilling.

Chief said independent experts had concluded that the chemicals found in Stroud's well "have been naturally present in the ground water in this area for quite some time...long before any Marcellus drilling in the area," and cited a 1998 report by the Pennsylvania Department of Conservation and Natural Resources (DCNR), which came to the same conclusion.

"It is likely that Ms. Stroud's well water has had the levels of barium and other substances she reported since the day she moved into this residence," the company said.

Chief said the DEP's investigation had come to the same conclusion, and said the agency sent a letter to Stroud saying its investigation "indicates that the conditions documented in your water well reflect background conditions [that were] preexisting and that gas well drilling has not impacted your water supply."

Chief and its partners once held close to 650,000 net acres of leasehold in the Marcellus but they have been selling much of it. In May Chief and Tug Hill Inc. sold 228,000 net acres to Chevron Corp. for an undisclosed amount (see Shale Daily, May 5). Chief currently holds a Marcellus Shale acreage position of 125,000 net acres, which includes Pennsylvania, New York and West Virginia. The company is currently permitted for 232 Marcellus Shale gas wells in Pennsylvania.