Natural gas and oil operations were not the cause of groundwater contamination in the Pinedale Anticline that was identified seven years ago and has been under investigation since then, according to two new Bureau of Land Management (BLM) reports released last Wednesday.

The contamination has been mitigated and for the most part was related to naturally occurring seepage and water well drilling, according to the reports.

BLM indicated it will use data from the reports to draft new plans for monitoring groundwater and mitigating any problems in the future.

An environmental group official in the area told local news media she was not 100% confident of the findings, but BLM's Merry Gamper, a fluid minerals and physical scientist specialist, said she thinks the conclusions are "sound" and offered "good results for us."

Gamper and BLM held an annual planning meeting last Friday in the Pinedale field office on the Supplemental Environmental Impact Statement and Record of Decision to discuss the results of the latest reports and a related study.

The reports carry the imposing titles of "Evaluation of Potential Sources of Low Level Petroleum Hydrocarbon Compounds Detected in Groundwater" and "Numerical Groundwater Modeling." A third complementary report cited by BLM, "Hydrogeological Data Gaps," discusses regional aquifer characteristics that include general water quality, flow gradients, the basin water budget and surface water/groundwater.

Gamper made a number of recommendations to the Pinedale office based on her review as BLM's lead scientist on the ongoing Interim Groundwater Mitigation Plan, concluding that "there is no widespread contamination occurring from oil/gas operations on the Pinedale Anticline."

Linda Baker, an official with the Upper Green River Alliance, said that she has questions about BLM's methodology and whether it had pinpointed the sources of the groundwater contamination.

A spokesperson for the Wyoming Department of Environmental Quality (DEQ) said that since 2006 most of the wells have cleared up. Eight wells remain in the state's voluntary remediation program. Four of those have been cleaned, one is in active clean-up operations, and three are under evaluation.

Some of the major operators in the area -- units of Royal Dutch Shell, Ultra Petroleum Corp. and QEP Resources -- issued a joint statement reiterating that the study proves that groundwater in the region is safe.

"Industry practices are in place to protect groundwater, and this has been validated by the study, and we will ensure that practices continue to protect groundwater into the future," the operators said.

In the past the federal Environmental Protection Agency (EPA) and BLM have butted heads over the latter agency's willingness to approve more gas operations in the Pinedale area (see Daily GPI, Feb. 21, 2008). BLM is cooperating with the state DEQ and EPA's Region 8 office and the operators in the Pinedale gas development program on groundwater monitoring programs in the area.