GREEN RIVER - The Bureau of Land Management on Friday released a long-awaited, revised environmental study that calls for dramatically expanding natural gas drilling in the Pinedale Anticline field in western Wyoming.

The BLM's management plan calls for increasing the level of development by drilling almost 4,400 new producing wells, while at the same time relaxing seasonal drilling restrictions that aim to protect wildlife, which will allow for year-round access in certain areas of the field.

The final drilling plan also calls for new air pollution controls to help assuage local residents' concerns that energy development in the field is causing spikes in air pollution and ozone counts.

But conservationists panned the study Friday and said the BLM acknowledges in the document that ozone levels will exceed federal standards in the near future and that air quality in Pinedale will get worse before it gets better.

The proposal was submitted by the three primary energy operators in the field - Questar Exploration and Production Inc., Shell Exploration and Production Inc., and Ultra Petroleum Inc.

The companies contend the long-term proposal is an innovative approach to balancing the nation's energy needs with the development of natural resources on the Anticline.

The companies want to relax drilling restrictions that aim to protect big game animals, upland birds and wildlife habitat in order to tap into an estimated 20 trillion to 25 trillion cubic feet of natural gas.

The plan calls for increasing development, from the 1,139 wells now authorized under the agency's 2000 management plan for the Anticline to 4,399 wells.

The new wells would be drilled from 250 new well pads and from the expansion of existing well pads, according to the document.

There are currently more than 642 producing oil and gas wells on 340 well pads within the field. Once development is complete in 2023, the BLM estimates, there would be 590 total well pads in the Anticline.

The new plan would also bump up the amount of surface disturbance, which is expected to run through 2023, from about 4,400 acres to 12,885 acres.

Bruce Hinchey, president of the Petroleum Association of Wyoming, said the companies are committed to reducing "their footprint" in the field, which is reflected in the number of wells planned for drilling vs. the number of actual well pads.

"It's a resource that's drastically needed … Prices are at record levels, and hopefully this will help meet the energy needs for the nation," Hinchey said in a phone interview. "Year-round drilling is also something that's been needed, and it's been shown that it will work."

The Anticline is the second-largest natural gas field in the United States. The 198,000-acre field is located in Sublette County and is estimated to contain enough natural gas to supply 15 million homes for 20 years.

Federal officials said the royalties over the life of the plan from the production of natural gas would generate about $16 billion, with almost $8 billion going to Wyoming. The BLM estimated that the new wells would have a 40-year production life continuing through 2065.

The supplemental environmental impact statement's preferred plan calls for year-round development within big game crucial winter habitats in three "concentrated development areas" within a "core area." Current restrictions on drilling in the Anticline generally run from Nov. 15 to April 30 in order to protect big game animals such as mule deer, elk and antelope, sage grouse and wildlife habitat.

The document identifies three new pipeline corridors that would contain gas sales pipelines. The operators would install a liquids gathering system in the central and southern portions of the field to complement an existing system in the northern portion. An expansion of the Granger Gas Processing Plant is also planned to handle the increased production.

Ozone concerns

Area residents expressed concerns about air quality in the region after Wyoming's Department of Environmental Quality issued a series of ozone advisories for the Pinedale area this winter, warning residents about unhealthy ozone spikes.

Residents tied those unhealthy levels to energy development in the Upper Green River Basin. Ground-level ozone pollution is a chief component of smog and can cause potentially serious respiratory problems in people and animals.

The federal study said once year-round drilling access is granted, the companies would employ a host of strategies and procedures in an effort to further reduce air pollution.

The companies plan to implement stricter equivalent emissions technology on all of their new drilling rig engines, for example, and to construct the low-impact liquids gathering systems, which would reduce the amount of truck traffic to and from well pads.

Jared White with the Bozeman, Mont.-based Wilderness Society said the BLM has failed in the past to monitor nitrogen oxide pollution emissions, which contributed to the record ozone levels this past winter.

He noted that emission controls to help stem dangerously high ozone levels would be installed on drilling rig engines on just 29 of 48 rigs during peak drilling in 2009 under the companies' proposal.

White said if the BLM makes any changes to address air and water pollution, the public needs the opportunity to review the changes through a draft environmental impact statement, not a final EIS.

"Without their input, local citizens have every reason to be skeptical of a final version at this point," he said.

"The last time the BLM issued a final decision for the Pinedale Anticline, they ended up breaking enough promises to warrant a recent lawsuit," White said, referring to a lawsuit filed June 17 by the Theodore Roosevelt Conservation Partnership over the BLM's lack of accountability for protecting wildlife resources in the Anticline. "Now, they are offering up a new set of promises, but locals aren't buying it."

Shell senior communications adviser Deena McMullen and Questar communications specialist Emily Fisher said in a joint release with Ultra on Friday that the companies are pleased to have reached the "milestone" of the new environmental document.

"We are committed to helping our country efficiently and responsibly meet its energy needs, which is why we are investing in a long-term management plan … that will help us continue to conserve the environment and increase benefits for local communities," the e-mail said.

Company officials said in order to provide "more predictability" during the development phase, they are proposing to institute a 10-year "rolling forecast or development plan" with the BLM and state wildlife officials.

Each year under the plan, the companies would review the development strategies with the agencies and make modifications in a further attempt to reduce impacts.

Gov. Dave Freudenthal's press secretary, Cara Eastwood, said Friday said the governor's office was in the process of reviewing the environmental analysis. "We haven't had a real chance to read the document yet," she said.

Southwest Wyoming bureau reporter Jeff Gearino can be reached at 307-875-5359 or at gearino@tribcsp.com.