GILLETTE - Internal Bureau of Land Management e-mail correspondence leaked to an environmental group suggests federal regulators may have considered barring the general public from the Jonah gas field - which lies on federal lands - due to air quality concerns that would arise from intensified natural gas development.

The correspondence also suggests that the size and scope of the Jonah Infill Drilling Project has changed significantly from the original proposal of 1,250 wells, and that a new public scoping process might be in order.

The Wyoming Outdoor Council said the discussion reveals the serious consequences of high-density development, and that a smaller scale project over a longer period of time might avoid significant impacts to the air, wildlife and recreational opportunities in the area.

BLM officials, on the other hand, say that nothing should be taken from the correspondence. No matter how many wells are allowed, the BLM will make sure national and state air quality standards are met, officials said.

Carol Kruse, BLM Pinedale Field office project manager, said the internal correspondence discussing air quality was merely "speculation."

"We haven't done our air quality monitoring yet. That was pure speculation on the part of the contractor (TRC Mariah Associates Inc.)," Kruse said Thursday. "It's not something we're considering. It's not something anybody has suggested."

WOC Executive Director Dan Heilig said he believes discussion in the BLM internal e-mails suggest that the proposal being considered could indeed push the area toward breaching state and national air quality standards, a scenario that could be avoided.

"One fundamental question is whether infill drilling is necessary to fully exploit the gas resource," Heilig said. "Maybe production could be extended out at the existing density over a longer horizon."

Heilig added that infill drilling is one way for the oil and gas companies to get a quick return on their investment.

"I think they're anxious to remove as much gas as quickly as possible from the field rather than having it come at a more moderate level over a longer period," he said.

Kruse did say that development scenarios for the Jonah Infill Project continue to grow. Under the current proposal, EnCana Oil & Gas and BP America want to increase a 497-well project to 1,250 wells. "Infill" means to drill more wells within the same surface boundary.

That proposal convinced the BLM to prepare models for as many as 3,100 wells. Now, industry is hinting that it might ask for even more intense drilling, Kruse said.

"We've gotten word that we are going to get a revised proposed action from the operators," Kruse said.

If a revised proposed action is submitted, the BLM must begin a new scoping process. Regardless, BLM officials plan to have a public meeting in November to discuss the alternatives being developed for the project.

"Because of the tremendous increase in the pace of development we've seen down there, we are doing something a little different with the alternatives and we want to take that to the public before we close the book on them," Kruse said.

In considering an oil and gas development proposal, the BLM must plan to keep certain air pollutants in check with the National Ambient Air Quality Standards and the Wyoming Ambient Air Quality Standards. Those standards include thresholds for "criteria" pollutants including particulates, lead, nitrogen oxide, sulfur dioxide and carbon dioxide.

The pollutants can come from many oil and gas-related activities, such as compressor station engines, diesel-burning equipment, flaring and fugitive releases. Caplin said dust particulates from construction and traffic must also be mitigated.