While Congress squabbles with Interior Secretary James G. Watt over his plans for developing wilderness lands, his Bureau of Land Management has done what it can to speed the release of its acreage now under study for wilderness designation.

Last Sunday, Watt announced he would submit legislation to bar mineral leasing in all federal wilderness areas until the year 2000. But Watt's proposal, introduced in the House Wednesday by Rep. Manuel Lujan Jr. (R-N.M.), would allow Interior to open up lands now under study for designation as wilderness without having to seek congressional approval. That prospect has raised the hackles of environmentalists and many members of Congress.

BLM's new policy--published in the Federal Register Feb. 3--will speed the process of getting wilderness decisions before Congress. The policy, a major revision of a draft completed at the end of the Carter administration, does not require congressional approval.

Under the new policy, environmental impact statements are no longer required for individual wilderness areas but rather will be prepared on a statewide basis. The policy also sets accelerated deadlines and trims paperwork requirements.

In addition, the department will no longer require mineral assessments for areas recommended to Congress as "unsuitable" for wilderness designation--a decision that was opposed by oil and mineral interests. Pointing out that the assessments are required by law, they argued that the assessments are needed so that developers can tell whether the areas are worth developing. But Interior countered that the cost of the assessments is expected to double from the current $5 or $6 an acre by 1984.

Under the new BLM policy, some of the areas found unsuitable for wilderness designation could be forwarded to Congress for release as early as October. Lands proposed for wilderness designation could not reach Capitol Hill before 1985 because mineral evaluations will still be required for them.

At stake for oil, gas and hard-rock mineral developers are subsurface rights to the 24.34 million acres of BLM land now under study. About 12,000 BLM acres are already part of the nation's 80-million-acre wilderness system. Most of the rest of BLM's 398-million-acre domain is open for leasing.

Currently, all study areas are managed as wilderness, guarded by strict environmental safeguards against the encroachment of man.

Under Watt's legislative proposal, Congress would have only two years to review wilderness proposals from the time it receives them. If it fails to act, the lands would be opened forever for multiple uses, such as mining, grazing and recreation.

Tim Mahoney, Washington representative of the Sierra Club, said Watt is "looking for some way to trade the 'ban oil and gas leasing' issue for some added authority."

Interior spokesman Harmon Kallman cautioned that removing a parcel of land from wilderness study would not necessarily open it to oil and gas leasing.

"It could be put into another classification, such as labeling it a primitive area, or a wildlife refuge," Kallman said, noting that Watt has insisted oil and gas development would only be a last resort.