Admitting that progress in enforcing toxic waste cleanup laws is "not satisfactory," the Environmental Protection Agency yesterday announced a special task force to push polluting companies into cleaning up old dump sites.

Environmentalists were skeptical, concerned that negotiating settlements would not be as effective as legal action and might delay cleanup.

In another enforcement controversy, Rep. Toby Moffett (D-Conn.) charged that EPA Administrator Anne M. Gorsuch had improperly promised a New Mexico refining company that EPA would ignore its air pollution violations. EPA denied any impropriety.

Enforcement chief William A. Sullivan Jr. told a news conference that letters will go out within 90 days to firms known to have contributed chemical wastes to the 115 sites around the country on EPA's top priority cleanup list. The form letter will offer "an opportunity to discuss voluntary cleanup" and will include a "drop-dead date" by which a response is required, Sullivan said.

"We'll give 'em a simple choice: look, do you want to clean it up or do you want us to? If we do it we'll collect the money from you later," Sullivan continued. "We do not intend to engage in protracted negotiations."

Sullivan said he was "not terribly interested" in negotiating cash settlements from the waste generators but would seek their agreement to clean the site to a certain point. There are about 1,500 firms involved in the 115 sites, he said, and "that could be a modest estimate."

Under the Superfund waste dump cleanup program, EPA must try to get the waste generators, haulers and dump owners to fund cleanup if they can be traced. EPA may then spend up to $1.6 billion to do the job, recovering as much as possible from the companies. EPA has so far collected $200 million from chemical companies toward the cleanup effort and has spent $29 million to begin work at 30 sites.

EPA has filed no enforcement lawsuits under Superfund since last June, which Sullivan called "not a satisfactory number." He blamed reorganization of his department in part, and promised an increase in the next six months.

Attorney Tony Roisman, who quit the Justice Department's hazardous waste enforcement division to protest the lack of referrals from EPA, said failure to file suits means a go-ahead for polluters.

In a letter to Gorsuch, Moffett charged her with unethical conduct in a Dec. 11 meeting with executives of Thriftway Co. of Farmington, N.M., who asked permission to exceed EPA's standard for lead per gallon of gasoline. The refinery had been meeting the standard but pleaded that it caused financial hardship, Moffett's letter related.

According to a memo from EPA acting policy chief Joseph Cannon to staff director John Daniel, which Moffett made public, Gorsuch "assured them Thriftway that she would use her prosecutorial discretion not to take any enforcement action against them if they exceeded the standard while we were reconsidering it. They seemed satisfied with this assurance and I think the matter is resolved."