The Environmental Protection Agency, trying again to avoid creating new hazardous-waste dumps in cleaning up old ones, told its regional offices yesterday to burn, store or treat waste from dumps whenever possible instead of putting it in landfills.

A new policy statement for the agency's "Superfund" abandoned dump cleanup program also tightened the rules on when landfills could be used.

"We expect short-term dislocations," said Gene Locero, enforcement chief in the hazardous-waste program.

Locero said about half the 58 federally licensed commercial landfills might be barred from accepting waste transferred from Superfund cleanup sites, though they might still be permitted to handle the waste in another way, such as incineration.

The agency will extend to all Superfund cleanup efforts its policy of not using landfills that have serious outstanding violations of the federal hazardous-waste disposal law "or other conditions that would affect environmentally sound operation." Up to now, only long-term cleanup efforts have had to avoid landfills with violations.

Several studies have suggested that the EPA might be creating new Superfund dump sites by using landfills to dispose of the waste it is cleaning out of abandoned hazardous-waste dumps. The new policy statement was the third since September to address the problem.

The agency has used landfills in pursuing the congressional mandate to select the most "cost-effective" cleanup for each site. But William N. Hedeman, head of Superfund, said the agency was having second thoughts.

"At almost every site, incineration costs more in basic dollars today" than putting a clay cap over the dump, Hedeman said. But when costs of monitoring a landfill, perhaps for 50 years, and the possible costs of cleaning up ground-water contamination are considered, "at most sites incineration is more cost-effective in the long run," he added.

The agency will permit exceptions. For instance, it will let a landfill with outstanding violations be used for Superfund waste as long as it is under a signed consent order or court decree to correct them on a fixed schedule and as long as the waste goes to part of the landfill that is not contributing to whatever environmental problems there are.