Rita M. Lavelle, director of the Environmental Protection Agency's hazardous waste program, has hired a private lawyer to defend her "personal interests" in any lawsuits stemming from her administration of the nation's toxic waste laws.

In a statement issued yesterday through an EPA spokesman, Lavelle said she has hired James J. Bierbower, former president of the District of Columbia Bar and a leading criminal defense lawyer who represented former Nixon administration official Jeb Stuart Magruder during the Watergate trials.

Lavelle said she would be "personally responsible" for Bierbower's fee, and he would serve as her "personal counsel in any litigation which might arise as a result of my administration of the Superfund and Resource Conservation and Recovery Act."

Lavelle has been under fire from environmentalists and a House subcommittee for her handling of the Superfund and resource conservation act, which govern the cleanup of toxic waste dumps and the safe disposal of hazardous materials.

"While I also call upon the services of the EPA general counsel, his first concern must naturally be the welfare of the agency," Lavelle said. "Mr. Bierbower's first concern will be the welfare of Rita Lavelle."

Neither Lavelle nor Bierbower gave any indication yesterday of what, if any, litigation he would handle, but it appears likely that his first task will be to defend Lavelle against the charges of an agency whistle blower who has accused her of trying to get him fired.

The EPA has requested an administrative law hearing on the charge, saying it disagrees with the Labor Department's finding that Hugh Kaufman, an employe in Lavelle's division, was harassed in an effort to silence his frequent criticisms of agency policy. The hearing, postponed once at Kaufman's request, is set for Feb. 14.

Lavelle also could face charges stemming from her congressional testimony in the Kaufman case. Lavelle denied under oath to a House Science and Technology subcommittee that she had ordered an investigation of Kaufman or said she would like to fire him.

The subcommittee later obtained evidence that she had done both, and subcommittee Chairman James H. Scheuer (D-N.Y.) said he was "leaning heavily" toward asking the Justice Department to prosecute Lavelle on charges of perjury.

Staff aides said yesterday that Scheuer still is considering that option.

Earlier this month, the EPA abruptly canceled its plans to hire private lawyers to defend Administrator Anne M. Gorsuch against a contempt-of-Congress charge, although the Justice Department had assigned a team of lawyers to the case.