Rita M. Lavelle pleaded not guilty yesterday to a charge of contempt of Congress for refusing to testify before a House subcommittee investigating her management of the Environmental Protection Agency's hazardous-waste cleanup fund.

U.S. District Court Judge June L. Green accepted Lavelle's plea, released her on her own recognizance and scheduled a hearing for June 22 to set a trial date.

The House subcommittee wants to question the former assistant administrator of the EPA about allegations of conflict of interest, mismanagement and political favoritism at the agency.

After the 10-minute arraignment, Lavelle's lawyer, James J. Bierbower, told the press, "She has testified 12 times before Congress. I suspect she will testify before Congress again. She will probably be subpoenaed again no matter what happens here."

Asked why Lavelle does not testify now, the attorney said, "Who wants her to testify? She's here. Where's the person who wants her?" Referring to Rep. John D. Dingell (D-Mich.), chairman of the House Energy and Commerce Committee, which has asked for Lavelle's testimony, Bierbower said, "Get Mr. Dingell to call me. I'll go in the courtroom and wait for somebody who wants her."

Bierbower then entered an empty courtroom on the second floor of U.S. District Court and waited with Lavelle and his son and partner, Mark B. Bierbower. "I'll be here for five minutes," the elder Bierbower announced. "Nobody showed," he said at the end of five minutes. "I take that as a concession."

Lavelle, sitting near Bierbower, declined to comment.

If convicted, Lavelle, 36 and unemployed, faces up to a year in jail or a fine of up to $1,000 or both.