The federal government has fined the District of Columbia $50,000 for violating air quality standards at the Benning Road incinerator.

Imposition of the fine, described by a top city official as essentially a token sum, was reported as part of an agreement announced yesterday between the District and federal governments dealing with improving the quality of emissions from the facility's incinerators.

The city said the purpose of the agreement, which is expected to lead to a formal consent decree, is to assure rehabilitation of four incinerators so they will meet clean air standards.

In its announcement, the city said it began a $2.25 million renovation program at the site at 3200 Benning Rd. NE in January before the federal Environmental Protection Agency became involved in the matter.

The EPA told the city in April that emissions exceeded limits the District was required to set in accordance with provisions of the Clean Air Act.

The city said "the purpose of the consent decree is to assure the rehabilitation of four of six incinerators . . . so that emissions from these incinerators will not violate clean air standards."

The city said work would continue through next July. Compliance tests will be conducted next month and in July.

Two of the six incinerators at the Benning site, deemed the worst offenders, have been shut down, the city said. Officials said repairing them was not considered cost effective.

In the announcement that reported the fine, the city said such penalties are imposed routinely even if corrective work is under way. It said additional penalties could be imposed for further violations.

Corporation Counsel Inez Smith Reid said the agreement must be signed by both EPA and Justice Department officials before it is filed in U.S. District Court here. A period for public comment is required before formal approval of the agreement, she said.

Federal officials could not be reached for comment.