The District's utility regulating commission has let a year pass without making required monthly audits of Pepco's fuel adjustment clause to ensure that this $100-million-a-year automatic pass-through of costs to customers is not abused by the electric company.

The disclosure was made by D.C. People's Counsel Brian Lederer yesterday after he and other city officials learned of the situation through the persistent inquiries of an angry citizen - District resident Shirley Furbush, who began making phone calls to Pepco and city agencies after becoming infuriated when she saw that the fuel adjustment portion of her $14 Pepco monthly electric bill came to $5.20.

Lederer, the city official who represents consumers in utility cases, said yesterday that he has begun a formal investigation of the fuel adjustment clause and the Public Service Commission's failure to make a monthly audit.

The failure "may mean that Pepco's getting away with murder," said Lederer. "It may mean the Pepco is able to run [a substantial portion of] its business on an unregulated basis."

Elizabeth Hayes Patterson, the commission chairman, said yesterday she had thought the audits were being performed until she received a phone call from Furbush and checked it.

"I learned I was mistaken and an audit had not been done since 1977," said Patterson. ". . . In fact, we have been very busy. We do not have a huge staff."

One reason the commission and its staff have been busy: their continuing work to make a decision about Pepco's request for a $45 million, 16 percent rate increase for its 186,000 D.C. customers.

Lederer said commission staff member testified in the rate case hearings earlier this year that they audited Pepco's fuel adjustment information monthly, but Patterson said the testimony was not clear on the point.

Pepco is required to submit this information monthly for the commission's approval, Patterson said the commission has been granting approval routinely on a "provisional basis" with the staff's recommendation.

She said the staff apparently felt it could recommend approval without auditing the information since "provisional" approval was always subject to revision later. Neither she nor the other two commissioners realized that the monthly staff recommendations were not based on actual audits, they said.

By putting off the audits, Patterson said, the staff was able to concentrate on what was apparently considered more pressing business.

By putting off the audits, Patterson said, the staff was able to concentrate on what was apparently considere more pressing business.

She said that after learning of situation last Wednesday she ordered the staff to bring the monthly audits up to date by hiring outside professional help.

Pepco gets 34 per cent of its District revenue from fuel adjustment charges to customers - an automatic pass-through of its costs for coal and oil that fluctuates monthly.