The District's late-starting year 2000 repair effort has fallen behind the tight schedule set to make sure city services do not fail on Jan. 1, a U.S. General Accounting Office official said yesterday.

The public works, personnel, employment services and procurement departments and the University of the District of Columbia have missed deadlines to make their computers Y2K-compliant, said Ronald L. Hess, assistant director of GAO's Governmentwide and Defense Information Systems Division. Several of these "priority one" departments and other D.C. agencies also are late in preparing manual backup plans that could be used if computer systems fail.

"Services are at risk," Hess said yesterday.

Rep. Thomas M. Davis III (R-Va.), chairman of the House Government Oversight subcommittee on the District, sent a letter Tuesday to Mayor Anthony A. Williams (D) expressing his "serious concern" about the delays.

"While I am cognizant of the enormous challenge undertaken by the current D.C. Y2K team . . . and while I am aware of the substantial progress which has been achieved in the past year under very difficult circumstances, I remain concerned," Davis wrote. "The District has no margin for such schedule slippage."

D.C. Chief Technology Officer Suzanne J. Peck, who received a copy of Davis's letter yesterday, said that the GAO's analysis is largely accurate but that it does not make clear that behind-schedule computer repairs are only a small portion of Y2K preparations that are underway. She said she is confident that the District will finish its work on critical city services by year's end.

"It was always expected we would be running hard to the finish," said Peck, who started the District's Y2K effort in June 1998, years after most other state and local governments began their repairs. "Well, every day is a hard run."

As of yesterday, Peck said, five computer repair efforts that were supposed to be completed at public works, personnel, employment services and UDC were less than 85 percent done. But because these five projects are the only ones among "hundreds" that are lagging, "I am on schedule," she said. Repairs at the city procurement agency are on track, she said.

The Y2K problem stems from the fact that millions of computers and the microchips in many electronic devices were programmed to recognize only the last two digits of a year, assuming that the first two would be 1 and 9.

On Jan. 1, 2000, unadjusted machines will understand the year "00" not as 2000 but as 1900, potentially causing them to shut down or stop working properly. The city, like other government agencies and private sector firms, is rewriting computer codes or replacing systems to ensure that welfare checks, police dispatching, traffic lights, water and sewer service, and hundreds of other operations are not disrupted.

Recognizing its late start on fixing Y2K problems, the District is also undertaking one of the largest contingency planning efforts of any major city. Peck said backup plans have been prepared for 81 of 96 service areas. The deadline for finishing these preliminary plans is tomorrow.

Davis, who will hold an oversight hearing next month on the District's Y2K program, asked Williams in his letter to prepare a report for Congress on steps the city will take to make sure the computer repairs and other Y2K-related work are completed on time. A Williams spokesman said that the delays are "unacceptable" and that Norman Dong, the interim city administrator, has been asked to review the effort.