In a bleak basement corridor on the Van Ness campus of the University of the District of Columbia, Claude Ford was beaming. The classrooms and lounges upstairs were full of evening students absorbed in their studies, but Ford was not concerned about academic progress. He was into janitors.

Ford, UDC's vice president for administration, was watching happily as teams of men and women toting buckets and mops and bathroom supplies fanned out to attack the grime. They looked like any other janitors, but to Ford there was an important difference in this bucket brigade: As employees of a private contractor instead of the city, they came cheap and apparently worked hard under the eagle eye of an on-site supervisor responsible to a demanding boss.

Sent in by a downtown firm under an $800,000 contract, they were in their first week on the job, replacing nearly 100 city workers who in Ford's judgment cost more and performed less. The city workers, laid off by the Department of General Services when the university switched to a private contractor, were left to protest and picket at the District Building in frustration while outsiders -- part-timers, short-timers, transients -- supplanted them.

The replacement of public employes by private contractors has been happening more and more, in bits and pieces, as city government adminstrators attempt to keep services coming in a time of fiscal constraint. The practice of "contracting out" was a nationwide fad of municipal management a few years ago, before the District of Columbia struck it poor. Now it is increasingly being adopted here by officials like Ford, who see it as a way to get more for their dwindling dollars.

Public employe labor unions, especially the American Federation of State, County and Municipal Employees, which represents half the 31,000 city workers here, have bitterly opposed "contracting out." They argue that it encourages low wages, disguises the real numbers of people paid out of tax dollars, dilutes responsibility for service to the public and invites corruption. But Ford was not thinking of that issue as he watched the trash collectors and window washers go to work.

"You know, we had a meeting today and it seemed like the first time that conference room had been vacuumed up in six months," Ford said. "You could hear the stuff being sucked up through the hoses."

That brought a grin from James Reese, site supervisor for the contractor, United Services Inc. Reese was standing in the corridor handing out assignments to the cleaning crews. He turned down a reporter's request to ask some of the workers to stop and talk. "This is the first week of our contract, and you can see what the conditions are," he said. "I don't want to see the workers doing what was going on before, standing around chewing the fat. UDC would be mild with me compared to how I would be with them."

According to Ford, if the university had continued to contract with the city's Department of General Services for mainttenance and custodial work, as it did in the past, it would have cost $2.7 million this fiscal year. But putting the janitorial work out to private contract, he said, the total bill was held to $1.56 million. UDC, he said, gets "more bang for the buck."

United Services, a 10-year-old black owned janitorial services company, also has the cleaning contract for the new D.C Superior Court building; before that was awarded, city court buildings were cleaned by District of Columbia government employes assigned by General Services.

Carroll Harvey, acting director of General Services, acknowledges it is cheaper for building administrators to hire private contractors than to use city cleaning crews. "The contractor has modern equipment," he said. If we haven't been investing overtime in equipment, we can't expect our employes to be as productive. The question is, what will it take to bring our own forces up to an outside contrator's standards? We have people who came aboard 20 years ago who haven't been retrained. It's not their fault."

Because department heads are generally at liberty to make their own decisions on this issue, there is no overall list of contracts that have been awarded in which city employes have been replaced by private-sector workers. But there is a growing number, including:

Operation of the dog pound. Formerly done by workers from the Department of Human Services, it is now done by the Washington Humane Society under a $283,500 contract.

Processing of real estate tax payments. Once a five-month chore at the Department of Finance and Revenue, it is done by Riggs National Bank. Riggs counts the money, records the payments and compiles a record for the city, in exchange for being allowed to keep the cash and invest it to earn interest for 48 hours, according to D.C. Auditor Matthew Watson.

Payment of youths in the summer jobs program. Always an administrative nightmare, this task was contracted out last summer. It still was an administrtive nightmare, but as city officials happily noted, it was someone else's nightmare, not theirs.

Staffing of nursing positions in city institutions. According to Paul Levine, long-term care administrator in the city's Department of Human Services, this is done not to save money but to cope with the acute shortage of the nurses in the metropolitan area. Contractors, he said, can provide nurses who want to work only part-time or on limited schedules -- like office temporaries.

Water quality analysis at the Blue Plains sewage treatment plant. City administrator Elijah B. Rogers said the federal government was holding up grant funds "because of the unsatisfactory quality of the work, so we let it out on contract and got the funds released. We also did it on ambulance billing for the rescue squads."

Rogers said in an interview that "the contracting policy is not ad hoc. We have been looking at this. Given our dwindling resources, contracting out is one option. We don't do it just to reduce the work force. We say, if you can do it more cheaply and effectively in-house, fine. Management has to be flexible."

There are several reasons why private contractors can often perform the same service more cheaply or more efficiently than city employes, officials in several departments said. They pay lower wages and lower pension benefits, they have specialized machinery, they are not bound by the city's residence requirement in hiring personnel, they can fire unproductive workers and they have special expertise in their particular fields.

That does not always means that a private contractor can provide better service than city workers. Public housing administrator Sidney Glee, for example, said he recently dropped a contract for boiler maintenance and gave the assignment to workers in his own department. Not only did he save about $250,000 a year, he said, but "we are getting better service. If these boilers go out on a night or on a weekend, maybe we can't reach the contractor or maybe his people are afraid to go to some of these places at night. Our people are available."

That seemed to buttress the argument of critics that contracting out blurs the lines of responsibility for delivering services to the public. But it is clear, according to Harvey, Rogers and other officials, that the need for the city to trim its payroll and limit the pension obligations, as well as the cost of equipment, training and special expertise, is going to require administrators to turn more and more tasks over to outside contractors. Among those likely to go are printing, security services at city buildings, maintenance of the city's vehicle fleet, the processing of water bills and the operation of computers.

In 1977, AFSCME, the biggest public workers' union, commissioned a book entitled "Government for Sale: Contracting Out, The New Patronage." The author, John Hanrahan, concluded that "contracting out, far from being a potential financial boon for state and local governments, is a major source of government corruption, financial waste and inefficiency." Furthermore, Hanrahan said in an interview, it fosters the illusion that reduction in the number of city workers actually means a reduction in the budget, when all it really does is give city jobs to others. (The city's payroll has dwindled by several thousand workers over the last five years to its current level of about 31,000, but there is no way to tell how much of that is attributable to contracting policies because there is no central repository of information about the contracts).

Rogers, the city administrator, and Watson, the D.C. auditor, said the city's experience generally has been positive in financial terms, whatever its impact on the workers. As for the potential corruption, Rogers said, nobody had ever raised that issue to him. "Corruption is not a factor here," he said. "The District is relatively clean."