Valerie Riefenstahl of Annandale, who sells troubled savings and loans for the Federal Home Loan Bank Board, takes the elevator down to the building's child care center every day so she can nurse her 4-month-old son Austin.

Mary Conklin and her husband Jim Callow routinely visit the Senate Employees' Child Care Center to share lunch with their 4-year-old daughter Andrea.

During their 40-minute commute to the Department of Labor, Rick Glaser chats about the day's events with his son Matthew, 2 1/2, before dropping him off at the agency's on-site child care center.

Up to now, the development of child care centers at federal agencies has been piecemeal and erratic, generally a result of parents' organizing and defying bureaucratic tangles to get the centers open. But the General Services Administration, prompted recently by a congressional subcommittee, says child care is going to be one of its top priorities this fall in improving the working environment for federal workers.

"An integral component of the {GSA's} quality work place program is the provision of day care centers where the need exists," GSA Administrator Terence C. Golden said in congressional testimony this year, referring to a program to improve the federal work environment.

Saying that he felt there was a need for federal agencies to enhance their attractiveness as employers, Golden added, "We have more satisfied employes {when} the children are close at hand, and as a result, I think we are more productive."

Currently, there are more than a dozen on-site child care centers at federal facilities in the Washington area, including three opening this month. Several more are planned in other parts of the country in the next two years.

As part of the government's effort, the GSA has promised to survey federal workers across the country on their child care needs, and is writing a booklet for agencies to follow when developing a center. GSA also has pledged to find the necessary space in either existing or new quarters for centers in agencies that want them.

At a time when more parents are struggling to juggle work and home life, the families that use the on-site centers say that having child care where they work has made a big difference in their relationships with their children and their attitude at their jobs.

"I came back {after two months of maternity leave} because Austin could come with me," said Riefenstahl. "Having breast-fed my first child, it's such a special time. It keeps my stress level down."

Considering the size of the federal work force, about 355,000 employes in the Washington area alone, the number of on-site facilities is still modest, with fewer than a thousand child care slots available. The shortage is complicated by the fact that the centers also take children of parents who do not work for the government.

Centers give priority to agency employes, but most start out accepting children of other federal agencies and the general public in order to get the center off the ground. After a short time, however, most have found they wind up with long waiting lists.

Federally sponsored centers are operated here by the departments of Housing and Urban Development, Education, Health and Human Services, Labor, Transportation, as well as the Senate, the Bank Board, the Agriculture Research Station in Beltsville, the Goddard Space Flight Center, National Institutes of Health, the Defense Mapping Agency in Bethesda and the National Bureau of Standards, according to GSA and the Labor Department.

A center organized by parents at the U.S. Patent and Trademark Office and other workers in Crystal City opened in Arlington this year across Rte. 1 from the federal offices.

In addition, three centers are opening this month: at the Environmental Protection Agency, the House of Representatives and GSA. The GSA facility will be operated jointly for that agency, the Office of Personnel Management and the Department of the Interior.

Not all of the plans for growth have panned out. Golden said in his congressional testimony in May that about two dozen more centers would be added at federal facilities in different parts of the country by the end of fiscal 1988. Since then, nine of those on his list have been dropped for "lack of interest," according to GSA. Four were to be in the Washington area, at the Pentagon, the Internal Revenue Service, the General Accounting Office and the Government Printing Office.

An IRS official said that agency's center was merely postponed, and that four pilot centers are being launched in offices in other parts of the country.

The Social Security Administration rejected on-site centers, choosing instead to establish a child care information and referral service. James Kissko, representing the Social Security Administration, told the House subcommittee that his agency believes parents prefer child care near their homes rather than at work, particularly because they do not want to subject their children to a commute.

Rep. Cardiss Collins (D-Ill.), chairman of the House subcommittee on government activities and transportation, took GSA to task at hearings in May for being slow in promoting on-site centers and in helping to get them established, but she said last month that the agency appears to be doing better.

"When we started looking at it, it was because we started getting letters" from employes in need of child care, she said. "Managers were resistant."

Each center operates independently, determining its own fees and age groups. Until this month, the Bank Board center was the only federally sponsored one in this area caring for infants, the age at which the shortage of child care is greatest. The centers opening at the House and GSA also will take infants.

Fees range from $50 a week at the Department of Education to $105 to $130 a week at the new House center, according to a government compilation of rates. The high rates at some of the on-site centers have concerned some federal employes, who say this will mean only top-grade levels of employes will get the benefit of the centers.

Jessie Marshall, head of the board of the new Crystal City Working Parents child care center, told the House subcommittee that average family income at that center is $72,000 and the average grade level GS 13.

"If GSA is going to get involved, their involvement should also be at a level that makes it not only able to exist but able to exist for all levels of federal workers," Marshall said. Of 500 parents originally saying they were interested in child care at the center, 300 eventually said the fees -- ranging from $81 to $115 a week -- made it too expensive for them to use.

Some centers, including the one in the House, are planning scholarship programs to help lower-income workers.

For working parents with busy schedules, time is the factor mentioned again and again.

"I was determined that I was not going to go 10 or 11 hours a day without seeing my child," said Mary Conklin, in charge of mail operations for Sen. Donald W. Riegle Jr. (D-Mich.), who helped instigate the center when she had her first daughter four years ago.

"Whatever happens, you can be there in no time flat. We can have a birthday party for her there," Conklin said, adding that "it makes you think long and hard about quitting jobs."