In one respect, Gladys Simmons, a public housing tenant, is fortunate. She is not one of the estimated 13,000 District residents who are stuck on a list of those waiting to get into one of the city's public housing units. In other respects pertaining to housing, however, she is not to be envied at all.

She and her four children live in the Fort Dupont Dwellings, a huge complex of public housing units, some as much as 45 years old. Located south of East Capitol Street between Ridge Road and Burns Street, it has long been known as one of the most dilapidated projects in the city.

At a time when the rolls of those eligible for public housing show no sign of shrinking, and when the Reagan administration has proposed eliminating federal subsidies for new public housing, the city has asked the federal Department of Housing and Urban Development for permission to demolish the Simmons apartment and 111 others in the 286-unit complex. HUD has not yet responded to the request.

In every section of the city, vacant dwellings succumb to urban decay. Too little has been done by the District government to help get those properties back on the rental market. There are reportedly 5,000 vacant units in the city, although some officials say the number is greater.

This is not a situation in which the District government suddenly looked at the decaying Fort Dupont complex and decided that there were serious difficulties. The problems, ranging from dilapidated units to broken gas lines and water pipes and infrequent heating, have been apparent for years. Severe problems with shifting soil have weakened the foundations of several buildings.

Six months ago, the city began relocating Fort Dupont residents, but some have complained that the units to which they have been moved are in a similar state of disrepair. Gladys Simmons and eight other tenants have filed suit in federal court against the District government and HUD, demanding that they be allowed to stay at Fort Dupont and that their apartments be fixed up. The tenants have also asked for a hearing before the city's Property Management Administration to contest their eviction notices. They are afraid of being left on the streets.

That may be unlikely, but one wonders when the District government will become more responsive to the reality of the city's increasingly serious shortage of safe, decent and affordable housing for the poor. To continue to remove units from the market or to allow them to become vacant is bad policy. At the least, the most structurally sound of the 112 Fort Dupont units ought to be rehabilitated in order to increase the number of decent places for D.C. residents to live.