RARE IN OUR news business is the good local story that keeps on being 100 percent good for 20 years -- and still is far from over. As the countless friends and families of For Love of Children -- a singularly important organization in Greater Washington -- can attest with enthusiasm, the quality of life here has been improved markedly through the devotion, determination and creativity of caring volunteers. That is the success story of FLOC, a not-for-profit organization that has been serving neglected, homeless children and families with practical programs, effective advocacy and proven results. It's well worth celebrating -- which is precisely what FLOC's impressive volunteers and staff professionals invite you to do today from 11 a.m. to 3 p.m.

To appreciate fully what the FLOC "Family Fair" will be celebrating on the Van Ness campus of the University of the District of Columbia, consider what this city did with -- and to -- homeless children some two decades ago. Hundreds of them were kept in grim barracks at a place called Junior Village. By early 1965, there were more than 900 children stashed there, living in perpetual fear of being abandoned, separated from their siblings or shunted from one cruel, inadequate temporary arrangement to another. In that same year, several members of Washington's clergy, fresh from the civil rights movement, sought next to end what had been an exclusion of institutionalized city children from the special sense of belonging that comes with a family setting.

They formed FLOC; they lobbied; they found and readied foster homes with loving parents; and, with other support groups over the years, they managed to close down Junior Village. Last year, FLOC's foster-home program served 128 children. Forty-three new children were placed and 44 left; 15 were returned to their natural families or relatives; eight were placed for adoption (five with foster parents); 10 were transferred to other agency foster homes; and five were shifted to residential treatment for severe emotional programs or education for the multiply handicapped.

FLOC also runs an advocacy center, conducting lobbying and litigation for enlightened and effective public welfare policy. The accent lately has been on homeless families that have had to move in and out of emergency shelters in city-leased hotel space as their children were placed in foster care. Among the operation's objectives: to prevent separation of children and parents, and to establish families in permanent housing.

Tied to this is yet another FLOC operation called "Hope and a Home," aimed at helping about 30 families at a time to find both of these things as swiftly as possible. Included are parent support groups, jobs for some of the teen-agers who help experienced craftsmen on painting, carpentry and other projects, special counseling and assistance on home cost-management. A FLOC subsidiary, MANNA, buys, renovates and leases houses and apartments for low-and moderate-income families.

There is also a learning center, which supplements the D.C. public schools' special education programs. It is now concentrating on teen-agers and seeking volunteers for one-on-one relationships with the center's graduates. Coming up are new efforts to prepare teen-age mothers for self-sufficiency.

In many ways, the people who have worked with FLOC have surprised themselves with the results they have been able to achieve. But they have not been content merely to do things the same way every year, or to become a bureaucracy like those they have fought to abolish or sharpen. Mostly, they live up to the name of the organization -- and given the enormity and complexity of their mission, that is a precious quality.