D.C. Mayor Marion Barry yesterday rejected a federal proposal to house hundreds of the city's homeless persons in trailers placed on District property, and he suggested instead that U.S. officials put the temporary structures on such federal sites as the National Arboretum and the U.S. Naval Observatory.

In a letter to Margaret M. Heckler, secretary of the U.S. Department of Health and Human Services, Barry criticized the federal plan as impractical and inadequate. He said it failed to satisfy a U.S. District Court judge's ruling last month requiring "appropriate plans" to eliminate homelessness in the nation's capital.

"We are not prepared to take sorely needed local dollars to pay for either short-term or long-term solutions that are solely the responsibility of the federal government," Barry said in a reference to housing the estimated 600 residents of a dilapidated shelter run by the Community for Creative Non-Violence at 425 Second St. NW.

Dixon Arnett, the HHS deputy undersecretary charged with finding housing for the shelter residents, said he was disappointed by the lack of cooperation from District officials and asserted that Barry's response "sort of drips with sarcasm."

Arnett ruled out placing trailers on the seven federal sites recommended by Barry, which include Walter Reed Army Medical Center, the U.S. Soldiers and Airmen's Home, Fort McNair, the Washington Navy Yard and Bolling Air Force Base.

"We will move ahead to bring into being other plans without the mayor," Arnett said. "What we will end up doing is proving to the mayor and the media and the courts and everybody else that this can be done for the kind of budget we have worked out."

Last fall, President Reagan announced his intention to create a "model shelter" for the District's homeless, ending a 51-day fast by CCNV leader Mitch Snyder. The current dispute arose in June when CCNV, claiming the planned $2.7 million federal renovation was inadequate, blocked federal workers from starting work. The federal government subsequently announced plans to close the shelter, and Snyder filed suit in U.S. District Court to force a larger federal commitment to the renovation.

District Judge Charles R. Richey on Aug. 19 ruled against CCNV but said the federal government must provide alternative shelter before it can close the building on Second Street. Next Thursday, the U.S. Court of Appeals is scheduled to hear appeals of the ruling by Snyder's group as well as by the federal government, which claims it should not be required to provide alternative shelter.

Snyder said yesterday he was not surprised that the mayor rejected the trailer plan proposed by HHS and the D.C. Coalition for the Homeless, a group that would have operated 40 temporary facilities placed around the District.

"I think the mayor would have been a fool to accept the invitation that was offered to him, which was to take responsibility for all of the people in the Second Street shelter and to bear the financial burden for that when everybody knows that $2.7 million will not go very far," Snyder said. "The mayor doesn't want to get stuck with a lot of homeless people in trailers with the federal government wiping its hands, walking away and saying, 'It's all yours, Marion.' "

Barry said that a District attempt in 1984 to use trailers proved to be "inadequate" and that the cost and staffing requirements were prohibitive. He noted that the federal plan failed to address the lack of water and sewer services at the sites. In addition, the mayor argued that several of the short- and long-term sites "are occupied or otherwise unavailable."

Arnett countered yesterday that the District's previous experiment with several trailer shelters in Georgetown had been effective. Arnett cited a report prepared under the mayor's letterhead in March 1984 that concluded that the experiment was "an overwhelming success."

Snyder said his group is "confident the court will find in our favor. Assuming the court were to find totally against us, the government would be free to shut the shelter down and throw everybody out in the street."