The latest bid by the Washington Suburban Sanitary Commission to expand its cramped Hyattsville administrative headquarters has drawn strong opposition from local residents.

More than 150 Hyattsville citizens filled the City Council chambers last week to protest WSSC plans to construct a two-story, 60,000-square-foot annex on the commission-owned parking lot adjacent to the building on Hamilton Street.

The council promised to vote on the proposal by Monday. The Hyattsville council can make recommendations, but the final decision on the proposed expansion will be made by the councils of Prince George's and Montgomery counties.

WSSC general manager Robert S. McGarry said, however, that the agency will abide by Hyattsville's decision.

"We didn't argue last time they turned us down and we won't this time," he said.

Citizens blasted the Hyattsville council for bringing up the expansion proposal only a year after the defeat of a similar plan.

"We're perplexed and saddened that the issue is up again," said James D. Riley, president of Concerned Citizens of Hyattsville. "We thought we had killed the issue forever last time."

Citizens, fearing increased traffic on narrow residential streets, last year defeated a proposal to construct a five-story addition on top of the commission building. More than 1,100 Hyattsville residents signed petitions opposing that plan.

"This is an area of one-family homes. WSSC is like a spreading cancer," said John P. Lautz, who lives on 37th Avenue.

Residents said they fear traffic will endanger children using the adjacent Magruder Park. They also oppose the expansion because the bicounty agency pays no city taxes.

Not all citizens opposed the plan. Supporters, who appeared to be about a quarter of the residents attending the meeting, called the WSSC a "good neighbor" and said they want the commission to stay in Hyattsville.

"We're going to end up chasing the WSSC away," said Frederick S. Pearce of 39th Avenue. "They are the only major thing we have in the city. Shame on you people."

The WSSC has been trying to expand its four-story building since 1969, when officials first proposed the vertical extension. Commission officials have studied and rejected the construction of a new structure on Rte. 1 in downtown Hyattsville and recently have discussed the possibility of relocating out of the city and perhaps out of Prince George's County.

Limited space in the present Hyattsville building has forced the WSSC to rent 13,000 square feet of office space in the Presidential building in Prince George's Plaza and 56,000 square feet in the Arbitron Building in Laurel, at a cost of $578,000 a year for both leases.

WSSC assistant general manager John M. Brusnighan said, "The name of the game is keeping the rates down. It will be cheaper to build a new building than to lease office space, and if it's not here in Hyattsville, then we'll go somewhere else."

Last week's meeting drew caustic remarks from residents who said the City Council has talked to the WSSC "behind closed doors" in attempting to stike a bargain with the agency at the residents' expense.

"Statements by some City Council members reek of demagoguery and emotional blackmail," said Mickey Schiesser of Gallatin Road, who ran unsuccessfully for a council post in last May's elections.

Schiesser said she was referring to statements allegedly made by some City Council members -- that if WSSC left the city a correctional institution or drug rehabilitation center might take its place. Council members denied they made such statements.

The proposal that was the subject of last week's public hearing came during an Oct. 30 meeting between City Council members and WSSC officials. Mayor Thomas L. Bass said he called the October session to verify WSSC plans and to explore the possibility of a compromise that would keep the commission in the city.

"We don't do anything behind closed doors," he said. "We operate under the sunshine laws."

Other council members were indignant at the accusations made during the hearing.

"It's irresponsible . . . to level these kinds of charges," said Robert E. Trumbule, council member from Ward Two. "We had heard through the grapevine that WSSC was planning to leave the city and wanted to meet with them to talk about it."