Government and community leaders from Boston and nearby South Shore cities argued last night over possible sites for a sewage dump in an open meeting sponsored by the Massachusetts Water Resources Authority (MWRA).

The MWRA must find a place for a sewage treatment plant because of a federal court order that told the state to clear up serious violations of the Clean Water Act, said Paul F. Levy, executive director of MWRA.

In a show of regional loyalties, Quincy residents urged the MWRA to put the dump on Boston Harbor's Spectacle Island, while South Boston residents--who said they lived down-wind from that site--strongly criticized the proposal.

Spectacle is one of 12 locations being considered for a plant that would burn or compost sludge from Boston area sewage. The "island" is actually a mound of trash and dirt formed more than 50 years ago by city garbage dumping.

Proponents of the island site noted that it is uninhabited and farther from residential areas than other proposed locations, such as the General Dynamics Shipyard in Quincy. They also said sewage could be brought to the island through underwater pipes, and would not need to be trucked overland.

"I can't see how you can even consider Spectacle Island," countered South Boston resident Andy Donovan. "I think Quincy should make an effort to clean the harbor up. I smell something real sour in [Quincy politicians'] efforts to push this site."

Representatives from South Boston said that thefoul air from a plant would affect the residentsin their community.

"We have the highest rate of lung disease [inthe city] in South Boston," said South Bostonresident Richard Dayhill. "That's why I'm opposing[the plant]."

Those in favor of using Spectacle Island saidthat situating a plant there could actuallyimprove the state of the man-made island, which isgradually eroding toxic substances into theharbor.

If the island were used as a sludge treatmentsite, it would have to be capped to preventfurther leakage of toxic substances, said QuincyCity Councilor Michael Cheney.

"Spectacle Island is probably leakingsubstances that are presently contaminating theharbor," Cheney said, adding that using the islandwould stop toxic leaks while providing for sludgedisposal.

He added that odor control systems could beadded to the plant to prevent it from having anunpleasant effect on neighboring communities.

Last night's meeting was the fourth in a seriesof open discussions intended to provide a forumfor comment and questions from politicalrepresentatives and residents of the affectedcommunities, Levy said