The howls of protest from Gravesend fell on Mr. McMahon's deaf ears as he pushed forward with the Gravesend dump regardless of the strong sentiment of those whom he now seeks to represent in Congress and the obvious problems with the site," Harrison said at the site yesterday.

McMahon (D-North Shore) said Harrison was "relentlessly mud-slinging because he has no record of his own to run on, nothing of substance to add to the discussion, and no vision for addressing the needs of Staten Island or Brooklyn."

The two will face off in a Democratic congressional primary on Sept. 9.

According to Harrison, the Gravesend transfer station is the only site in the city's waste management plan that will have to be dredged to accommodate new, larger transfer barges.

That dredging, he said, will disturb the bay bottom, where spoils from an old incinerator that was on the site "lay in wait to pollute our bay, upset our ecosystem, make the fish unsafe to eat and potentially foul the beaches of Staten Island."

He also said the law requires the area to be laced with rat poison, which, together with the effluent from the garbage, will run off into the water, where it may affect fish, birds and recreational use of the area.

"The facts here are simple and undeniable," Harrison said. "After 30 years of illegal toxic assault, Gravesend has the right to expect that the incinerator will not again be opened under a different toxic guise. Gravesend has the right to expect environmental justice."

McMahon countered that the city's waste plan had to move forward even though some of the transfer-station sites "weren't perfect."

"Siting decisions became incredibly difficult," he said.

McMahon added that he "continues to work with local leaders to explore alternative locations to the Southwest Brooklyn transfer site."