GRAVESEND - A Brooklyn community is telling the city to trash its plans to build a waste facility in Gravesend.Gravesend residents say a report shows the area is polluted enough as is. The study claims there are high levels of mercury, zinc and other toxins beneath layers of mud at nine different locations of Gravesend Bay.To move forward with plans for the waste plan, the Department of Sanitation would have to continually dredge Gravesend Bay's waters to make it easier for its boats to ship out waste. The Department of Sanitation says its plan is a good one that has already been approved by the City Council and the State Department of Environmental Conservation.