NORTH MERRICK - Some Nassau homeowners are blasting a plan to privatize the county's sewer system out of fear that their sewage and water bills will climb. Dozens of concerned residents turned out for a meeting on the proposal this evening at the North Merrick Public Library. County Executive Ed Mangano (R-Nassau) says he's in the early stages of possibly leasing or selling the county's sewage treatment plants. Mangano, who recently privatized the county's bus system, says moves like these are necessary to balance Nassau's budget. Nassau Legislator David Denenberg (D-Merrick) has been a vocal critic of the plan, saying residents will get soaked with high water bills if it happens. "Rates will go up," Denenberg says. "Private monopoly running public necessity always charges a lot more."