Screening Screening is the first unit operation used at wastewater treatment plants (WWTPs). Screening removes objects such as rags, paper, plastics, and metals to prevent damage and clogging of downstream equipment, piping, and appurtenances. Some modern wastewater treatment plants use both coarse screens and fine screens. Figure 1 depicts a typical bar screen (a type of coarse screen). Coarse Screens Coarse screens remove large solids, rags, and debris from wastewater, and typically have openings of 6 mm (0.25 in) or larger. Types of coarse screens include mechanically and manually cleaned bar screens, including trash racks. Table 1 describes the various types of coarse screens. Fine Screens
About Long Island. Long Island New York is the largest island adjoining the contiguous United States, extending approximately 118 miles east-northeast from the mouth of the Hudson River. It is separated from the mainland on the north by the Long Island Sound and bounded by the Atlantic Ocean on the south and east.
Long Island Sound, an estuary 110 miles long and up to 21 miles wide, separates Connecticut to the north and New York's Long Island to the south. Nearly 3 million people live in Nassau and Suffolk counties; adding the population of Kings and Queens counties brings the total to 8 million.