The North Shore Sanitary District (NSSD) is the second largest sanitary district in Illinois, encompassing an area from the Wisconsin border (north) to Lake-Cook Road (south) and from Lake Michigan (east) to I-94 Tollway (west). The NSSD serves a population of over a quarter million people. Communities served include Waukegan, Gurnee, Highland Park, Highwood, Lake Forest, Lake Bluff, Bannockburn,  North Chicago, Park City, Zion, Beach Park, Winthrop Harbor, Great Lakes, Fort Sheridan, part of Deerfield, and other unincorporated areas.