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 toll way (west). The NSSD serves a population of over a quarter million people. Communities served include Waukegan, Gurnee (east of I-94), 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.