Camden's Waterfront South neighborhood, located in the southern part of the city between the Delaware River and Interstate 676, is home to two dangerously contaminated areas, Welsbach/General Gas Mantle and Martin Aaron, Inc., the former of which has been emanating low levels of gamma radiation since the early 20th century. Several industrial pollution sites, including the Camden County Sewage Plant, the County Municipal Waste Combustor, the world's largest licorice processing plant, chemical companies, auto shops, and a cement manufacturing facility, are present in the Waterfront South neighborhood, which covers less than one square mile. The neighborhood contains 20% of Camden's contaminated areas and over twice the average number of pollution-emitting facilities per New Jersey ZIP Code.