Human groundwater contamination can be related to
waste disposal (private sewage disposal systems, land disposal of solid
waste, municipal wastewater, wastewater impoundments, land spreading of sludge, brine disposal from the petroleum industry, mine
wastes, deep - well disposal of liquid
wastes,
animal feedlot
wastes, radioactive
wastes) or not
directly related to
waste disposal (accidents, certain agricultural activities, mining, highway deicing, acid rain, improper well construction and maintenance, road salt).