In August 1972 the area affected by the contaminated
ground water covered about 4 acres (1.6 hectares) and extended nearly 1,000 feet (330 meters) downgradient from the disposal site. By late January 1973 the plume had migrated laterally to affect an area of about 15 acres ( 6 hectares) while extending over 1,500 feet ( 460 meters) downgradient. The lateral migration is attributed to a seasonal change in the local flow system. At least eleven existing domestic water-supply wells have been rendered nonpotable by this pollution.