Halliburton was sued over groundwater pollution near a now-closed facility on the north side of Duncan, Oklahoma that cleaned missile casings for the Department of Defense. A former Halliburton unit known as the Halliburton Industrial Services Division cleaned solid fuel from missile casings between 1965 and 1991, a process which caused ammonium perchlorate, and possibly nuclear or radioactive waste, to leak into the soil, groundwater, and nearby residential water wells. Residents alleged that they suffered health problems as a result. In October 2015, it was announced that Halliburton settled with about 130 property owners. Settlements involving other property owners were announced in July 2016 and March 2018.