Gelsenwasser AG engages in the water, wastewater, gas supply, and electricity businesses in Germany, the Czech Republic, and Poland. The company operates through five segments: Water, Wastewater, Energy Networks, Energy Sales, and Investments & Projects. The Water segment engages in the purchase, production, sale, and transport and distribution of drinking water. The Wastewater segment engages in the wastewater related business, which include water supply, wastewater disposal, and groundwater management activities. The Energy Networks segment engages in the gas and electricity network activities. The Energy Sales segment engages in the purchase and sale of natural gas, electricity, and heat to household customers, special contract customers, and resellers; and the energy procurement and trading business. The Investments & Projects segment invests primarily in municipal utilities. The company was formerly known as Wasserwerk fÃÂ¼r das nÃÂ¶rdliche westfÃÂ¤lische Kohlenrevier and changed its name to Gelsenwasser AG in 1973. Gelsenwasser AG was founded in 1887 and is headquartered in Gelsenkirchen, Germany. Gelsenwasser AG is a subsidiary of Wasser und Gas Westfalen GmbH & Co. Holding KG.