Stadtwerke Köln GmbH is the infrastructure and services company of the City of Cologne. The company undertakes water supply and electrical, gas, heat and steam energy supply through the subsidiary RheinEnergie. Other subsidiaries provide waste management and housing services for the city, in addition to operating the public baths. The subsidiaries Kölner Verkehrs-Betriebe (KVB) and Häfen und Güterverkehr Köln (HGK) operate the city's urban and industrial transportation systems respectively.