Dwr Cymru Welsh Water

Welsh Water provides water supply and sewerage services to over three million people in Wales and some adjoining areas of England.

The company operates 81 reservoirs, 105 water treatment works and supplies an average 900 million litres of water every day through a network comprising 27,000km of water mains, 532 pumping stations and 715 service reservoirs. DCWW also collects wastewater (including surface water and highway drainage) through a network of 19,000km of sewers, 1,700 sewage pumping stations and 3,300 combined sewer overflows. Wastewater  is treated at 832 treatment works.