Sanitary sewers are part of an overall system called a sewage system or sewerage. Sanitation (sewerage and wastewater treatment) is organised differently. The Indus Valley Civilization had advanced sewerage and drainage systems. Local boards were responsible "inter alia" for water supply, drainage, sewerage, paving and cleansing. Waste water and sewerage systems were severely damaged. Thames Water is responsible for all waste water and sewerage provision. There was no sewerage and no system to dispose greywater. Piped water is supplied by Yorkshire Water who also maintain the sewerage system. New infrastructure including modern sewerage, water, and highway facilities were built during this period. Indonesia ranks among the worst countries in Asia in sewerage and sanitation coverage. Such modified PVC is widely used in plumbing for carrying sewerage and other corrosive materials. Water, gas, sewerage, and communications were heavily affected. The city pumps 110 million litres of untreated sewerage to river Ganges. Coatbridge forms part of the Western water and sewerage regions of Scotland. Plastic bags remain a big problem for sewerage system and waterways.