Septic tank
In the United States, the 2007 American Housing Survey indicated that about 20 percent of all households rely on septic tanks, and that the overwhelming majority of systems are located in rural (50%) and suburban (47%) areas. Indianapolis is one example of a large city where many of the city's neighborhoods still rely on separate septic systems. In Europe, septic systems are generally limited to rural areas.
Lee Tunnel
This long tunnel, of diameter , running from deep at Abbey Mills down to deep at its terminus at Jenkins Lane, East Ham, will capture , or 16 million tonnes, of sewage annually from the single largest polluting CSO in London. This sewage would otherwise flow straight into the River Lea, the Thames Tideway and eventually the Thames Estuary. However, the sewage is now pumped up to the Beckton Sewage Treatment Works – the largest sewage treatment works in Europe – and the resultant clean water emptied into the River Thames. The reason for starting at −75 m is to be ready to collect sewage from the lowest point of the Thames Tideway Tunnel, which is under construction and intended to connect.