Chennai's Mahindra World City practices waste segregation in every residential project and has installed red, blue and green dustbins to ease segregation of waste at source. The city has a biogas plant inside its premises and the collected food and kitchen waste is sent there for conversion to biogas. The city also has a solid waste management plant where the green waste is sent for conversion to compost. The paper waste collected by recyclers is recycled for usage and a sewage treatment plant of 2 million litres allows the residents to treat waste water and reuse it for washing toilets and cars.