There are a total of 19 drains in Delhi. Of these, three discharge into the Agra canal, one into downstream Yamuna and 14 into the Delhi segment of the river. Nearly 2,800 million litres daily (MLD) of sewage/industrial effluents containing 200 tonnes (t) of BOD and 160 t of suspended solids enter the river every day through the 11 drains which are monitored. The Najafgarh nullah contributes around 60 per cent of the discharge and about 40 per cent of BOD load in the Yamuna. The Shahadara nullah is responsible for another 20 per cent flow and 24 per cent BOD load.