The 13.5-kilometre-long To Lich River runs through the districts of Dong Da, Thanh Xuan, Cau Giay, Hoang Mai, and Thanh Tri.
The river receives around 150,000 cubic metres of untreated domestic and industrial wastewater directly discharged from 300 drainage pipes daily.
The river is battling a massive amount of wastewater and waste from households, production facilities and craft villages along its banks.
A drainage pipe from a residential area in Ha Dong District flows into the Nhue River.
The 10-kilometre-long Kim Nguu River is also contaminated. The riverbed is constantly filled with various types of waste.
The Set River flowing through the Hai Ba Trung and Hoang Mai districts constantly emits a foul odour.
Each day, 55,000 cubic metres of untreated wastewater are discharged into this river.
A lot of waste is released into the river daily from a temporary market on Phan Dinh Giot Street.
An environmental worker who specialises in collecting rubbish on the Set River in Hoang Mai District said most of the waste collected is plastic, non-biodegradable household waste, and pieces of wood. He starts working at 7 am, and the boat is usually packed with waste within two hours.