Waste water from industrial sites amounts to one third of total waste water discharged into To Lich river, and may have serious effects on the river water quality. With the total amount waste water of factories (Hanoi beer alcohol and beverage joint stock corporation (HABECO), Trang An JSC and Thuong Dinh industrial park) of 45,000 m3/day, these factories accounts for more than a half of total industrial waste water released into To Lich river. The analytic results of water samples taken from To Lich river show that the parameters of DO, COD, BOD5, TSS, NH4+, NO2- and coliform.
