People in outside provinces and cities have long envied Hanoians for the clean running water the capital city enjoys. The facts, however, suggest their feelings are misplaced.


A series of water treatment plants have been built in recent years to satisfy the rapidly growing demand in the city. However, the plants, with 100 year-old filtration technology, do not help improve the water quality. Hanoians live in fear that they may one day suffer deadly diseases because of the unsafe water.

Dr. Pham Hung Viet, Director of the Center for Environment Technology Research and Sustainable Development, affirmed that the treated water still has arsenic, manganese and chlorine concentrations well above Vietnamese and World Health Organization (WHO) standards.

Also according to Viet, only the Ngoc Ha Water Plant in Ba Dinh District is churning out water with an arsenic concentration meeting the standard of under 0.01 mg per liter. Meanwhile, water with high arsenic concentrations is still dispensed by other plants, including Phap Van, Nam Du, Yen Phu, Luong Yen and Thanh Tri.

In a sign of just how bad the situation is, research centers often cannot access water treatment plants to take samples for testing – they are barred by uncooperative management. Scientists must rely instead on water samples brought to them by local residents.

Water is treated mostly with sand filtration and chlorination which, according to Viet, is outdated technology. The method eliminates iron and, along with it, a portion of the arsenic.“The method is only helpful in lightly arsenic-contaminated areas (with a ratio of 1 part arsenic to 7 parts iron), while it cannot be used in heavily arsenic-contaminated areas,” said Viet.

But arsenic is not the only threat. Viet said that the detoxification process leaves chlorine residue which, when combined with organic pollutants during transmission to households, creates compounds harmful to people’s health.“These compounds can be very toxic, even with a small volume. They are just like pesticides,” Viet warned.

Dr. Tran Hong Con, a lecturer of the Hanoi University of Natural Sciences, also affirmed that the currently applied water filtration technology in Vietnam is a century old. Only a few of water treatment plants built recently, including Gia Lam and Cao Dinh, have been designed to treat manganese in water.

Con strongly recommends against using chlorine for water detoxification. In developed countries, chlorine has been replaced with ozone or ultraviolet radiation. However, since the technology is too costly, Vietnam still avoids adopting it.