Green Technology » Sciences - Technology

May 25, 2019, 7:55 pm

Tap water in Hanoi filtered with 100-year-old technology

(12:52:39 PM 15/06/2015)
( - Most of the water supply plants in Hanoi which exploit underground water use outdated filtration technology which cannot eliminate toxic substances.

 Tap water in Hanoi filtered with 100-year-old technology

Dr. Cao The Ha from the Hanoi University of Natural Sciences said the treated water samples had not been found containing concentrations of arsenic, manganese and chloride higher than Vietnam and WHO (World Health Organization) standards.

Ha said very few of the operating water plants in Hanoi use technologies that permit the standard arsenic residue at below 0.01 mg per liter. 

Many plants provide water with a high arsenic concentration, including Phap Van, Luong Yen, Thanh Tri, Van Phuc and plants in the former Ha Tay province.

To eliminate solids, such as manganese, calcium, magnesium and barium, the plant uses old techniques, including spraying systems and chlorination.

The methods, according to Ha, aim to eliminate iron which helps get rid of arsenic. However, they can work only in areas with a mild arsenic content at a 1/7 ratio (one arsenic, seven iron). 

A survey conducted in 2006 by water experts in eight provinces in the Red River Delta found that though underground water went through sand filtering tanks, the water taken from 20 percent of surveyed water wells in Hanoi contained arsenic.

Hung, a resident in Ha Dong district, said the technologies had been used for a century.

“Water plants said that they provide ‘clean water’. However, we often find dregs in tap water with our naked eye, and the bleach odor is very strong,” he said.

The Ministry of Health, which analyzed water samples taken from 16 water plants and seven water supply stations, found that the water did not meet five criteria.

The water samples from 20 water supply centers had a chloride residue higher than the permitted level – 0.3-0.5 mg per liter.

According to the Ministry of Health, if the chloride residue is below 0.3 mg per liter, water users may get diarrhea and other digestive diseases. 

Meanwhile, if the residue is higher than 0.5 mg per liter, toxic organochlorine substances will be created, harming people’s health.

Hoang Van Thang, head of the planning division of a water supply company in Ha Dong district, admitted that the company’s filtration technology had been used for many years.

In early April, the pipeline that brings water from the Da River to Hanoi reportedly broke for the fifth time since it was put into operation in 2012. As a result, Hanoians in some areas had to use muddy water for several days until the problems were fixed.

Many Hanoians said they do not believe the “clean” water provided by the Hanoi Water Supply Company is clean enough.



Send comments you read about: Tap water in Hanoi filtered with 100-year-old technology

* *
(Environmental News welcomes your opinions read the article. The discussion will be reviewed before posting. Environmental News reserves the right to reject words offend individuals or organizations; words left habits and customs, law violations. Readers discuss accented Vietnamese. Comments do not necessarily reflect the views of the Environmental News. Thank you for your contributions and cooperation of)
Cat- center 3
Cat- center 4
  University student makes bricks from scrap paper

University student makes bricks from scrap paper

( - Nguyen Cao Hoang Sang, a student at HCM City Architect University, has created green building materials from scrap paper after seven months of research.

  Vietnamese farmers make solar-powered boat

Vietnamese farmers make solar-powered boat

( - Farmers in the Mekong River Delta have invented boats that can run smoothly with no noise or pollution to the environment, and are especially suitable to serve ecotourism.

Cat- center 6
  BAKV officially launches its high-end smartphone

BAKV officially launches its high-end smartphone

( - BKAV – Vietnam’s leading network security firm – launched its first smartphone Bphone on May 26, after many advertising campaigns.

Cat- center 7