While samples taken from two of Hanoi’s water plants contain high levels of ammonia, the concentrations of other potentially harmful substances are within the safety zone, the city’s health department said.

The test was sparked by recent complaints from local scientists that the water supplied by several plants contained excessive ammonia and even toxic arsenic.

In the health department’s opinion, the high concentration of ammonia cannot harm human health. Furthermore, the levels of substances like arsenic, nitrate and nitrite are acceptable.

Tuan attributed the extreme ammonia concentration to both suppliers and households, saying that underground water pipes made of cement and home water tanks could well be the culprits.

It is vital to keep up with new technology and adapt to the Ministry of Health’s ammonia standards, Tuan added.

Dr. Tran Van Nhi from the National Institute of Chemistry found an ammonia concentration of 10 mg/l in Hanoi’s tap water when he was testing his institute’s idea of using microorganisms to get rid of the chemical.

He tested more samples after a rash of complaints about Hanoi’s tap water, one being that meat boiled in the water remained red no matter how long it was cooked.

Scientists warned a couple of years ago that the city’s tap water was full of ammonia, yet the agencies responsible for public health failed to do any testing or otherwise deal with the problem, Dr. Nhi said.

While ammonia poses little direct risk to human health, it can react with other substances in the water to create carcinogens, according to the scientist.

This possibility prompted the health department to take samples from a dozen water plants in Hanoi for testing, with the Ha Dinh and Phap Van plants being first on the checklist.

Since then, the city’s Construction Department has told the Hanoi Clean Water Trading Company to reduce the supply of water from these two plants, and supplement it with water from other plants, a local newspaper recently quoted the department’s director Le Van Duc as reporting.

Source: Tuoi Tre