Local authorities Tuesday warned people not to use tap water for drinking or cooking because its source was unsafe. 

Following the warning, 1.5-liter, 5-liter and 20-liter bottles became bestsellers in local stores and supermarkets in Thanh Xuan and Hoang Mai Districts.

Minh Hanh, who lives in Thanh Xuan District, said she made dozens of phone calls to vendors of 20-liter bottles in the area, but each time, the answer was that it was out of stock

"From the lobby to the elevator, water bottles can be found every corner as all households store them for daily use during this time," Hanh said.

After failing to get clean water from water tankers Tuesday night, Tuan, a resident in Hoang Mai District, scoured supermarkets to buy bottled water. However, he was forced to buy a box of 24 bottles of 0.5 liters each as there were no large bottles on supermarket shelves.

A supermarket employee said they had stocked a large amount of water bottles yesterday, but were sold out by evening.

Bottled water flies off supermarket shelves on Tran Duy Hung Street
in Hanoi on October 16, 2019. Photo by VnExpress/Ngoc Thanh.

An employee of a bottled water distributor in Hanoi said it currently has more than 200 orders of 20-liter water bottles but the item is out of stock. In some areas, the price of water bottles has increased to VND60,000 ($2.55) a 20-liter bottle.The supermarket cannot guarantee that the item would be available by Wednesday afternoon because all suppliers are now overloaded.

At supermarkets, filtered water is still sold at the listed price of VND23,000-25,000 ($0.99-1.07) for a five or six-liter bottle and VND9,000-12,000 ($0.38-0.51) for a 1.5 liter bottle. 

Many eateries are also affected by the situation. Nghia, owner of a noodle shop in Hoang Mai district, said that it has water cost him VND500,000 ($21.54) a day since Monday.

A senior government official confirmed on Tuesday that the water supply across the city’s south-east has been contaminated with styrene, a carcinogenic.

The smell first appeared after a truck dumped oil into a branch of the Red River, a few hours north-east of Hanoi on October 8.

Hoang Van Thuc, deputy head of the Vietnam Environment Administration, called it a "serious and irresponsible act of vandalism". The water pollution has affected 250,000 housesholds in Hanoi.