Water supply in downtown Hanoi was disrupted on Sunday as a major pipeline ruptured for the 21st time over the past five years.
Vinaconex, the state-owned construction company responsible for the Song Da water pipeline, said it found “a leak” on Sunday morning.
Water supply was cut off soon after that and was resumed in the evening.
Hanoi’s construction department last month warned about possible pipe ruptures, saying the city really needs a stable supply of clean water for the summer.
The $70-million Song Da pipe system provides more than 200,000 cubic meters a day, or nearly a quarter of the clean water supply in the city, which is home to 7.6 million people.
It has been breaking down again and again since 2012, three years after it was put into use. The last rupture was in October last year.
A police investigation last year found Vinaconex had used substandard pipes purchased from a Chinese contractor.
Fourteen people were accused of violating construction and investment regulations. Criminal charges were later dropped against five of them, who reportedly have good personal records and have cooperated with the investigators. The top prosecutor's office in August last year questioned this decision.
The rest are awaiting trial.
The company last year signed a contract to use pipes from another Chinese company to fix the unreliable system but backed out of the deal after the government raised concerns over quality standards.
Work has barely started on the second pipeline.