Authorities in the Central Highlands province of Kon Tum have suspended the construction of a VND200-billion (US$9.51 million)-plus dam after a portion of it collapsed last week, killing one person.
Speaking to the press earlier this week, Bui Van Cu, vice director of Kon Tum Department of Industry and Trade, said they regard incident at the Dak Mek 3 Hydropower Plant as "serious" and proposed that related agencies conduct quality inspections.
Part of the dam in Dak Choong Commune, Dak Glei District, suddenly broke on November 22, crushing Nguyen Viet Hung to death. The 28-year-old worker was driving by when the collapse occurred.
The collapsed segment was estimated to be 80 meters long, 20 meters high and 1.5 meters thick, according a report issued by project's contractor, the Hong Phat Mechanics and Construction Company.
Speaking to Vietweek, Le Ba Thanh, director of the project's investor, the Hong Phat Dak Mek Hydropower Company, the dam failed because it could not withstand the large amount of rock, estimated at 700 cubic meters, which was poured on it during the height of construction.
But he also said that they are still waiting for the official conclusions from related agencies.
Earlier, Thanh was quoted by Tuoi Tre (Youth) newspaper as saying that the dam was damaged by a dump truck that crashed into its body.
"We guaranteed that the dam was built with quality and in accordance with the design," he said, acknowledging that the contractor was their member company.
However, in an interview with the newspaper, Le Van Thinh, chief of the National Agency for Construction Work's Quality Assessment, ruled out the possibility that a crash by a truck, despite weighing 60 tons as claimed by the investor, could have caused the fatal incident.
The design of a dam had to be made with considerations about sudden pressures that could be caused by trucks colliding with the dam during construction, he said.
"Therefore, first of all, the culpability of the contracted designer and the design itself must be reviewed," Thinh stressed.
If it was true that a truck collision could break a "thick concrete wall," there must have been something wrong with the design, according to the official.
Secondly, he said, it must be determined whether the contractor made mistakes, because some workers claimed that cracks had appeared prior to the accident and police did in fact find cracks in other sections of the dam.
According to Thinh, cracks could be caused by poor quality concrete or a faulty foundation.
Nguyen Bo, director of Kon Tum Department of Industry and Trade, told Vietweek that the investor did not report the accident to the department until three days later.
Such accidents are supposed to be reported to district authorities and the Ministry of Construction within 24 hours, Thinh said.
Construction on the dam got underway in March 2009 and some 80 percent of the work had been completed at the time of the collapse, according to Thanh.
The dam was scheduled to begin operating in the first quarter next year with an expected output of 7.5 MW and a reservoir capable of storing over 1.7 million cubic meters, but the accident is likely to delay its start date by more than two months.