The government has said that 200,000 people were adversely affected by the toxic leak off the central coast which killed millions of fish earlier this year.
It says that it has learned lessons from the disaster and attempted to reassure the public that a similar environmental catastrophe would not happen again.
Environmental groups have criticised the government for a lack of transparency over the mass fish poisoning, which was caused by a leak from a Taiwanese owned steel plant, and say officials have been slow to release information and take responsibility.
A government report submitted to the National Assembly said that 41,000 fishermen were amongst those whose livelihood was damaged, according to state controlled media.
It said that an estimated 115 tonnes of dead fish had washed up on beaches in central provinces and that more than 200 tonnes of farmed fish and shellfish were also been killed.
The Prime Minister, Nguyen Xuan Phuc, earlier tried to reassure the public that the government had learned from the disaster, which first became apparent in April when dead fish washed up on central beaches, and would take steps to prevent a repeat.
Speaking after being re-elected by newly installed members of the National Assembly, he said the mass poisoning served as a lesson about how to manage foreign investment projects.
The Taiwanese conglomerate, Formosa Plastics, accepted, after a government investigation, that a steel plant built by its Vietnamese subsidiary had poisoned the waters off Ha Tinh Province.
It was forced to admit that the plant had illegally discharged toxic chemicals into the sea. It agreed to pay $500 million in compensation.
Mr Phuc said the government must ensure there was no repeat of such an environmental catastrophe: “We must review large projects as well as closely monitor their environmental commitments,” he told the assembly.
“We must not develop at the cost of destruction of the environment,” he said.
Experts complain, however, that many questions remain unanswered about how the disaster was allowed to happen, and why government regulation failed so abjectly.
They suspect that government and Communist party officials, in this case and others, are too closely involved with foreign companies that bring multi-billion dollar investments.
Search for scapegoat ?
A member of the National Assembly’s economic committee, Vo Kim Cu, has been subject to criticism for his role in the development of Formosa’s steel plant in Vung Ang on the coast of Ha Tinh.
A senior figure in the provincial government at the time, he was seen as a key backer of the project.
Cu broke his silence to tell the Tuoi Tre newspaper that he had always insisted that the company comply with environmental protection standards.
He said that it was up to other agencies to ensure that the standards were met.
Cu was also implicated in a decision to grant the company an extended 70 year lease.
Some activists, however, suspect that the assemblyman is being set up as scapegoat for the government’s failings.
They say that the Communist party under its leader, Nguyen Phu Trong, bears ultimate responsibility for all such major decisions.
The campaign for full accountability looks set to continue, while thousands of fishermen in the four affected provinces attempt to rebuild their livelihoods after one of Vietnam’s worst environmental disasters.