The water quality in the Thi Vai River in Dong Nai Province near HCM City has improved, allowing fishermen to now catch and farm fish and other species in it.
The river, which flows downstream of the Dong Nai River, was considered dead just six years ago because of pollution caused by untreated wastewater discharged by factories.
Tran Van Tien, a fisherman in Long Thanh District’s Phuoc Thai Commune, said the water used to be black because of the waste, which also caused the death of fish, shrimp, and other species.
After Taiwanese company Vedan was found in 2008 to have been directly discharging untreated waste into the Thi Vai for years, local authorities improved management of wastewater and the river has improved as a result, he said.
“Fishermen can now catch more fish.”
Phuoc Thai Commune now has 300 households that fish in the river and raise fish and other creatures with water from the river, according to the commune Famers Association.
Thousands of households that had ceased farming of shrimp and other aquatic species along the Thi Vai in Dong Nai and Ba Ria – Vung Tau provinces and HCM City have now resumed.
In recent years Dong Nai authorities have taken many measures to improve treatment of wastewater at industrial parks and residential areas before it is released into the river.
Tests in 2013 and earlier this year showed that the river’s water quality is good enough for aquatic species to live in it.
But, admittedly, it is yet to meet certain criteria.
Nguyen Ngoc Thuong, deputy director of the Dong Nai Province Department of Natural Resources and Environment, said that occasionally biological oxygen demand (BOD) and chemical oxygen demand (COD) exceed permitted levels, but not often.
Many industrial parks are also located along the Dong Nai River.
Waste from Bien Hoa 1 Industrial Park, the country’s first, in Bien Hoa city is a major source of pollution since most companies in the park lack wastewater treatment facilities.
Dong Nai authorities plan to convert the 330ha park into a modern urban –commercial – services zone by 2020, and the factories are set to move out of there.
They have thrown the book at companies violating environmental regulations and are setting up large wastewater treatment plants in industrial parks.
They have also set up many automatic observation stations on the Dong Nai and Thi Vai including at 18 industrial parks that have large, efficient waste treatment plants and 19 firms located elsewhere that generate large quantities of wastewater.
Thuong said the province would soon set up six more such stations on the two rivers.
In the province, around 500,000cu.m of wastewater is produced every day by industries and homes, according to the Department of Natural Resources and Environment.