The centralized wastewater treatment plant of the Long Thanh Industrial Park in the southern province of Dong Nai has been caught polluting a canal for four years, an environmental agency said.
After several months of investigation, the Natural Resources and Environment Institute under the HCMC National University has concluded that the poorly-treated wastewater discharged by the plant has caused serious pollution to the Ba Cheo canal.
The plant, which is in charge of handling wastewater from 42 enterprises in the park, was an affiliate of Long Thanh Sonadezi Joint Stock Company.
After testing the wastewater samples taken from the plant, the department concluded that those samples exceeded the country’s allowable limits on colour, chemical oxygen demand (COD), biological oxygen demand (BOD), Fe, N, NH4+, and some other chemicals.
The institute launched the investigation upon requests from the department and the national environmental police, which had received many complaints from local residents about the pollution.
As reported earlier, on August 3, 2011 a team from the Ministry of Public Security’s Environmental Crime Prevention and Control Department caught the plant releasing about 9,300 cubic meters of black, stinking wastewater into the canal, which is the main water supply for about 500 hectares of farmland in the district’s Tam An commune.
The police found a sewerage system buried underground to unload the waste from the plant into the canal.