Ho Chi Minh City clears some 5,000 cubic meters of sludge daily from its sewage system but dumps it untreated at other places, posing pollution risks, experts warn. Nguyen Trung Viet, head of the city Department of Natural Resources and Environment’s Solid Wastes Management Division, said only around 210 cubic meters are dumped at the Hoa Binh waste treatment plant in Binh Chanh District with the rest disposed of at vacant sites around the city. The sludge generated by the clean water supply system is disposed of in rivers and canals. The sludge includes around 200 cubic meters generated by waste-treatment plants and 800-1,000 cubic meters by construction projects. But Viet admitted that not all sludge contain substances harmful to the environment, only those from industrial waste – others, like sludge generated by canal dredging, rarely contain toxic substances. Over 60% of sludge generated from waste-treatment systems at companies and industrial areas contained substances harmful to the environment and human health, a recent study by Dr. Nguyen Phuoc Dan, who works for a research institute under the Ministry of Natural Resources and Environment, found. The city has begun a project for treating sludge, including at two treatment plants in Binh Chanh and Cu Chi Districts, which is expected to be completed by the first quarter next year.
