Wastewater from sewer gates has been poured directly into the Cam Le River of Da Nang, turning the water blackish with foul smell.
Along a kilometer-long section from Hoa Xuan Bridge to Nguyen Tri Phuong Bridge in Cam Le District, four sewer gates discharge wastewater into Cam Le River. Three of them are located at Thang Long Street in the west side of the river, while the other one is at Ton That Duong Ky Street of the east side.
Thanh, 53, constantly coughed as he rode his boat past a sewer section, even though he already had a mask on.
“The sewer gates cause pollution, even fish cannot survive,” he said, adding that he had seen plenty of dead fish in the polluted section.
The sewer gates can be easily seen with the naked eye during low tides, Thanh said. Many of them are obstructed by surrounding weeds, but people in certain vantage points can see streams of wastewater being poured into the river and eventually flowing towards the Han River, and finally the sea, he added.
Untreated wastewater discharged into Da Nang riverNước thải chưa xử lý xả ra sông ở Đà Nẵng
Nguyen Thi My Gion, head of the wastewater environment technology department under the Da Nang Drainage and Wastewater Treatment Company, said that among the four sewer gates, only the wastewater discharged at one has been treated.
The sewer gate near the Nguyen Tri Phuong Bridge is supposed to transport wastewater to Hoa Xuan treatment plant, but the sewage has overflown into the river. The sewer at Ton That Duong Ky Street meanwhile is not her company’s responsibility, she said.
On the reason why the treated wastewater still turns out black, Gion said the wastewater is processed at the Hoa Cuong treatment plant whose technologies are outdated.
Nguyen Thi Duc, deputy director of the Da Nang Drainage and Wastewater Treatment Company, said there are 17 sewer gates on Thang Long Street running along the Cam Le River, while there are 28 gates on Bach Dang and Tran Hung Dao Streets running along Han River. There are also several sewer gates at new urban areas that have not been managed yet.
Da Nang has been collecting both wastewater and rainwater within the same system, with six treatment plants capable of treating 300,000 m3 of water a day.
“When it rains heavily, the plants cannot treat all the wastewater, so we have to accept the fact that some wastewater would be poured into the rivers and the sea,” Duc said.
While the company waits for the Hoa Cuong and Hoa Xuan treatment plants to be upgraded, it would build sand embankments at the sewer gates to increase the threshold and keep the wastewater inside the sewers during peak hours.