China will step up supervision and management of sewage outflows, according to a circular released by the State Council on March 2.

The circular said investigation of sewage outfall along seven estuaries, including the Yangtze River, Yellow River, Huai River, Hai River, Zhujiang River and Taihu Lake, should be completed by the end of 2023.

And treatment of all sewage outflow in main basins should be completed, with an improved legal system, scientific technical system and effective management system established by the end of 2025, the circular said.

The investigation should clear information of the distribution and number of sewage outfall, features and traces of sewage discharge, and pin down dischargers.

According to the circular, sewage outflow will be classified into four categories, including industrial discharge, urban sewage-treatment plants, agricultural discharge, and other purposes.

Sewage flows should be banned in areas calling for special protection, highlighting drinking water sources and natural reserves. And those located in the pipe network of urban sewage collection should be converged and connected to the pipe network.

Planning ecological and maritime protection at all levels should take into consideration distribution of sewage flows and requirements for management and control.

Outflows  from sewage plants in industrial and mining enterprises and urban sewage-treatment plants should go through strict approvals, the circular stressed.

In addition to robust supervision and management, uniform regional information platforms for sewage outflows should be established.

The circular also stressed a stringent assessment and accountability system, robust scientific support, like remote sensing monitoring and aerial surveys, and public supervision.