China News Service, October 26. According to the WeChat official account of the Ministry of Ecology and Environment, in September 2021, the Fourth Central Ecological Environmental Protection Supervision Group inspected Guangdong found that Zhongshan City did not pay enough attention to water pollution control work, and the progress was slow. The gap in the network is large, and a large amount of sewage is discharged directly into the river without being collected and treated, and the inland river gushing is seriously polluted.

1. Basic situation

　　Zhongshan City covers an area of ​​1,784 square kilometers, governs 23 towns and streets and 1 state-level development zone, manages a population of nearly 6 million, has many water systems, dense river networks, and more than 1,000 inland rivers.

The centralized collection rate of domestic sewage in Zhongshan City from January to July 2021 is only 45%, and a large amount of sewage is directly discharged every day.

Among the 1,028 inland rivers monitored by the city in the second quarter of 2021, 459 inland rivers inferior to Grade V reached 459, accounting for 44.6%; of the 254 inland rivers that have designated water environment function zones, 126 failed to meet the water quality target , Accounting for 49.6%.

Zhongshan City does not understand this in place and does not pay attention to its work. The construction of sewage collection pipe network is slow. It will not be until 2020 that water control is placed in an important position, deployment and implementation are carried out.

Two, the main problem

(1) Emphasize the emphasis on the work, and the progress of water control work is slow

　　In July 2018, the 38th executive meeting of Zhongshan City requested that we should make every effort to promote the improvement of black and odorous (not up to standard) water bodies to ensure that all projects entered the implementation stage by the end of November of that year; the 83rd meeting of the Zhongshan Municipal Party Committee in August 2018 proposed that, Ensure that the goal of basically eliminating black and odorous water bodies in central urban areas and inferior Class V water bodies in various towns and districts will be achieved by 2020.

　　The inspector found that from the second half of 2018 to the first half of 2020, Zhongshan City had insufficient planning and deployment, insufficient tackling difficulties, and slow progress in water control.

The water remediation work in 8 towns and streets including the central city and Dayong Town involves 158 inland rivers. It is planned to complete the remediation before December 2020, but only 16 rivers have been completed after the expiration date. As of the inspection period, 134 rivers are still under remediation. , 8 have not yet entered the construction site, and the progress is seriously lagging behind.

The other 16 towns and streets (including development zones) are involved in the improvement of 938 rivers. As of the inspection period, only 127 have entered the site for construction, accounting for only 13.5%.

Among them, the Xiaoyinyong River Basin Comprehensive Improvement Project was approved by the municipal government's executive meeting as early as August 2018. However, only survey work has been completed so far. Of the 30 major rivers in the basin, 24 are still inferior to Class V, and some Still severely black and smelly.

(2) The pipe network is missing, and the phenomenon of direct sewage discharge is prominent

　　According to Zhongshan City's calculations, there is a gap of 15,75 kilometers in the city's domestic sewage collection pipe network.

Among them, the domestic sewage pipe network gaps in the Torch Development Zone, Dongfeng Town, Tanzhou Town and Sanxiang Township reached 282 kilometers, 131 kilometers, 144 kilometers and 134 kilometers, respectively.

The sewage pipe network lacks maintenance and management, and the problems of siltation, damage, wrong connection, and missing connection are common. Affected by this, the city's domestic sewage is directly discharged, leaked and mixed with clean sewage. The operation load and water inflow of the domestic sewage treatment plant The phenomenon of "double low" concentration is widespread.

In the first half of 2021, 7 of the city’s 22 domestic sewage treatment plants have an operating load of less than 60%, 9 of the influent chemical oxygen demand concentration is below 120 mg/L, and 10 of the influent biochemical oxygen demand concentration is below 60%. 60 mg/L, much lower than the designed influent concentration.

As of August 2021, the gap in the sewage pipe network of the non-central group of Zhongshan City has reached 1,535 kilometers

　　Random inspections by the inspection team found that many inland rivers in Zhongshan City were seriously polluted, and many sewage outlets along the river were directly discharged into the river.

Among them, Qinggangyong in Dayong Town, Tuguayong in Shaxi Town and Baimiaoyong, Shabianyong and Sanyong in Torch Development Zone showed black and odorous water bodies. Monitoring showed that the ammonia nitrogen concentration was between 9.49-27.3 mg/ Liters, the highest is 26.3 times higher than the surface water class III standard.

Shaxi Town has long used the terminal interception method to pump sewage from Langxin Fourth Canal to the sewage treatment plant for treatment. Langxin Fourth Canal has become a "sewage receiving pipe", and the water is dark and smelly with peculiar smell.

Since June 2020, although Shaxi Town has carried out sewage plugging and pipe network construction, the drainage capacity of the pipe network is still insufficient. A large amount of sewage overflows at the peak of water consumption, and the water quality of Langxin Fourth Canal is still obviously black and smelly.

On September 8, 2021, a random inspection by the inspection team found that many inland rivers in Zhongshan City were seriously polluted

On July 27, 2021, the inspection team found that the fourth channel of Langxin was full of domestic sewage and the water body was black and smelly.

(3) Inadequate measures and unstable effects of some water bodies

　　The remediation project of black and smelly water bodies in Dajiaoyong and Lianxingyong of Shiqi Sub-district will be completed in June 2020.

However, in July 2021, the inspection team found out that the water bodies of the two rivers were black with obvious peculiar smell. The ammonia nitrogen concentration at the junction of the Lianxingyong open and culvert channels was as high as 18.6 mg/L, which was a severe black and odor.

The inspection site found that Dajiaoyong and Lianxingyong rely on the exchange of rising and falling tides and water supply from the Shiqi River to improve the perception of water quality.

On July 30, 2021, the inspection team used drones to shoot, the water body of Dajiaoyong became black, which was in obvious contrast with Shiqi River

Three, cause analysis

　　Zhongshan City has insufficient understanding of water pollution control, insufficient attention, inadequate planning and deployment, insufficient pressure transmission, and slow work; the relevant departments and towns of Zhongshan City have insufficient proactive actions in water pollution control, and the implementation of the implementation is not effective, resulting in passive water control work, and the city's rivers are gushing. The pollution problem is still serious.

　　In response to the problems pointed out by the inspection team, Zhongshan City quickly convened a legislative reform work meeting to deploy rectification work, and carried out tackling actions against the problematic rivers.

At present, the improvement of rivers is progressing steadily.

　　The inspection team will further investigate and verify the situation, and do a good job of follow-up inspections as required.