No privately connected mixed sewage pipes were found, Lanzhou reported the investigation of "sewage discharge into the Yellow River" again: sediment sludge in the pipes flows into the Yellow River
On September 7, a netizen released a video of sewage discharged into the Yellow River on the southeast side of the Qilihe Yellow River Bridge in Lanzhou on Tiktok, Today Toutiao and other platforms, which attracted wide attention.
Video screenshot
On the evening of September 8th, the Housing and Urban Rural Development Bureau of Lanzhou City and the Ecological Environment Bureau of Lanzhou City issued a notice: after on-site verification, it was found that there was indeed a phenomenon of yellow sewage discharge in the area. The housing and construction, ecological environment and other departments immediately organized personnel to conduct traceability and investigation along the pipeline to the site. At around 10 o'clock on the 8th, the phenomenon of yellow sewage discharge has basically disappeared.
On the afternoon of September 9th, the two departments of Lanzhou City mentioned above issued another notice, and netizens reported that the reason for sewage discharge into the Yellow River has been investigated.
According to reports, after on-site tracing and investigation by staff, it has been confirmed that the drainage pipeline on the southeast side of the Qilihe Yellow River Bridge reported by netizens is a rainwater pipe. The starting point of the pipeline is at the intersection of Gongjiawan, passing through Wushan Road, Wuwei Road, the western section of Guazhou Road, Dunhuang Road, and the east of the Qilihe Yellow River Bridge into the Yellow River channel. The outlet of the pipeline is a DN1500 reinforced concrete pipe. This rainwater pipe is mainly used to collect rainwater from the road surface, branch roads, small streets and alleys, units, and residential areas along the line. It is used for normal drainage during rainy weather. There are a total of 39 rainwater collection wells along the pipeline, which are regularly cleaned by the Lanzhou Municipal Service Center. Due to untimely cleaning of the sediment in the rainwater well and pipeline, coupled with high summer temperatures, sludge is formed after fermentation.
On the early morning of September 7th, heavy rain began in Lanzhou City, washing away the sediment in the pipeline and flowing into the Yellow River at the discharge outlet, forming a black water zone. After the rainfall ends, the outflow of rainwater from the pipeline ends, and there is no sewage discharged.
On September 8th, after the traceability work was completed, the Lanzhou Housing and Urban Rural Development Bureau instructed the Municipal Engineering Service Center to clean and remove all rainwater wells along the pipeline. The cleaning and removal work has now been completed. At the same time, an investigation was conducted on the pipeline network along the route, and no phenomenon of privately connecting and mixing sewage pipes was found.
Two departments in Lanzhou city have stated that the next step will be to carefully learn from the lessons of this pollution discharge problem, establish a long-term mechanism, and work together with the local government, the Municipal Urban Management Commission and other units to increase the inspection and rectification of the municipal pipeline network along the Yellow River, in order to prevent the occurrence of sewage discharge from the source. The Municipal Engineering Service Center has opened a supervision hotline, and citizens are welcome to provide feedback on drainage issues along the Yellow River at any time.
