With the deepening of the survey and remediation of rain and sewage mixing in Changning District, the situation, hazards and types of rain and sewage mixing have emerged one by one. Today, let's trace the root cause with "Ningning" and discover the root causes of rain and sewage mixing.
Weak awareness of environmental protection
●Shops along the street dump kitchen waste and food scraps into the stormwater pipe network;
●In the living area of the construction site, some workers washed and washed their clothes next to the rainwater gutter, or poured food residues into the stormwater pipe network;
●Some residents in the residential area have a high incidence of illegal construction and private connections, and the wastewater from toilets, kitchens and other places is connected to the rainwater riser or discharged into the open ditch;
●Non-standard open-air car washes in car washes, illegal sewage discharge from temporary food stalls, and garbage dumping are the sources of mixed rain and sewage problems.
The stormwater and sewage pipe network is not set up according to the specifications
●In the living area of the construction site, the pipe network is not fully covered, or there is only a rainwater pipe network without a sewage pipe network, and the wastewater from grease traps and septic tanks is outsourced through pumping. Waste water such as sinks, kitchens and bathrooms are discharged into the nearby stormwater network;
●Waste water such as washing machines and sinks in the balconies of residential buildings in some residential communities is discharged into rainwater risers;
Example: This picture shows a rainwater well in a community in Changning District, the rainwater well has a flow of water on a dry day, the sewage foam is abundant, and there is an obvious smell of washing powder. It is preliminarily judged that the balcony sewage is mixed into the rainwater pipe of the community.
●There is no sewage pipe network next to the sink, and the wastewater is directly discharged into the nearby rainwater well.
The stormwater and sewerage network has been undermaintained for a long time
●Some serious rain and sewage mixing problems are caused by structural damage such as pipe rupture, dislocation, and deformation. If the pipeline is not maintained for a long time, it will gradually age, and under the influence of external forces, problems such as rupture, dislocation, and deformation will occur, which will lead to sewage leakage. If the leakage point appears in the inspection well where the rainwater and sewage pipes cross, or near the rainwater inspection well, the sewage will flow directly or seep into the rainwater inspection well through the well wall, and finally flow into the rainwater pipe network.
●Some sediment, leaves, garbage, etc. will enter the rainwater pipe network with the rainwater, and long-term dredging and dredging will lead to the blockage of the rainwater pipe network, the functional defects of the pipeline, causing poor drainage, rainwater overflow, and finally entering the sewage pipe network, resulting in the mixing of rain and sewage, and bringing pressure to the downstream sewage treatment plant.
●Due to the strong viscosity of grease garbage and feces, the sewage pipeline is more likely to be blocked, and the harm of sewage overflow is greater, which not only deteriorates the surrounding environment, but also enters the nearby rainwater pipe network, causing serious rain and sewage mixing.
Example: This picture shows a sewage well in a community in Changning District, the sewage well is located at the entrance of the community and vegetable market, and the sewage well is seriously blocked.
●The internal rain and sewage pipe networks of the old commercial streets that have been verified are unmaintained all year round, and the pipes are damaged, blocked, and overflowing. During the inspection, it was found that due to poor drainage of the internal pipe network, some merchants directly dug up and chiseled the sewage pipes and connected the sewage to nearby rainwater wells.
The source is the District Construction Management Committee
Finishing: Xu Monroe
Editor: Cheng Qian
Editor-in-charge: Wang Bo
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