It is strictly forbidden to connect rainwater and sewage pip

According to a recent report from the Department of ecological environment of Zhejiang Province, the engineering construction standard of Zhejiang Province, technical standard for urban rainwater and sewage diversion and reconstruction (Draft for comments), was recently released. The standard consists of 7 chapters and 8 appendixes, which are applicable to the investigation, design, construction, acceptance, operation, maintenance and evaluation of the urban rainwater and sewage diversion and reconstruction project in Zhejiang Province.
In order to standardize the transformation technology of rainwater and sewage diversion in Zhejiang Province, do a good job in the classified management of rainwater and sewage and reduce the total amount of sewage treatment, the standard specifies that the rainwater and sewage diversion system should be adopted in the urban drainage system, and the existing intercepted combined drainage system should gradually implement the transformation of rainwater and sewage diversion. The urban drainage system shall be equipped with a complete rainwater and sewage drainage pipe network and its auxiliary facilities. The direction of the pipeline shall be clear. It is strictly prohibited to mix rainwater and sewage pipes and channels. The transformation of rainwater and sewage diversion should include investigation, design, construction, acceptance, operation, maintenance and evaluation.
On the basis of a comprehensive investigation of the original drainage facilities, the rainwater and sewage diversion transformation should be comprehensively combed, systematically designed, and properly connected with the original pipeline. Solid and durable pipes and intelligent management equipment should be used in the transformation project of rainwater and sewage diversion. The quality of sewage discharged into the urban sewage pipe network shall comply with the current national standard water quality standard for sewage discharged into urban sewage (GB / t31962). The drainage facilities management unit shall establish a patrol and maintenance mechanism, regularly inspect and maintain the rainwater and sewage pipe network, timely rectify the problems found, and ensure the normal operation of the drainage system.
According to the principle of "drainage should be done as much as possible" and "inspection should be done as much as possible", drainage areas should be divided based on drainage system units or streets and town administrative areas before investigation. The survey object shall include sewage source and public drainage facilities in the area. For the living quarters, it is necessary to focus on the investigation of the rainwater and sewage diversion and the supporting facilities and sewage treatment of the wastewater and sewage produced by the supporting public construction units. The industrial enterprises (parks) should focus on the investigation of the quality, classification (pre-treatment), emergency plan and the pre-treatment of sewage and wastewater in the affiliated facilities of related enterprises based on the investigation of rainwater and wastewater diversion.
Among them, the survey of "six small industries" should include the drainage facilities and sewage pretreatment facilities built by drainage households in small industries such as catering, car washing, beauty salon, washing, hotel and bath. On the basis of the investigation of rainwater and sewage diversion, the following contents are mainly investigated: sewage pretreatment and connection of oil separation facilities and oil-water separation devices for catering sewage; sewage pretreatment and connection of grit chamber and oil separation facilities for car washing and automobile repair; sewage pretreatment and connection of hair collection wells (devices) for bathing, hairdressing and accommodation Take over; check and maintain daily drainage facilities and pretreatment facilities.
The design shall follow the principle of "overall consideration and local conditions", and fully consider the discharge demand of rainwater and sewage. The existing drainage facilities should be used in the design to reduce the project cost. Under the guidance of relevant planning, the design of main and secondary sewage pipes should take into account the requirements of sewage access around the upstream road and elevation connection of downstream sewage system, and strengthen the systematicness of sewage pipe network. Pipes shall be comprehensively compared and selected to ensure safety, applicability, economy and easy operation and management. Rigid pipes shall be used for the newly reconstructed D300 and above pipes under the carriageway.
For the reconstruction area of existing rainwater and sewage pipelines, the problems such as wrong connection, mixed connection and leakage shall be rectified and repaired according to the list of problems, and the sewage intercepting facilities of combined system shall not be set or added; for the reconstruction area of existing sewage intercepting facilities of combined system, the source shall be identified, one by one shunting shall be cancelled. Limited by objective conditions, if two pipelines cannot be buried at the same time in the reconstruction area, under the condition of ensuring sewage collection, rainwater can be discharged by scattered drainage or rainwater ditch (channel), and confluence is strictly prohibited. For the community without septic tank, septic tank should be added; for the community with insufficient conditions, grille should be added before connecting to the reserved well of municipal sewage. Roof rainwater pipe shall be set independently and connected to outdoor rainwater system.
For the community supporting public construction units without drainage system or with drainage system defects, the drainage system shall be set up separately to connect to the municipal pipe network, and the corresponding pretreatment facilities shall be set up, and the pipeline shall not be shared with the community; for the small community supporting public construction units with drainage system set up and connected to the drainage pipeline of the community, it is advisable to separate and transform them to eliminate the adverse impact on the drainage of the community. The Industrial Park shall strictly implement rainwater and sewage separation, complete rainwater and sewage collection system, reasonable pipe network layout and normal operation. According to the regulations, the sewage centralized treatment facilities that meet the requirements shall be built to keep normal operation and make the sewage discharge up to the standard.
The initial rainwater collection pool shall be established in the polluted area, and the polluted initial rainwater shall be discharged or incorporated into the municipal sewage pipe network after reaching the standard. Independent sewage pipe network and treatment system shall be established in the industrial park, and the pipe network shall be free of structural and functional defects such as wrong connection and damage. The sewage from catering industry and other industries producing oil pollution shall be discharged after pre-treatment of oil separator; if the small catering units are unable to set up oil separator due to conditions, they shall set up small oil-water separator.
The car washing industry shall set up intercepting ditch around the car washing operation area according to the requirements, discharge the waste water into the oil separation sedimentation tank for pretreatment, and then discharge it into the municipal sewage pipe. The sewage from hotels, beauty salons, baths and other business places shall be discharged into municipal sewage pipes after pretreatment by hair collection wells (devices). The sewage treatment process of medical institutions should be determined according to the nature of sewage, discharge conditions and other factors, when discharged into the terminal