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- Excavation and temporary use of public sewers
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Excavation and temporary use of public sewers
Last Updated August 15, 2022
- When we perform the following drainage including drainage for construction, and use public sewer temporarily, please submit public sewer temporary use permission application and receive permission of Public Works Office.
- （１） Spring water, rainwater, and drainage for construction work associated with civil engineering and construction work (for spring water and rainwater are used with a pot).
（２） Wastewater from temporary toilets and hand-washing areas installed in temporary offices.
（３） Accumulated water from caretaker holes such as telegraph telephones, electricity and gas.
（４） Wastewater associated with other construction work.
In addition, when applying, the drainage method etc. must conform to the attached standards. In addition, industrial waste cannot be drained. - When digging near the public sewer for civil engineering or construction work, or if you are going to dig deeper than drain pipe, please submit a registration form digging near the public sewer.
- Drainage method
- （１） When discharging in a confluential area, flow directly into the connection basin.
（２） When discharging in a diverted area, the flow directly into the sewage connection basin.
（３） Drainage associated with construction on the road (including underground) can be connected to a human hole by installing a mounting pipe. However, please consult with Public Works Office regarding the connection location, construction method and restoration method.
（４） If there is no connection basin on the premises or near the site, apply for self-financing construction to Public Works Office, install the connection basin and mounting pipe, and submit a temporary application form. - Structure of drainage facilities
When discharging wastewater for construction, install drainage facilities as follows. (excluding temporary office wastewater and temporary toilet drainage)
（１） Public sewerage facilities, road facilities, etc., and traffic.
（２） In the drainage facility, install a sedimentation tank that meets the following standards.
A. A rectifier plate, cough, etc., so that it does not cause disturbance by running water.
I. The sedimentation tank has a structure of two or more tanks
C. In principle, the average flow velocity is 0.3 m/s or less.
D. As a rule, stay time is 30 seconds or more.
O. Mudra is 60cm or more
（３） When discharging alkaline or acidic sewage, set up a neutralization tank and adjust it before discharging. The neutralization tank must have a function to automatically stop the power pump when the water quality exceeds the standard value in principle.
（４） The sedimentation tank shall have a structure in which the flow rate can be measured in principle. - Water quality standards and drainage volume certification
（１） Water quality such as drainage for construction is based on the regulations concerning conservation of Yokohama City living environment and standards such as the Yokohama City Sewerage Ordinance, in addition to those listed in the following table. Water quality should be inspected from time to time, and appropriate management should be performed to comply with laws and regulations.
（３） When we violate laws and ordinances or the above standards and permission conditions, or when the city deems it necessary, we may remodel, relocate or remove drainage facilities. The expenses required in this case shall be borne by applicant.Water quality standards for construction wastewater Items Processing area
(From flowing into the sewage treatment plant)Untreated area
(It does not flow into the sewage treatment plant)Hydrogen ion concentration PH5 or higher 9 or less HP5.8 or higher 8.6 or less Suspended Substances
Bentonite
Other earth and sand6000 ppm or less 70 ppm or less - If the pipeline is blocked or damaged due to effluent such as construction drainage, restoration work costs for the facility will be collected. However, if there is an application for self-financing construction from the cause, the cause person to carry out restoration work.
- Please apply for permission and notification procedures as follows.
Permit application and notification procedures Application documents Number of copies Date of submission Submission address Public sewer temporary use permission application 3 copies 14 days prior to release Public Works Office registration form digs near public sewers 2nd section 7 days before dug Public Works Office
For inquiries to this page
Asahi Ward Asahi Public Works Office
Phone: 045-953-8801
Phone: 045-953-8801
Fax: 045-952-1518
Email address: do-asahiiken@city.yokohama.jp
Page ID: 708-080-511
