Excavation and temporary use near public sewers

1. When we perform the following drainage such as construction drainage and use public sewer temporarily, please submit public sewer temporary use permission application, and please receive permission of Mayor Public Works Office. （Yokohama City Sewerage Ordinance, Article 17, Paragraph 3）
   • （１） Spring water, rainwater, and construction drainage associated with civil engineering and construction work.
     (For spring water and rainwater, when using a pump with a kettle area)
   • （２） Drainage from temporary toilets and hand-washing areas installed in temporary offices
   • （３） Accumulated water from caretaker holes for telegraph telephone, electricity, gas, etc.
   • （４） Sewage drainage associated with other construction work.

   In addition, when applying, the drainage method etc. must conform to the attached standards. In addition, waste equivalent to industrial waste cannot be drained.

2. When digging near the public sewer for civil engineering or construction work, if you are going to dig deeper than the drainage pipe, please submit the registration form near the public sewer. （Article 25 of the Yokohama City Sewerage Ordinance）
3. Drainage method
   • （１） When discharging in a combined area, it flows directly into the connecting basin.
   • （２） When discharging in a diverted area, let it flow directly into the sewage connection basin.
   • （３） Drainage associated with construction on the road (including underground) can be connected to the human hole by laying the mounting pipe and flow in. However, please consult with Public Works Office about connection position, construction method, restoration method, etc.
   • （４） If there is no connection basin on or near the site, apply for self-financing at Public Works Office and install the connection basin and mounting pipe, and submit an application for temporary use.
4. Structure of drainage facilities, etc.
   When draining construction drainage, etc., install drainage facilities as follows. (Excluding Temporary Office Miscellaneous Drainage and Temporary Toilet Drainage)
   • （１） Public sewerage facilities, road facilities, etc. that do not interfere with traffic.
   • （２） In the drainage facility, install a sedimentation tank that meets the following criteria.
     Oh, rectification board, cough, etc. shall be provided to make a shape that does not cause disturbance by running water.
     B. The sedimentation tank has two or more tanks
     C. In principle, the average flow velocity is 0.3 m/s or less.
     D. In principle, stay time is 30 seconds or more.
     (E) The mud is 60cm or more.
   • （３） When discharging alkaline or acidic sewage, set up a neutralization tank and adjust it before releasing it. In principle, the neutralization tank must have a function to automatically stop the power pump when the water quality exceeds the standard value.
   • （４） In principle, the sedimentation tank shall have a structure that can measure the flow rate.
5. Certification of water quality standards and amount of wastewater
   • （１） In addition to those listed in the following table, the water quality of drainage for construction is based on the ordinances related to the conservation of the Yokohama City Living Environment and the Yokohama City Sewerage Ordinance. Water quality should be inspected at any time, and appropriate management should be performed to comply with legal standards.

     Certification of water quality standards and amount of wastewater

     Items	Treatment area (Inflow into the sewage treatment plant)	Unprocessed area (Not inflow into sewage treatment plants)
     Hydrogen ion concentration	PH5 or less than 9	HP 5.8 or higher 8.6 or less
     Suspended substances Bentonite Other earth and sand, etc.	Less than 600 ppm	70ppm or less

   • （２） Authorization of drainage and adjustment of sewerage usage fee is performed by Environmental Planning Bureau Accounting Division sewerage usage fee charge (telephone 671-2826). Please pay the sewerage fee by delivery letter of advice issued by Motoichi.
   • （３） If you violate laws and regulations or the above-mentioned standards and permission conditions, or if the city deems it necessary, you may rebuild, relocate or remove drainage facilities. In this case, the cost will be borne by applicant.
6. 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 work from the causal person, the causal person must carry out the restoration work.
7. Please apply for permission and notification procedures as follows.

   About permission application and procedure

   Application documents	Number of copies	Date of submission	Submission address
   Public sewer temporary use permission application	3 copies	7 days before release	Public Works Office
   registration form, near the public sewer	2 copies	7 days before drilling	Public Works Office

8. Contact information, etc.

   Contact list

   Contact information	Phone number	Contents of inquiry
   Environmental Planning Bureau Accounting Division Sewer Fee	671-2826	Report on the amount of wastewater, inquiries about sewerage usage fees
   Environmental Planning Bureau Sewer Management Division Sewer Management	671-2842	View the application form and sewer ledger map attached to registration form
   Environmental Planning Bureau Water and Soil Environment Division	671-2489	Water quality standards for public water bodies
   Resources and Waste Recycling Bureau Industrial Waste Management Section	671-2513	Industrial waste
   Public Works Office in the district where the site is located	Please check the link.	Inquiries other than the above

(Reference)　Yokohama City Sewerage Ordinance

• Article 17, Paragraph 3
  (Notification of start of use, etc.)
  Regardless of the provisions of the preceding two paragraphs, those who intend to use the public sewer by eliminating sewage associated with civil engineering, construction work, etc., and those who intend to temporarily use the public sewer must obtain the permission of the mayor in advance. Must.
• Article 25
  (dig near the public sewer system)
  Person who is going to perform construction to dig deeper than burial position of the drainage sewer near drainage pipe culvert of public sewer must notify the mayor beforehand according to rule.
  2 The mayor may order the person who performs the construction set forth in the preceding paragraph to the extent necessary to maintain the function and structure of drainage pipes in public sewers.