Johkasou - Installation

OUTLINE• Legal frame work of Johkasou installation• Johkasou installation works

Legal Framework for Johkasou Installation
The following items are listed in the Johkasou Act with regard to installation
Notification
Submit a notification of Johkasou installation to the competent authorities
prior to construction

Installation- Construction can only be performed by a business office registered in
the prefecture that has jurisdiction over the area where the installation
work is to be performed- Installation or supervision by a national qualified Johkasou installer3

Johkasou Installation Flow4１

Prior On-Site Survey

Check installation location and delivery route２

Application for installation Submit notification of Johkasou installation

３

Temporay work

Site preparation

4

Excavation

Excavate to required depth

5Foundation

Make a reinforced concrete slab

6

Installation

Install Johkasou on the base slab

7

Filling water

Fill the Johkasou with water8

Backfilling

Backfill around Johkasou with sand9

Piping work

Connect each piping

10

Electrical work

Install blower, pump, control panel and so on

11Upper conclete work

Make a RC slab on Johkasou

12

Trial operation

Check Johkasou and equipment function

13Cleaning & Handover

Explain Johkasou to users

Johkasou Installation - Prior On-Site Survey
PurposeTo check the site conditions prior to Johkasou installationand ensure smooth installation

Check Point
Sufficient area to install a Johkasou
Location and depth of inlet pipe
Treated water discharge point
Existing pipe and cable location
Ground water level
Special installation or not
Johkasou delivery route
Electricity and tap water availability
Blower and control panel location
Maintenance workability

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Johkasou Installation – Application for Installation 6Purpose

Ensure that Johkasou is properly install
Ensure Johkasou model, capacity, install date and builder

Documents
Notification of installation of a Johkasou
Notification of change of Johkasou
Johkasou card
Johkasou use start-up reportJohkasou owner change report
Notification of discontinued use of Johkasou
Notification of Johkasou out of use
Notification of Johkasou re-use start-up
Technical operator change reporthttps://www.kankyo.metro.tokyo.lg.jp/resource/general_waste/septic_tank/septic_tank_law.html

Johkasou Installation – Temporay work
Purpose

Prepare site for excavation can be done without problems
Measure and determine the area to be excavatedDescription
Clearing the ground before installation
Decide where to install Johkasou
External inspection of the Johkasou

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Johkasou Installation – Excavation
PurposeFor underground installation, excavate as per the drawing
Underground installation allows for effective use of space

Description
Excavate to the depth required in drawing
Use retaining walls if necessary
Use submersible pump if groundwater spring

Point
Excavate about 5 cm larger than the size ofthe bottom slab to make it easier to work on8

Johkasou Installation – Foundation 1
Purpose Use rubble stones to harden the foundationDescription
Make sure it has the necessary square footage
Place rubble stones of unequal size
Fill in the gaps with sand
Stamp them sufficiently with a rammer

PointThickness shall be in accordance to drawing
Usually 100 mm or 150 mm (T-0)

9Johkasou Installation – Foundation 2Purpose

To install Johkasou horizontally
Prevent Johkasou from being raised by groundwater

Description
Place concrete 50mm thick on the rubble stone according to the drawing
Make a temporary framework with the specific dimensions
Rebar arrangement according to the drawings
Install anchors according to the drawingCast concrete with surface tolerance of ±2.5mm/1m

10Johkasou Installation – Installation
Purpose Install Johkasou on base slab

Description
Visual inspection of Johkasou
Clean base slab (small stones, etc.)
Lift Johkasou according to the manual
Place Johkasou in the center of base slab
Check Johkasou is installed horizontally
Install wire to prevent raising by groundwater11

Johkasou Installation – Filling Water
PurposeTo protect Johkasou from soil pressure
To prevent the Johkasou from shifting during backfilling

Description
Check Johkasou is secured with wires
Fill Johkasou with tap water
Make sure Johkasou is not leaking water12

Johkasou Installation – Backfilling
PurposeProtects Johkasou from UV light
Fill in gaps for easier maintenance
Description
Ensure Johkasou is filled with water
Ensure backfill sand is free of stones and gravel
Cover Johkasou to prevent sand from getting inBackfill and water tightening in three steps

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Johkasou Installation – Piping Work
PurposeConnect inflow pipe, effluent pipe
Connect blower and Johkasou

Description
Connect the inflow pipe and Johkasou
Connect the effluent pipe and Johkasou
Connect the blower and Johkasou with piping
Air pipes shall be 10m in length and within 5 bends
Install an exhaust pipe for surrounding area
Install pipe supports if necessary
Point
Be careful not to allow sand to enter the piping
Check drawings for piping sizes and install14

Johkasou Installation – Electrical work
Purpose Install blower, pump, control panels…
Description
Install a blower in a well-ventilated place
Avoid direct sunlight on the blower
Blower should be installed on flat concrete
Provide grounding works as required

Point
Air piping should be kept as sand-free as possible
The platform for the blower should be about 200mm higher than the GL.
Use header pipes if there is more than one blower

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Johkasou Installation – Upper Concrete WorkPurpose

To prevent rainwater from entering the tank
For easier maintenance works

Description
Cast upper slab in same procedure as base slab
Note that the reinforcement is different from the base slab

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Johkasou Installation – Trial Operation
Purpose Check for proper operation through a trial operation
Description
Check piping joint condition
Check for air leakage
Check if moving bed medias are moving well
Check there is no difference in water level
Check if the circulation volume can be set17

Johkasou Installation – Cleaning & HandoverPurposeClean around Johkasou andHand over the Johkasou to its user

Description
Clean up sand and trash
Report to the user that the construction has been completed
Inform users about proper use of Johkasou and precautions to be taken

18Johkasou Installation Reference
Underground installation
Half underground installation

Above ground installation

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References of Special Installation
Under ground installation

Special installation

Inlet pipe position is lower

Load carrying capacity

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Features of Johkasou Installation

Above ground

Under ground

Short construction periodEasy maintenance

Save the cost of construction

Utilization of space

Possible to relocate in thefuture

Ultraviolet no effectWe can chose some installation due to the site condition.

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