Installation guide

9
Installation
INTRODUCTION
Installation procedures must be in accordance with the Safety, Health And Welfare at Work Act 2005, and other relevant legislation.
Your procedures must also align with good building practice.
This procedure is issued as a guide only. EPS Bison accept no liability for incorrectly installed units. If the customer has any concerns
then a suitably qualified groundworker who has full access to all site conditions should be consulted.
During installation it is important to check that the treatment plant remains level across all planes. The performance
of a mis-aligned unit may be affected.
Note:
Installing in an excavation that allows water to enter (i.e. not dry) requires special advice. High water table or flood conditions will
cause problems during installation. They may also affect the desludging of the plant; again specialist advise must be taken in these
conditions. Backfill around tank with 20N concrete to within 200mm of ground level.
The Bison ASP is installed at the required level so as to connect the sewer discharge from the dwelling. Where appropriate, the neck
of the top section may be trimmed to suit ground topography at the commissioning stage.
Care should be taken to ensure that no large stones, etc are allowed into the excavation during back-filling.
The base of the excavation should be adequately filled with stone and sand and adequately compacted so as to ensure that no
lagging or subsidence occurs once the unit is in operation.
A concrete flagstone may be used at the base as appropriate (450mm x 450mm x 35mm).
INSTALLATION PROCEDURE
Step 1
Excavate a 2,500mm² hole, distance C (ref. Pg 7) below the invert of the sewer discharge from the dwelling.
Step 2
The base of the excavated hole must be firm, undisturbed soil.
Place some sand and stone and compact well to ensure firm bedding for the system.
Step 3
Lift the system into the hole utilising the lifting bolts provided.
Ensure that the tank is empty when lifting at all times.
Step 4
Check that the sewer connections are aligned correctly and that the tank is sitting properly in the hole.
Make the connections and level the tank utilising the marked neck as provided.
Step 5
Once satisfied that the tank is level, etc, backfill to a depth of 750mm with the appropriate backfill.
At this stage the tank should have stabilised. Recheck that it is still level, if not relevel the tank.
Step 6
At this stage start filling the tank with water up to the outlet weir provided.
At the same time continue to backfill the excavation up to ground level with the appropriate backfill.
Step 7
Leave the tank full of water to the TWL, i.e. at the outlet weir.
Replace the top cover on the tank and leave 2m of cable spare at the neck of the unit for commissioning the system at a later stage.
Step 8
It is important that the cover of the tank is above ground level and will always remain over ground level.
Note:
Ensure that adequate ventilation as per regulations is provided.