A. INSTALLATION GUIDE 4. INSTALLATION OF THE SYSTEM
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Installation and User guide – MONOBLOCK Systems – 06-12-2016
4.2.3 Backfilling in dry ground conditions
Backfill the hole with 3 to 6 mm smooth pea gravel, or lean-mix concrete whilst filling the
tanks with water at the same level
Do not exceed 300 mm per water filling and compaction cycle
Backfilling around and filling both the Primary Tank and BIOROCK unit with water should
take place at the same time.
Make sure that the BIOROCK media is completely saturated with water
Do not backfill with the soil removed during the excavation: roots and stones can damage
the tank.
Do not compact the backfill material mechanically: compact manually.
Once the backfilling is finished and compacted, check the levels of the tanks again
The lids or access covers of the system should be installed just above ground, level to
provide easy access for maintenance.
Close and secure all covers with screws
Complete the backfilling once all pipework has been checked and connected.
4.3 INSTALLATION IN HIGH GROUND WATER CONDITIONS
Appendix 1.2
«Installation in high ground water conditions»
Conditions for installation:
L
Wet ground
L
Presence of high ground water table etc.
The MONOBLOCK units can be installed in high ground water conditions with special
precautions.
The level of the water table must never exceed the level of liquid inside the Primary
Compartment. Extremely high water tables signify a flood risk which could cause
water ingress or collapsed tanks.
Perform the same work as in dry ground conditions with the additional recommendations and
modifications below:
For installations in a high water table area, ensure the adequate drainage of the excavation during
installation
Anchor the unit to the concrete slab (slab thickness should be a minimum 200 mm)
The base must extend to a minimum distance of 300 mm beyond the base of the tanks on all sides
If you are unsure, a qualified civil engineer should be consulted
Anchoring the tanks to the base is achieved with a system using the anchoring points; these
are positioned at the bottom of the tank.
Lateral backfilling is 300 mm thick around the system and consists of sand/cement lean mix
concrete (dosing: 200 kg cement / m³.)
For installations in a high water table area, ensure the adequate drainage of the
excavation during installation and anchor the unit to the concrete slab
