GL0016P-02 Installation Guidelines for BioDisc
®
Units BF, BG, NF & NG
5
3.4. If discharge is to a soakaway, a porosity test should be carried out in accordance with BS 6297 to
assist in assessing sub-soil drainage and designing the sub-surface irrigation system.
3.5. The BioDisc system must be installed at a level which will allow connection to the incoming drain and
a free discharge at the system outlet.
3.6. The unit should be installed so that the bottom lip of the cover is 65mm or more above local ground
level. If the unit has to be recessed, measures must be taken to ensure that it cannot be flooded by
surface water run-off.
3.7. There must be at least 1 metre of clear, level ground all around the unit to allow for routine servicing,
plus adequate space to allow complete removal of the covers.
3.8. The unit should be installed as far as possible from any habitable building. Many Local Authorities will
insist on a minimum distance of 15 metres.
3.9. Adequate access must be provided for routine de-sludging and maintenance, including crane access.
Vehicles should not be permitted within a distance equal to the depth of the unit, unless suitable
structural protection is provided to the installation.
3.10. BioDisc covers are not suitable for walking on. Where necessary the BioDisc should be fenced off or
otherwise protected. Maintenance access must be maintained as above.
3.11. An adequate electrical supply must be provided, complying with current electrical regulations. The
electrical details in Section 6.2.6. will enable selection of suitable cable and current overload
protection, taking into account the distance from the power source to the control panel and any other
relevant factors. In most cases steel wire armoured (S.W.A).cable, minimum 1.5sq mm will be
suitable, but this is a minimum recommendation and selection is the responsibility of the installing
electrician. Although not obligatory for an installation of this type, RCD protection is suggested as an
extra precaution.
3.12. Pump stations or any other associated equipment should have a separate power supply.
3.13. Proximity to a mains water hosepipe connection point is recommended, for maintenance purposes.
Such a supply should be connected in accordance with water bylaws and regulations.
Never leave a
hose connected and immersed in sewage.
3.14. Installation should only be carried out by suitably qualified and experienced contractors in accordance
with the Health and Safety at Work Act. Electrical work should be carried out by a qualified electrician,
working to the latest edition of IEE.
4.0 Installation - General
4.1. When units are installed in unstable ground conditions where movement of the surrounding material
and/or unit may occur, the connecting pipework should be designed to minimise the risk of damage
from differential movement of the unit(s) and/or surrounding material.
4.2. In situations where the excavation will not maintain a vertical wall, it will be necessary to support side
walls of the excavation (eg. with suitable trench sheets and bracing systems) to maintain a vertical wall
from the bottom to the top of the excavation. DO NOT completely remove the shoring system until after
the backfilling is complete, but before the concrete fully hardens.
4.3. In areas where the water table is above the bottom of the excavation and/or the excavation is liable to
flood, the excavation should be de-watered, using suitable pumping equipment, until the installation is
complete. In such conditions it may be advisable to line the excavation with polythene sheeting, to
prevent cement being washed out of the concrete surround/base.
4.4. During installation care must be taken to ensure that the body of any unit is uniformly supported so
that point loads through the unit are avoided.
4.5. A water supply must be available on site to enable the unit to be ballasted during backfilling.
4.6. Concrete
Specification
is a general specification. It is not a site specific installation design.
