BioDisc Sewage Treatment Plant FAQs
What size BioDisc do I need?
Refer to the British Water guidance for treatment plant sizing.Top
What is the BOD Quality?
Biochemical Oxygen Demand, simply described as a measurement of the strength of the effluent. Calculated by determining the difference in the dissolved oxygen (DO) content of the effluent before and after a 5 day incubation period. The greater the difference, the more organic material within the sample, as more of the DO has been absorbed as the material breaks down. Therefore the poorer the quality of the sample.
Top
Do I need consent from local authorities?
All discharges from Septic tanks and Treatment Plant require approval from the environment Agency and in most cases, the installation of the equipment will need approval of Building control.Top
What type of electrical supply do I need to the unit?
All small domestic plant generally require a single phase 240v power supply. Larger plant are normally specified with 3 phase 415v power supply requirements.Top
Can I drink the discharge from the unit or use it to irrigate my garden?
Drinking of the effluent is unwise and not recommended. Irrigation of gardens is permissible if the effluent is delivered via sub surface systems. It is unwise to spray treated effluent by sprinkler delivery systems as there are still contaminants within the effluent that may present both an ‘aerosol hazard’ and also may come into contact with children and pets playing on lawns etc.
Top
What is the flow rate from my unit?
The average flow rate may be calculated by establishing the number of residents, allowing 200ltrs/day/person and then dividing this figure by 1440. This will provide a l/min flow rate.
Top
Can I use a waste disposal unit and water softeners with this unit?
Waste Disposal units are not recommended as they are generally abused and can often allow an excessive load to be applied to the plant. Water softeners in themselves do not present a problem however, it is better to route the waste (spent regenerant) from the softener to a separate soakaway.Top
Does this unit need emptying and if so how often?
All treatment plant do require emptying. The frequency is dependant on usage and capacity. Most small domestic plant require emptying every 6 to 12 months on average.Top
How much land drainage do I need if im using a soak away?
Soakaway size is dependant on the results of the porosity or percolation test and amount of flow.
Top
What type of power cable do I need for the BioDisc?
Power supply cable should be an SWA (Steel Wire Armoured) cable. The number of cores would be 3 for single phase and 5 for 3 phase. The cable size is dependant on the size of the equipment (current demand in amps) and the distance between the supply point and the equipment.
Top
Can I have a BioDisc installed in a holiday home where it will have very infrequent use?
Yes however, during extended periods if non use, the biomass will start to reduce as will the potential treatment ability of the system. When additional load is reapplied, this will again re-establish but under this type of loading criteria, the plant wil probably never reach it’s full process potential
Top
How far away does the BioDisc need to be situated from a dwelling?
Minimum of 7.0m from any habitable parts of the building.Top
Can this unit deal with surface water?
No, Package Sewage treatment plant are not designed for combined foul and surface/storm drainage.
Top
Can I use a BioDisc if I have a high water table?
Yes, the plant may need to be specified with a pumped discharge and the installation of the plant should be completed with a concrete backfill and in accordance with the installation guidelines.Top
Can I use all my usual cleaning products?
Generally most cleaning products may be used so long as the proportions re not excessive and products that contain chlorine and biological Soap powders should be avoided. The more cleaning chemicals used, the harder it is for the naturally occurring bacteria to establish a working biomass.Top
Where do I drill the hole for the power supply cable?
This should be 18” below finished ground level and the hole in the GRP casing should be sealed with either a grommet or gland to avoid the ingress of ground water.Top
I have access to a watercourse but I cant get a gravity feed into it, is there anything I can do?
In this situation, we would normally advise the use of either a pumped discharge plant with an integral pump within the plant, commonly available on small domestic units or by the use of a pump station into which the plant discharges to by gravity and that the pumped discharge is delivered to the discharge point. Pumped discharges incorporate a non return valve which prevents water from the watercourse running into the plant.Top
Can the BioDisc be sited in a trafficked area?
The covers of the Biodisc are not rated for pedestrian loading, as such the plant should not be sited in area’s that are subject to any traffic whatsoever.Top
How long before my treatment plant starts to work properly?
All treatment plant require a start up period. This can be anything up to 6 weeks but there are a number of factors that may influence this. Namely the amount of load applied, the extent of chemical usage and whether the media is seeded with freeze dried bacteria, which often reduces this period by anything up to 50%Top