• Print page
  • Bookmark
  • Email page

BioDisc® BA-BD

High Performance Package Sewage Treatment Plants
for Residential Applications

BioDisc® BA-BD

For domestic dwellings without access to mains drainage, the Klargester BioDisc® provides a reliable, efficient and environmentally safe solution to your sewage disposal needs.

It is ideal for locations where discharge is to sub-surface irrigation, or to a suitable watercourse where approved by the Regulator, and where a septic tank will not meet the required standards.

Certified to European Standard EN 12566
- Part 3 - Annexe B - Performance Tests

In 2005, the Klargester BioDisc® underwent 40 weeks of stringent testing to assess its treatment efficiency as part of Klargester's commitment to meet the new European Standard for small treatment plants.

After delivering exceptionally high levels of pollution removal (95%) under varying loads and conditions, the Klargester BioDisc® was awarded its Performance Certificate. The test report also highlighted:

  • The Klargester BioDisc® operates without noise or odour
  • Maintenance requirements are low with good access
  • No technical or mechanical faults
  • Low power consumption at 1.3kw/d - approx 10-14 pence per day*
  • Low sludge build up and large storage capacity

Unique Design

Unique Design

The Klargester BioDisc® is the only packaged sewage treatment plant utilising Rotating Biological Contactor technology for small domestic applications. This process offers inherent cost and performance benefits with a low carbon footprint.

Assured Performance

Klargester BioDisc® is a high performance package treatment plant which, in normal domestic situations, will produce effluent qualities of better than 8mg/l BOD, 13mg/l SS and 4mg/l ammonia.

Low Running Costs

low running costs

Klargester BioDisc® has the lowest running and maintenance costs of any packaged treatment plant in its class. The single home unit requires an annual de-sludge only, the motor rating is 50 watts and routine mechanical maintenance is minimal.

Low Lifetime Costs

Lowest running costs combined with the quality and durability of the equipment - particularly the drive motor which has a considerably longer service life than the pumps and blowers fitted to competitive units - all add up to a significantly lower lifetime cost for the Klargester BioDisc®.

Process Stability

process stability

The Klargester BioDisc® is recognised for its process performance. This is further enhanced by Klargesterl’s unique Managed Flow System, which ensures optimum performance by smoothing peak flows and buffering biological loads over the whole working day.


Low Profile Covers

low profile covers

Access for service and maintenance is provided via a durable, unobtrusive cover at ground level.



Subject to relevant authorities consent and site conditions, the plant discharge can be a watercourse or to a drainage field.

Standard Invert Options

Three standard drain invert level options are available from stock to match the site topography and where applicable, minimise the excavation depth. The Klargester BA, and BB BioDisc® are available with an integral pump to move effluent from point of treatment if site level demands.

Nationwide Availability

Klargester products can be sourced from your local builders merchant or through local pollution control specialists.

How the Klargester BioDisc® Works

Central to the operation of each Klargester BioDisc® is the Rotating Biological Contactor (RBC), which supports a biologically active film or biomass on to which aerobic micro-organisms, naturally found in sewage, become established. Natural breakdown of sewage can then occur as described below.

BioDisc® BA-BD

The Breakdown Process

Wastewater and sewage flows into the primary settlement zone(1) where solids are settled out and retained. This accumulated sludge should be drawn out periodically.

Partially clarified liquor containing fine suspended solids flows upwards into the first stage Biozone (2) for breaking down by micro-organisms on the RBC. Suspended solids return to the primary settlement zone and the liquor is transferred to the second stage Biozone (3) for further treatment.

Any solids remaining are settled out in the final settlement tank (4). The very high effluent quality is discharged to a watercourse.

The RBC comprises banks of vacuum formed polypropylene media supported by a steel shaft. This is slowly rotated by a low energy consumption electric motor and drive assembly.

Note: The Klargester BioDisc® is designed to deal with normal domestic sewage. If the sewage is likely to contain unusual substances, please consult Klargester.


Unit Size Single House
Population Equivalent 1 house,
up to 4 bedrooms
1 house
up to 7 bedrooms
Overall Diameter / Width (A) mm 1995 1995
Overall Length (B) mm - -
Standard Drain Invert Inlet (C) mm 750* 750*
Standard Outlet (D) mm 835 835
Depth from Invert to Base (E) mm 1400 1400
Pipework Diameter (mm) 110 110
Sludge Storage Period (approx) 12 months 9 months
Standard Power Supply Single phase Single phase
Motor Rating 50W 50W
Weight (tonnes) standard units 0.388 0.418
Unit Size Multiple Houses
Population Equivalent 2 houses
up to 8 bedrooms
3 houses
up to 12 bedrooms
4 houses
15-16 bedrooms
Overall Diameter / Width (A) mm 1995 2450 2450
Overall Length (B) mm - - 3340
Standard Drain Invert Inlet (C) mm 750* 600** 600**
Standard Outlet (D) mm 835 685 685
Depth from Invert to Base (E) mm 1400 1820 1820
Pipework Diameter (mm) 110 110 110
Sludge Storage Period (approx) 6 months 7 months 6 months
Standard Power Supply Single phase Single phase Single phase
Motor Rating 50W 75W 75W
Weight (tonnes) standard units 0.418 0.650 1.100

Applications which include waste disposal units will require special sizing.
Please consult Klargester.
* Optional invert depths of 450mm and 1250mm are available.
** Optional invert depth of 1100mm is available.


Sizing Your Treatment Plant

The above table is a general guide to selecting the correct Klargester BioDisc® for your property but, with many variables to consider, it is essential to obtain an accurate assessment.

We are pleased to offer professional advice by adhering to British Water’s sizing criteria published in their guidance booklet ‘Flows and Loads’. By following this best-practice, Klargester will ensure you are installing the most suitable Klargester BioDisc® model to serve your needs.

Quick and Easy to Install

Supplied as a complete palletised unit with lifting and lowering fixings, the Klargester BioDisc® is ready for installation on a suitably prepared site. The unit should be stabilised in concrete and the back fill completed with concrete.

We can provide an installation service through our network of Approved Installers and full details are provided in our comprehensive installation instructions covering all site conditions. Additional technical information sheets are available on the Klargester BioDisc® process, siting, installation, effluent disposal and other specific topics. Please contact Klargester for further information.

Sample chambers

Sample Chambers

When a treatment plant discharges into a watercourse, it is a regulatory requirement to have a sampling point so that the effluent quality can be periodically checked by regulatory bodies.

Available to suit all outlet depths of our standard ranges, a Klargester sample chamber provides the solution, enabling both quick installation and easy access for accurate and convenient effluent testing.

Klargester Reed Beds

What is a Reed Bed?

A reed bed is a filtration process used in conjunction with a Klargester BioDisc® treatment plant to further enhance the quality of the effluent migrating into a drainage field or surrounding watercourse.

View More

Biodisc Installation

Case study

A treatment plant serving a 3-bedroom farmhouse

The client approached Kingspan Klargester to discuss the options for replacing a failing brick Septic Tank. Key criteria were to reduce frequency of tank-emptying visits and to use existing soakaway without the risk of blockage. Major concern was also to reduce pollution of surrounding streams and watercourses.

Contact us

Kingspan Klargester
College Road North
Aston Clinton, Aylesbury
HP22 5EW

Tel: 01296 633000
Fax: 01296 633001