Sewage Treatment Plants

What are septic tanks?

Septic Tanks are the old fashioned way of dealing with sewage. It stores solid waste and offers very little treatment to the liquid waste it accepts. A septic tank is often made from GRP or Polyethylene and it has a foul drainage pipe connected to the inlet and a drainage pipe connected to the outlet. From there it discharges into a soakaway or into a treatment plant where the effluent can be treated further. There are often two or three chambers inside the septic tank separated by dividing walls allowing the sewage to flow through.

How do Septic Tanks Work?

Sewage enters the primary chamber of the septic tank, where solids settle at the bottom via gravity. The settled solids are anaerobically treated reducing the overall volume within the tank. The liquid waste then flows through the dividing wall into the second chamber where further settlement takes place. The liquid is then discharged into a soakaway or if necessary, lifted to a sewage treatment system for further treatment before being discharged.
Waste will always remain in a septic tank despite the best efforts of anaerobic digestion as it offers very little treatment to settled sludge. The septic tank will eventually have to be emptied so as to prevent the sewage from overflowing into the drainage field (soakaway etc). This is not only very bad for the environment, but it will decrease the porosity of the soil and often clog up the soak way causing the raw sewage to back up and result in costly repairs being needed.

How often will I have to empty my septic tank?

This is determined purely by the volume of the tank in relation to the amount of solids going into it, the surface area contact and also the ambient temperature, as anaerobic treatment is more effective at a higher temperature. The emptying interval can vary greatly and often depends on usage, the diligence of the owner and also the different characteristics of each system. Some septic tanks need de-sludging every 4-6 months while others can go for over 12 months before requiring emptying. There is no set period of time determining how often a septic tank should be emptied.

Septic Tanks

The Bio-Pure Low Profile Septic Tanks feature a filtered outlet. The image shown is of the 3200 Litre Septic Tank.
**please note that the depth below invert is based on a traditional septic tank

3200 Litre (6 persons)

  • Height – 1300 mm
  • Length – 2230 mm
  • Width – 1400 mm
  • Depth below invert level – 1350 mm **

4800 Litre (12 persons)

  • Height – 1300 mm
  • Length – 3300 mm
  • width – 1400 mm
  • Depth below invert level – 1350 mm **

The Bio-Pure Low Profile Septic Tanks

As well as manufacturing, installing and servicing the Bio-Pure Sewage Treatment System, we also manufacture a Low Profile Septic Tanks with a filtered outlet.
This is designed to significantly reduce installation costs and increase effluent quality.
This is achieved by a larger service area contact which increases oxidisation, thus allowing the waste to broken down more efficiently than with a traditional onion shaped septic tank, resulting in majorly reduced pollution.
The Low Profile Septic Tank also features a filtered outlet which prevents any suspended solids from entering the soakaway. Also the Low Profile Septic Tank doesn’t require the same depth as a traditional onion shaped tank, so installation costs are lowered.

  • Fully designed and manufactured in accordance with BS EN12566-1
  • Concrete is only required for installation in a high water table or if a greater depth is required
  • We offer an adaptable invert level to cater for any individual needs
  • All risers and manholes are included
  • Typical emptying period of 12-18 months
  • 7-10 days lead time, but can be dispatched sooner if required

The Low Profile Septic Tank is available in 2 sizes and we can manufacture bespoke tanks if required. It can also be used as a “trash tank” to sit in front of a treatment system on a larger domestic, or commercial site.

To view our range of Septic tanks and Septic Tank Replacements please click the button below