Septic tanks for the partial treatment of wastewater

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Discover the simplest way to protect your property and the environment with our range of compact Rewatec septic tanks.

Premier Tech range of Rewatec septic tanks

What is a septic tank?

A septic tank is an underground system that receives and partially treats raw wastewater from domestic or commercial properties not connected to municipal sewers. They are typically the most economical form of wastewater treatment.

CALONA Rewatec septic tanks

With nominal capacities from 3,000 up to 250,000 litres, our Rewatec septic tanks (formally Conder septic tanks) are ideal for virtually any application. Quick to install, simple to use, and easy to maintain, these durable solutions give you a discreet and reliable performance you can trust.

Our septic tanks are also CE and UKCA marked having been fully tested and certified to EN12566-1.

Properties owners, please note: as per the building regulations, a standard septic tank that discharges to surface water, no longer complies with UK regulations (2020 General Binding Rules). However, our septic tanks are still extremely popular and can be installed as part of a larger sewage treatment system (for example with our Ecoflo wastewater treatment system for energy free wastewater treatment).

Example applications

  • primary residences
  • seasonal residences
  • residential developments
  • apartment buildings
  • campsites and parks
  • office buildings
  • commercial sites
  • schools

How do our septic tanks work?

CALONA millenium stockage

Primary treatment

Wastewater from the property runs into a main drainage pipe that flows into the septic tank. The septic tank’s job is simple: it allows wastewater to separate into three layers.

In the top layer, oils, greases, and fats float to the surface and form scum. In the bottom layer, solids settle on the bottom of the tank and form sludge. Periodic emptying by a licenced waste disposal company is required to remove the gradual build-up of scum and sludge.

Partially clarified liquids accumulate between the layers of scum and sludge and exit the septic system through the outlet pipe. An integrated effluent filter - standard in all 3,000-10,000 litre polyethylene Rewatec septic tanks, capture suspended solids that could clog system components further downstream.

Wastewater final dispersal

As the effluent is not fully treated, wastewater can flow into an advanced secondary system for additional treatment (Ecoflo, MBBR, or SBR) to meet the the general binding rules set out by the Environment Agency and to fully protect our environment. 

Septic tank maintenance

Protect your investment in your Rewatec septic tank by having it regularly inspected and desludged by a qualified service professional.

The frequency of service depends on the size of your tank, the amount of wastewater your property generates, and the environmental regulations in your area. It is best to speak with a local service professional to determine the service schedule that is right for you.

When your service provider visits your property to inspect your system, they should:


  • check for cracks and leaks in the tank
  • measure the scum and sludge layers
  • desludge the septic tank as required
  • clean the effluent filter in the outlet pipe
  • keep and update maintenance records for your system
  • explain any areas of concern and recommend next steps


Our septic tank warranty 

For over 50 years, we have proudly developed sustainable and long-lasting products that make a real difference for our customers, our professional partners, and, above all, our planet.

Our experience in the industry allows us to give you a complete warranty for septic systems.

Our Rewatec septic tank warranty includes:

  • 10 year shell and construction (polyethylene)
  • 25 year shell and construction (GRP)


Training programmes

At Premier Tech we provide a full range of training programmes to fully meet the requirements of our professional partners. If you require product functionality guidance or a more detailed training course for installations, for example: is a concrete or a granular surround suitable for the septic tank you have purchased, we can provide a solution to meet your needs.

Contact us for more information 

Available products

We offer a complete range of septic tanks to meet your needs from 3,000 litres to 250,000 litres. Wherever your site, whatever the regulations, we have the right product to transform any wastewater treatment challenge into a tailor-made solution.

Free quote

We are here to help. Request a quote today and our team of experts will be in touch. 

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