Full retention separators

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Guard against hydrocarbon pollutants entering the environment with our peace-of-mind full retention separators.

Rewatec Full Retention Separator

What are full retention separators?

Full retention separators are used where there is a risk of regular oil contamination and a foreseeable risk of significant over spills. They are designed to treat the full flow that can be delivered by a drainage system. This is normally generated by rainfall intensity of 65mm per hour, often referred to as ‘torrential’.

Example applications

  • sites with high risk of oil contamination
  • fuel storage depots
  • refuelling facilities
  • vehicle maintenance areas/workshops
  • where discharge is to a sensitive environment


Rewatec full retention separator

If it is considered to be an acceptable risk not to provide full treatment for high flows, visit our bypass separator page for a solution that meets your needs.

How do full retention separators work?

Step 1

Contaminated water enters the separator where the liquid is retained for a sufficient period to ensure that the pollutants (such as petrol, diesel or oil) separate and rise to the surface of the water.

Step 2

The decontaminated water then passes though the coalescing filter before it is safely discharged from the separator, with the remaining pollutants being retained inside the separator.

Step 3

Retained pollutants must be emptied from the separator once the level of oil is reached, or the oil level alarm is activated. This waste should be removed from the separator under the terms of the Waste Management Code of Practice.


Rewatec full retention separator operation


All Rewatec full retention separators have an automatic closure device (ACD) fitted as standard. This is compulsory for all compliant full retention separators and prevents accumulated pollutants flowing through the unit when the maximum storage level is reached.

If it is considered to be an acceptable risk not to provide full treatment for high flows, visit our bypass separator page for a solution that meets your needs.

Full retention separator maintenance

We can provide a range of services to maximise the life of your Rewatec full retention separator and to provide years of reliable operation.

Contact us to find out more

We stand by our products

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 25 year warranty for Rewatec full retention separators.

Rewatec 25 years warranty

Visit our office

​​​​​​At Premier Tech we strive to fully meet the requirements of our professional partners. If you require product functionality guidance or more detailed information for installations, we can provide a solution to meet your needs.

Contact us to find out more

Technical information

Our Rewatec full retention separators can be installed for drainage areas ranging from 222m2 to 47,222m2.

Rewatec CNS full retention separator specification table


Here at Premier Tech, we understand that some sites require different pipework sizes to fit with the specific needs of the overall drainage system. If you have a requirement for larger or smaller pipework, contact us for a bespoke solution that meets your requirements.

Available products

Our Full retention separators are available in a range of sizes to suit all requirements.



Free quote

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