Full retention separators 

Registered white Rewatec logo.

Guard against hydrocarbon pollutants entering the environment, even during storm surges, with our robust and reliable full retention separators. 

Rewatec full retention separator

What are full retention separators?

Full retention separators, sometimes known as petrol interceptors, 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. 

Full retention separator maintenance

We have a network of local service partners to maximise the life of your Rewatec full retention separator and to provide years of reliable operation.

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

Training for professionals

​​​​​​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, we can provide a solution to meet your needs. 

Contact us for more information

Available products

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


Free quote

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

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