Filling Station Forecourt Separators

Protecting water courses from spillages

The EA and SEPA Pollution Prevention Guidelines (PPG) which are jointly produced by the Environment Agency for England and Wales, the Scottish Environment Protection Agency, and the Environment and Heritage Service for Northern Ireland (Ref PPG3 / PPG13 / PPG4 / PPG 14) suggest that Class 2 wash bay silt traps and interceptors should be connected only to a mains foul drain, and Class 1 separators to surface drain.

The above assumes you have the consent to connect any outflow to a suitable drain as per the appropriate PPG Guideline. While we always endeavour to provide best advice and accurate information, it the responsibility of the client and/or landowner to comply with the law. Following any guideline doesn’t remove your responsibility to comply with the law and prevent pollution from your activities. Causing or allowing pollution is a criminal offence; compliance with any guidance isn’t a defence. You should make sure that the references to other sources of guidance are still current.

Forecourt separators

This page uses the term forecourt to refer to all forms of liquid-fuel dispensing outlets, both retail and non-retail, including those where only diesel is dispensed.

A forecourt separator must be a 'full retention' separator, large enough to serve the catchment area of the site and have a sufficient oil storage volume to retain any foreseeable spillages.

It is important to install a forecourt separator of an appropriate size. On a forecourt where tanker deliveries are received, a separator with an oil storage capacity of 7,600 litres will meet the requirements of BS EN 858-2, clause 4.3.6.

If a smaller unit is proposed, the size should be determined by undertaking a risk assessment incorporating catchment size, potential spillages during delivery, and other risks such as safety issues. If the compartment size of the tanker that delivers to your site is greater that 7,600 litres your separator should be sized accordingly.