Petrol Seperators
Full Rention Seperators
Full retention separators treat the full flow that can be delivered by the drainage system, which is normally equivalent to the flow generated by a rainfall intensity of 65mm/hr.
On large sites, some short term flooding may be an acceptable means of limiting the flow rate and hence the size of full retention systems.
Forecourt Seperators
Forecourt separators are full retention separators specified to retain on site the maximum spillage likely to occur on a petrol filling station. They are required for both safety and environmental reasons and will treat spillages occurring during vehicle refuelling and road tanker delivery.
The size of the separator is increased in order to retain the possible loss of the contents of one compartment of a road tanker, which may be up to 7,600 litres.
Bypass Seperators
Bypass separators fully treat all flows generated by rainfall rates of up to 6.5mm/ hr. This covers over 99% of all rainfall events. Flows above this rate are allowed to bypass the separator.
These separators are used when it is considered an acceptable risk not to provide full treatment for high flows, for example where the risk of a large spillage and heavy rainfall occurring at the same time is small.
