High risk areas where large scale full retention is required.
Oil Separators
An Introduction to Separators
Oil separators can be fitted to surface water drainage systems to protect the environment from pollution by oils. They separate the oil from surface water and then safely retain the oil until it is removed.
Separators are installed to contain oil leaks from vehicle and plant and from accidental spillages.
To be effective, oil separators need to be correctly designed, installed and maintained.
Where are separators needed?
Surface water may be contaminated by oil in various types of location. These locations need to put measures in place to prevent this oil from contaminating the environment. Locations that may require separators include:
Car Parks
Areas where goods vehicles are parked or manouvered
Vehicle maintenance areas
Roads
Industrial sites where oil is stored or used
Refuelling facilities
Any other site with a risk of oil contamination
There are a variety of separators available for different types of application.
Bypass Separators
Bypass separators fully treat all flows, for the area served. Bypass separators are used when it is considered an acceptable risk not to provide full treatment for high flow, for example where the risk of spillage is low such as car parks.
Full Retention Separators
Full retention separators fully treat all flows, for the area served. The full flow is normally equivalent to the flow generated by a rainfall intensity of 6.5mm per hour.
Full retention separators can be used in areas, where there is a risk of regular contamination with oil and a foreseeable risk of significant spillages such as petrol stations etc.
In the event of a spillage, it is important to consider the flow rate of the liquid to the separator as the oil storage capacity needs to be sufficient to retain the entire spillage.
Forecourt Separators
A forecourt separator is used in outlets that dispense liquid fuel and/or diesel. 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 capacity to retain any foreseeable spillage’s.
It is important to install a forecourt separator of an appropriate size. For example where a tanker size of 7,600 litres or less delivering oil, a separator size 7600 litres will meet requirements of BS EN 858-2 clause 4.3.6.
