Performance Of an Oil Interceptor Incorporated into a Pervious Pavement

The use of pervious pavements is an important technique used for source control in sustainable drainage systems (SUDS) that allows water to infiltrate into hard surfaces and then slowly releases it to either a drainage outlet or into the ground. SUDS also remove low levels of pollution from the water by filtration and biodegradation of hydrocarbons that are adsorbed to materials within the construction. Current pervious pavement systems are not used in locations where the riskof pollution occurring is high or if they would allow the infiltration of water into the ground where groundwater protection is a concern. This paper describes trials of an oil interceptor that can be incorporated within pervious surface construction. The testing was undertaken to assess how the system retains pollution within it under simulated worst credible pollution and rainfall events. The results demonstrated that it can effectively contain hydrocarbon and metal pollution thus providing improved water quality. The water that flows out of the system has 50 times less oil pollution than the requirements specified for a Class 1 oil interceptor, when lubricating oil is applied to the surface. The water quality is over ten times better than the specified requirement when diesel is applied. Where detergents may be present they can cause minor contamination of the outflow waters and secondary treatment may be required.