Enhancement of oil retention and biodegradation in stormwater infiltration systems

This paper reports recent developments in oil trapping and oil biodegrading systems in pervious pavements and in infiltration systems used in conjunction with non-pervious surfaces. The advances made in the technology and operation of pervious surfaces fitted with an integrated oil water separator will be described. This involves a newly developed, floating mat system which serves to
interact with any oil which, in the event of a large spill, passes through the initial oil retaining structures of a pervious pavement or other form of infiltration system (see Puehmeier et al., 2004).
It also provides the ideal surface upon which the oil degrading organisms will thrive. The ability of these enhanced systems to produce a diverse biodegrading bacterial/fungal community is reported. A further study will report a comparison of biodegradation of new and used mineral oil trapped on these structures. The second area of research reported will be associated with a novel oil separating
system designed to be either coupled closely to an infiltrating filter trench which can be used in conjunction with impervious surfaces or to direct the water back under an impermeable surface for further treatment, retention and attenuation of flow. This system was shown to be highly effective in removing hydrocarbons and has the advantage that it can be used as a retrofit solution to allow disconnection of existing impervious surfaces without exposing groundwater to contamination.