The Microbiology of Permeable Pavements

SUMMARY Pervious pavement systems (meaning permeable pavements within this context and used interchangeably) are known to retain and degrade hydrocarbons within the structure of the pavement. The key to this decontamination has been shown to be the naturally occurring microbial communities living on the pavement building materials. Research by Formpave and Coventry University has shown that once oil is trapped on a suitable strongly oil-retaining geotextile membrane layer, the oil rapidly becomes a food source for the microbial communities. Oil is metabolised by aerobic bacteria and fungi that convert the oil into sugars such as glucose for growth and reproduction. Over time, a network of microbial growth spreads over the surface of Inbitex forming a biofilm, further improving the filtration and purification properties of the system. The presence of a large food source growing on the oil attracts larger predatory organisms such as protozoa and metazoa to the biofilm. These organisms play an important role in maintaining the free-draining characteristics of the geotextile and also the vigorous growth of the oil degrading organisms. An understanding of the processes underpinning the environmental benefits of permeable pavements is essential in order to optimise the operation of the system