Permeable pavements: Pollution management tools

The latest tests on permeable road surfacing demonstrate the rate at which clogging occurs, according to the type of surface, and the best methods for recovering micro-pollutants. In the first year there is little change in underseepage rate but thereafter decline is rapid, reaching 50% of the original rate after 2 or 3 years. For highly permeable surfacing containing many spaces, absorption capacity remains high even after this period, but methods of preventive maintenance, such as suction, need to be used in order to avoid the use of even more costly methods, such as high pressure water jet with simultaneous suction. However, permeable surfacing does enable the storage and recovery of most micro-pollutants, thus preventing such particles being washed off into the ground.