The Benefits of Road Shallow Subbase Attenuation Layers

Road shallow subbase attenuation layers allow stormwater storage below the infrastructure in urban and suburban areas

Road shallow subbase attenuation layers allow surface water to gradually infiltrate into the subsoil when the subsoil is permeable enough or discharge to another structure at a controlled rate. They can be constructed in urban and suburban areas, generally below the trafficked surfaces such as car parks or roads. The European Water Framework Directive prohibits discharge of all polluting substances arising from human activities directly to groundwater and to the watertable. The runoff water may contain substances that can harm the water quality of nearby water catchments, thus affecting the ecology of water catchment habitats, drinking water resources, and amenities.

As hydrocarbon pollution is heavily and constantly carried by runoff stormwater, this water management solution should include pre-treatment of this infiltration to intercept the flow of polluted effluents in order not to damage the aquifers. The aquatextile TenCate GeoClean® is an appropriate solution to clean the polluted water percolating through the whole area of the subbase attenuation layer, either directly into the permeable subsoil, or in a collecting layer when the subsoil is not permeable enough.