LIFE DrainRain is to mitigate the environmental impact of runoff in water bodies (coastal, surface and ground waters). Currently, SUDS only drain runoff water and care needs to be exercised, as infiltration-type SUDS technology may pose a high pollution risk for groundwater bodies. The project takes this approach a step further, by coupling SUDS to treatment systems for diffuse pollution, especially making use of photocatalysts in pavements.

The pilot runoff sustainable drainage and treatment system will consist of several components:

•A pervious concrete photocatalytic pavement with organic pollutants first treated on the concrete’s surface by the photocatalyst Titanium Dioxide;

•A drainage and distribution system in which water is collected by pipes made from anti-microbial materials;

•A hydrodynamic separator that utilises centrifugal energy generated by the water flowing inside to separate suspended solids and oils (SS);

•A filter that comes after the complete retention of SS by a pre-filter to avoid clogging, heavy metals will be removed by adsorption on support materials, such as activated carbon and lignite; and

•An anti-biofouling storage tank, which has been constructed using anti-biofouling high-density polyethylene (HDPE), for storing the regenerated water in a way that ensures microbiological quality.

The project will demonstrate the system in two pilot plants in Spain with different climates (Oceanic and Mediterranean) to promote its wider replication. One area is 900 m2 of pervious concrete surface area in the seaport of Ferrol (Galicia) and the other in Calasparra (Murcia) covers 150 m2 of road hard shoulder.