The project’s targets are achieved through material and geotechnical design, environmental biotechnology, lab and field performance testing, integration of data management from monitoring of performance, and quantitative models simulating water quantity and quality at different spatial scales. The layered geotechnical modules are integrated into infiltration and/or drainage systems that can cost-effectively be integrated into the present control structures for stormwater quantities. The solutions will cover a range of site-specific conditions, incorporating on prevailing soil materials, pollutant loads and expected rainfall based on climate change forecasts.
With improved designs based on known mechanisms of contaminant removal, engineered infiltration has the potential to provide reliable treatment of urban stormwater, resulting in a water resource that is safe for aquifer recharge or supporting healthy urban stream ecosystems. The mechanisms by which the chemical and biological contaminants of concern can be removed during infiltration through porous media systems include filtration, sorption, and chemical and biological transformation. The opportunities to effectively optimize treatment of stormwater include choice of infiltration media, manipulation of system hydraulic behaviour, manipulation of redox conditions, and choices of vegetation. The upper exposed surface or pavement layer (asphalt, concrete, paving stones) also has an impact on the potential to bind pollutants or change their rate of sorption by the subbase players.
The ultimate result is to have at least 5 new materials (or significant modifications to existing material products) that can be combined in different geotechnical design configurations to have stormwater cleaning with at least 50% removal of harmful compounds or contaminants (like POC, heavy metals, pesticides, etc.). Stormwater management models, such as SWMM applications, are implemented and tested to account for stormwater quantity and pollutant load generation in the catchment level design of surfacing and infiltration structure locations. New data interpretation and ICT systems will be developed for handling of hydrological and stormwater data in urban landscapes. Cities and water management companies will have new Finnish guidelines that instil confidence to specify, design, construct and maintain the new filtration systems with performance confidence, as well as economic and service-life validity.