Traditional plants, such as sedimentation and oil separation systems, meet the minimum legal standards but are ineffective in retaining particles smaller than 50 µm. This limitation represents a critical challenge for water quality and ecosystem protection, as particles such as micro-pollutants and dissolved metals can easily infiltrate the aquatic environment, with potentially serious consequences. To address this issue, SWI Group has developed advanced technologies designed for the targeted and sustainable removal of emerging pollutants, ensuring effective treatment of even the finest particles and thus protecting aquatic ecosystems in a concrete way.
For over twenty years, SWI Group has been providing comprehensive support to its clients, including legal and engineering consultancy, design, and management of stormwater treatment plants, an increasingly urgent necessity in the context of the growing spread of micro and nanoplastics and their ability to infiltrate aquatic ecosystems. The advanced solutions offered by the company aim to combat this environmental issue, ensuring the effective removal of emerging pollutants and promoting sustainable practices for environmental protection. The solutions developed by the company are designed for strategic infrastructures such as highways, ports, airports, and industrial sites. Thanks to innovative technologies, many of which are patented, SWI Group reaffirms its constant commitment to sustainability and technological innovation.

The presence of micro and nanoplastics in highway runoff waters represents an urgent environmental challenge. Traditional plants, such as sedimentation and oil separation systems, cannot retain SMPs, which infiltrate the aquatic ecosystem through road runoff, causing bioaccumulation and consequences for the food chain. These pollutants primarily result from tire wear, road paints, and construction materials, and disperse quickly into the environment, with documented impacts on ecosystems.

An important case study is represented by the Passante di Mestre, a highway artery managed by the Concessionaria Autostradale Veneta, equipped with advanced treatment plants designed by SWI Group. The Passante di Mestre plants use Stormfilter® technology, a patented passive filtration system from the United States that effectively removes suspended solids, nutrients, and metals, including dissolved ones.
This technology treats at least 90% of stormwater, adsorbing the pollutants through specially developed filter cartridges with a mixture of materials selected to maximize pollutant removal. In the examined highway sections, Stormfilter® technology showed an efficiency of over 60% in removing micro and nanoplastics, a highly positive result considering the ineffectiveness of traditional hydrodynamic separators for particles smaller than 70 microns.