Construction and demolition waste in stormwater treatment – StoPWa Final Webinar, June 16, 2026

 Contaminated stormwater generated both in coastal areas and the leaching from inland produces a risk to the quality of water bodies and the Baltic sea. The level and methods of stormwater management vary across cities and municipalities and the problem is often overlooked. On the other hand, demolition of buildings creates vast amounts of construction and demolition waste (CDW), which is difficult to recycle and often ends up in landfills.

The aim of StoPWa project was to develop, design and build applications for the treatment of stormwater, through which the contaminants will be removed and/or degraded. The StoPWa project specifically aimed at finding a novel way to reuse or recycle underutilized fractions of CDW in stormwater treatment.

The webinar introduced new information generated in the project, including properties of recycled materials as a filter, real-life applications and environmental sustainability. Teams from six project partner organisations presented their activities and findings.

Webinar presentations are available via the links below:

Foreword and introduction of project StoPWa | Arto Pennanen, City of Lahti

Agglomeration of mixed CDW for stormwater filtration | Ville Lahtela, LUT University

Filtration studies on concrete and agglomerated CDW filter media | Priit Tikker, Tallinn University of Technology 

Leaching and filtration of agglomerated CDW filter media | John Allen, University of Helsinki

Implementation and findings from stormwater field pilots | Arto Pennanen, Tiina Beldsinsky (HOL), Vita Grigule (Smiltene)

Environmental impacts of stormwater treatment options | Ishika Weerawardhana, LUT University

Techno-economic assessment of CDW-derived filter | Qaisar Munir, LUT University 10.50