Constructed wetlands and innovative filter technologies

 for a clean water environment

Nutrient loss from agriculture is still a serious and costly environmental problem in Denmark and elsewhere. The quality goals of the European Water Framework Directive for the aquatic environment require a substantial reduction of the nutrient load from agricultural land.

However, current regulatory practice and mitigation measures to reduce nutrient loads are considered insufficient. This calls for a shift of paradigm towards a more targeted approach in order to mitigate site-specific nutrient losses.

A significant pathway for agricultural nutrient losses is subsurface tile drains and ditches that connect fields to surface waters, acting as subsurface highways for nutrients.

The SupremeTech research project suggest disconnecting these subsurface highways by implementing constructed wetlands and drainage filters for trapping nutrients lost by agricultural drainage, thereby reducing the nutrient load to the aquatic environment.