Wetlands for Nitrates
Using wetlands to reduce nitrate pollution
Problem: water pollution
Nitrates are Catalonia’s most important groundwater pollution problem. 41% of Catalan groundwaters are in a bad status (nitrate concentrations over 50 mg/L). The origin of this pollution is primarily agricultural (Agencia Catalana del Agua, 2016).
Legal framework:
Water Framework Directive 2000/60/CE
Directive 2006/118/EC, for the protection of groundwaters.
Problem: air pollution
Atmospherical ammonia can increase particulate matter concentrations, with serious health implications. Ammonia emissions are sourced by agricultural and industrial activities.
Legal framework:
Directive 2008/50/CE, for air quality
Objectives of this project
- To prevent and reduce agricultural nitrate pollution in surface and subsurface waters.
- To restore denitrifying ecosystems: wetlands, riparian vegetation and meadows.
- To recover landscape ecological functions for the management of pollution and public health problems.
Wetlands are able to remove nitrogen effectively
Denitrification
- Denitrification is an important function of wetlands and riparian woodlands.
- Denitrification takes place by means of bacterial activity, in anoxic conditions, which are typical of wetland sediments and waterlogged soils.
- Nitrates are transformed into gaseous nitrogen (N2), and returned to the atmosphere.
Project strategy
To restore wetlands in key areas within an agricultural watershed, in order to intercept the highest possible proportion of nitrate. Therefore, working at the landscape scale is the optimal.
Andrena has funded an assessment for a pilot restoration project in the Vic area (Barcelona province). We are advised by scientists at the CEAB-CSIC, ICRA and MN Consultors.
Currently we are talking with landowners of fields within the study area, specifically selected due to their suitable hydrogeological characteristics.
We wish to frame this project within the Natural Climate Solutions strategy.
