In the H2020 UrbanGreenUP some NBS related to water management, such as the NTWP and the Electrowetlands, are designed for the removal of organic compounds and nutrients from the wastewater. The treatment of wastewater by means of green solutions supposes the discharge of low loads of organic matter, nutrients, and other pollutants (such as heavy metals or emerging contaminants) to the environment. Therefore, the safety discharge to the environment or later reuse for different purposes (such as irrigation of green areas) is ensured. This KPI aims at determining the organic matter, nutrients, and other pollutants removal in the NBS. For that purpose, the concentration of the specific contaminants to be monitored are determined both in the influent (raw wastewater) and the final effluent of the NBS. The reduction observed in the concentration is the abatement reached in the monitored system. This KPI involves sampling and analytical determinations in a lab.