Monitoring pesticide pollution in European rivers, lakes and groundwater

Pesticide monitoring data in European Waters

The Water Framework Directive (WFD) and its daughter directives on environmental quality standards and groundwater[1] set quality objectives to protect water from pesticide pollution. According to the WFD, pesticide concentrations above threshold levels lead to surface waters failing to achieve ‘good chemical status’, based on pesticides listed as priority substances, and ‘good ecological status’, based on pesticides listed as river basin-specific pollutants. The WFD also lists pesticides that are groundwater pollutants to assess the chemical status of groundwaters.

Countries can submit detailed monitoring data[2] via the WISE SoE[3] (labelled WISE-6) data flow to the European Environment Agency (EEA). Up to 38 countries have contributed data on rivers, lakes, and groundwater to the Waterbase Water Quality database produced from WISE-6, improving precision and comparability.

Waterbase – Water Quality supports tracking of progress under the EU water policies, including directives, action plans and strategies[4]. This data flow collects harmonised data on water quality, e.g. pollutant concentrations. By harmonising the data collection and reporting methods across all member states, it ensures that assessments are based on the same criteria, it supports transparent assessment, highlights areas in need of improvement, and tracks the progress of water policies across Europe. Differences in sampling and analytical methods, pesticide coverage, and monitoring distribution between countries and years need to be taken into account when interpreting the results.

Thresholds used to assess exceedances

Effect thresholds for surface water and quality thresholds for groundwater in water assessment refer to concentration limits of pollutants (such as pesticides) above which harmful effects on organisms or ecosystems are likely to occur. If a measured concentration in water is above the threshold, it is considered an exceedance, indicating potential ecological or health risks. To assess pesticide exceedances, effect thresholds were assigned to each pesticide:

• Surface waters: Based on ecotoxicological thresholds, prioritising:
• EU Environmental Quality Standards [5](EQS)[6]
• Watch List maximum detection limits (per Commission Decisions)[7]
• River Basin Specific Pollutant EQS (lowest national value used, differing national criteria limit direct comparisons)[8]
• Selected national regulations
• Stockholm Convention (Persistent Organic Pollutants)[9]

• Groundwater: Assessed against the 0.1 µg/L standard in the Groundwater Directive[10]. Non-relevant metabolites were excluded due to lack of regulated thresholds.

Effect thresholds are established to ensure that concentrations in water bodies remain below levels that could harm the environment or human health. When measured concentrations exceed these effect thresholds, it means that organisms are at risk of experiencing harmful effects.This exceedance signals the need for regulatory adjustments and potentially stricter measures (e.g. stricter limit values).

More detailed information on the methodology is available here (The methodology document needs to be updated to the newest methodoly, after consultation process is finished.)

Notes

[1] Proposal for a Directive amending the Water Framework Directive, the Groundwater Directive and the Environmental Quality Standards Directive.

[2] Measured concentrations in µg/L

[3] Water Information System for Europe – State of the Environment

[4] providing support for monitoring requirements and approaches for tracking progress towards the implementation of the 8th Environmental Action Plan and European Green Deal, including EEA’s input to mid-term reviews of underlying policies, particularly the Biodiversity Strategy for 2030, Farm to Fork Strategy, the Zero Pollution Action Plan

[5] https://water.europa.eu/freshwater/europe-freshwater/water-framework-directive/surface-water-chemical-status

[6] https://eur-lex.europa.eu/EN/legal-content/summary/environmental-quality-standards-applicable-to-surface-water.html#:~:text=WHAT%20IS%20THE%20AIM%20OF,over%20a%201%2Dyear%20period.

[7]https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=OJ:L_202500439

[8] https://water.europa.eu/freshwater/resources/metadata/wfd-dashboards/surface-water-methodology-standard-types-and-threshold-values-for-river-basin-specific-pollutants-country-overview

[9] https://eur-lex.europa.eu/eli/convention/2006/507/oj/eng

[10] https://eur-lex.europa.eu/eli/dir/2006/118/oj/eng

The pesticide indicator methodology evaluates pesticide concentrations in surface water and groundwater water bodies between 2020 and 2023 against set effect or quality thresholds. If one or more pesticides exceed these thresholds, it results in the corresponding water body being classified as exceeded. A detailed description is provided in "Methodology for indicator on pesticides in European waters".