Table 1.

Ten problems and recommendations for improving the success of WFD implementation.

No	Problem	Recommendation
Improve monitoring and strengthen comprehensive prioritization
1	Absence of toxic stress cannot be monitored on a per-chemical basis due to large number of chemicals and mixtures.	Integrate effect-based tools into monitoring of water quality.
2	Concentrations and EQS for many hydrophobic chemicals in water are very low and evaluation of exceedance in water is hampered by insufficient analytical procedures and focus on whole water samples (although a move to monitoring such chemicals in biota has been made).	Apply passive sampling for improved compliance check of hydrophobic, bioaccumulative chemicals, with EQS and for temporally representative monitoring of polar substances.
3	Monitoring and assessment tends to emphasize well known and regulated chemicals and to overlook emerging compounds (although watch-list monitoring is helping to change the emphasis).	Use an integrated strategy for prioritization of chemical contaminants, taking knowledge gaps into account.
Foster consistent assessment
4	Different groups of chemicals are addressed in two independent assessments (chemical status and status of River-Basin Specific Pollutants) hampering integrated evaluation. The use of only two quality classes (good and not good) neglects improvements and hampers prioritization of effective control measures.	Consider all relevant chemicals (priority substances and River Basin Specific Pollutants) and use a graded system to assess the chemical status of water bodies.
5	Effect-based monitoring and assessment is hampered by a lack of trigger values.	Define and use effect-based trigger values to address priority mixtures of contaminants.
6	Quality goals of WFD are frequently missed due to historical burdens of persistent organic pollutants (POPs) and metals in sediments.	Consider the toxicity and mobility of historical contaminants accumulated in sediments.
7	Incoherent and insufficient monitoring often leads to ignorance of relevant chemicals and peak concentrations resulting in unrecognized risks.	Consider exposure, effect and risk modeling as a tool to fill gaps in monitoring data and create incentives to extend the monitoring basis of chemical contamination across Europe.
Support solution-oriented management
8	Strategies to identify causes of exceedance of effect-based trigger values and establish cause-effect relationships are missing.	Use a tiered approach of solution-oriented investigative monitoring including effect-directed analysis to identify toxicity drivers and abatement options.
9	Chemicals with the potential to affect water quality are covered by different regulatory instruments resulting in a lack of consistency.	Improve links across environmental-, chemical- and product-specific legislative frameworks and harmonize chemical legislation among Member States
10	There is often a mismatch between assessment outcomes and their usefulness for management.	Apply solutions-oriented approaches that explore risk reduction scenarios before and along with risk assessment.