Water - Monitoring

The European Water Framework Directive (WFD) requires environmental quality standards (EQS) to be derived and monitored for the so-called priority substances in water, suspended particulate matter (SPM), sediment and biota. Regular monitoring should ensure compliance with these standards.

Thus far, monitoring has been accomplished by measuring the concentrations of the priority substances in water only, reflecting the fact that biota and sediment EQS can be converted to water concentrations using appropriate bioconcentration factors or partitioning coefficients. This is only feasible when correlations exist between the concentrations in the water phase and in biota, SPM, and sediments. However, problems arise when specific binding mechanisms are involved in bioaccumulation processes, resulting in the absence of correlation. Furthermore, for substances with strong adsorption or bioaccumulation properties, water concentrations may be too low for reliable and cost-effective analyses.

These substances will have to be monitored not only in water, but also in biota and SPM or sediments.