Water pollution has a significant negative impact on human health and the environment, and improving the quality of rivers, lakes, groundwater and coastal waters is a priority for policymakers. The European Water Framework Directive (WFD) was established to protect and improve water quality and prevent further deterioration, through legal limits on a wide range of known pollutants. The Water Framework Directive specifies a list of 33 priority water pollutants, for which maximum allowable concentrations have been defined. As some pollutants are toxic to a wide range of living organisms, the permitted levels are very low and challenging to measure and monitor.
This project addressed the measurement requirements for a group of toxic pollutants: tributyltin (TBT), polybrominated diphenylether (PBDE) and selected polycyclic aromatic hydrocarbons (PAH). The project developed:
- Validated reference methods for the analysis of TBT, PBDE and PAH traceable to the SI units at the levels and uncertainties required by the Water Framework Directives. Importantly the methods address measurements in ‘whole water’ i.e. in real-world samples where pollutants can be present as suspended solids or colloids as well as in solution.
- Aqueous reference materials for TBT, PBDE and PAH at ng/L levels with proven short and long time stability. The materials contain dissolved humic acids and suspended particulate matter and are a major step forward towards producing reference materials that mimic whole water.
The project conducted an interlaboratory comparison for field laboratories using the new aqueous reference materials at low concentrations (ng/L for some parameters). This demonstrated that most parameters could be successfully measured with reasonable agreement between the laboratories and was a significant achievement as no such intercomparsion has been performed before on whole water samples with such low concentrations. This means that accurate measurement capabilities and quality assurance are now available to enable water monitoring laboratories to meet the requirements of the Water Framework Directive.