Chemistry

SEPA's chemistry function plays an integral role in ensuring that the objectives of the Water Framework Directive (WFD) are achieved in terms of the chemical monitoring, analysis and data assessment that SEPA carries out.

Priority substances

The WFD's objective of achieving good ecological status of a water body will be achieved when, amongst other criteria, good chemical status is achieved. The achievement of good chemical status is dependant on meeting agreed environmental quality standards (EQS), including EQS for priority substances.

The European Commission has identified a list of 33 priority substances based on their toxicity, persistence and liability to bio-accumulate in the environment. The list will be reviewed by the Commission every four years and is divided into two categories (depending on the level of concern):

  • Priority substances
  • Priority hazardous substances

Measures to address these priority substances must be implemented with the aim of:

  • Cessation or phasing-out of discharges, emissions and losses of priority hazardous substances by 2025;
  • Progressive reduction of pollution from all priority substances.

Specific pollutants

The WFD provides an indicative list of main pollutants to be considered as 'specific pollutants'. Good ecological status also requires concentrations of specific pollutants to be below the EQS. Member States are responsible for developing appropriate EQS for specific pollutants.

UK work

Chemistry involvement in the implementation of the WFD on a UK national scale is managed through the UK Technical Advisory Group (UKTAG) Chemistry Task Team. This group is part of the UKTAG network and exists to provide technical advice on chemical aspects of the Directive.

Further information on SEPA's chemistry function can be found in the Scotland's environment section.