WRc has commenced a study for the Environment Agency to review the Fundamental Intermittent Standards (FIS) for dissolved oxygen and ammonia presented in the 1998 second addition of the Urban Pollution Management (UPM2). Originally developed to meet requirements of the Urban Wastewater Treatment Directive, these receiving water standards were produced to protect aquatic life in rivers, from adverse impacts due to intermittent, wet weather discharges from Combined Sewer Overflows and Storm Tanks at Wastewater Treatment Works. Appropriate use of UPM2 guidance and the FIS, in modelling the impact of these discharges, forms a cornerstone of UK policy for controlling their impact on the environment.
For over a decade, FIS standards have been used by water companies to design improvement works to address unsatisfactory intermittent discharges and to support permit applications for wet weather discharges. With the implementation of the Water Framework Directive (WFD), and its new water quality and ecological standards, there is a need to review the degree of protection provided by the UPM FIS against the objectives of the WFD.
Under this project, to be completed by March 2012, WRc will:
- Review the original research used to develop the UPM2 FIS, identify relevant new research, and examine relationships between different UPM standards.
- Develop an effects matrix to show likely ecological effects for a range of concentrations of ammonia and dissolved oxygen at different return periods.
- Compare the effects matrix against existing standards.
- If necessary, propose any alternative UPM standards that will meet the WFD objectives.
- Present the results at a workshop.
For further information contact Bob Crabtree at bob.crabtree@wrcplc.co.uk or 01793 865035