Report No FR0108
THE DEVELOPMENT OF A DYNAMIC RIVER WATER
QUALITY MODEL (SPRAT) FINAL REPORT
To document the development and operation of the dynamic river water quality model known as SPRAT (Spill Pollution Response Assessment Technique).
Intermittent discharges from combined sewer overflows can have a significant impact on river water quality. A dynamic river water quality model is required to enable this impact to be assessed in terms of proposed intermittent water quality standards.
Development of SPRAT has ceased for the foreseeable future and as a result the model described in this report is not a fully supported software product. Readers may wish to consider further development of the model but the FWR bears no liability for its use in its present form.
The introduction of transient pollution standards for the control of intermittent storm sewage discharges requires a new planning/design framework. Within this framework, the use of mathematical tools such as MOSQITO, SPRAT and MIKE-11 will become increasingly important. SPRAT has been developed as a stepping stone between the existing "best available approach" (CARP) and the more sophisticated approach in the MIKE-11 model. As such, the development of SPRAT has served to allow the detailed requirements of the more sophisticated approach to defined and provides the basis for sewerage engineers and river water quality planners to gain experience in the use of the new standards, while still using existing sewer flow models, such as WASSP in conjunction with simple pollution load assessment techniques (SRM2).
V RESUME OF CONTENTS
Section 1 gives a brief background to the development of SPRAT within the context of the Urban Pollution Management research programme.
Sections 2 to 7 gives details of the requirement specification of SPRAT and the various components of the model. These components are flood routing, pollutant routing, sediment transport and biochemical processes.
Sections 8 and 9 cover the operation of the model. Details of the various input and output files utilised and generated by SPRAT during a model simulation are given.
Section 10 is the final section of the report and covers the conclusions and recommendations for future work.
Copies of the report are available from FWR, price £35.00, less 20% to FWR Members.