Predictive Modelling to aid the Active Management of Bathing Waters Andrew Wither Environment Agency (UK) Science Group

Why do me need predictions? The Public want to know about water quality The new directive will require this knowledge for implementation Compliance can be enhanced

In each bathing site Posting of laboratory result sheets Posting of laboratory result sheets Directly to the beach attendants Posting of informative panels Posting of informative panels 1- Public Information (Other forms of providing public information) SMS service

Bathing sites Reservoirs Supplying and sewer systems Hydraulic Resources EU Reports NewPage Algarve 2004 Bathing Water Classification Annual Syntheses Viv´a Praia Campaign SYNTETHISED DATA Through an INTERNET site an INTERNET site Public Information (National Website)

1- Public Information (National Website) NEW PAGE

Scope and Limitations for Discounting Samples Samples taken during short-term pollution may be disregarded the number of samples disregarded.. may represent no more than 15% of the total number of samples

Choice of Model There are 566 bathing water in Great Britain alone. At most sites predictive modelling will have to be undertaken with little increase in budget. Models will be implemented by non- specialists

Asking the right question The modellers’ task is to produce the best tool using only data that is readily available. Provide a stochastic model relating bathing water quality to basic environmental parameters

Irvine beach: aerial view of River Irvine/Garnock, Ayrshire Compliance point

Model development Simple correlation model for public information (Scotland) Development of correlation model for assessing sample discounting (England) Multiple regression model for forecasting with confidence limits (ICREW)

North West - St Anne’s Prediction PASS, Microb. PASS 78% Prediction FAIL, Microb. PASS 7% Prediction PASS, Microb. FAIL 3% Prediction FAIL, Microb. FAIL 12% Classification change satisfactory - good