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Catchment Modelling Strategies for Faecal Indicator Organisms: Options Review and Recommendations - WQ0220

This project involves a desk study review of available modelling strategies for faecal indicator organism (FIO)microbial parameters in catchment systems. This is needed to provide a policy evidence-base to determine appropriate catchment modelling approaches for the microbial parameters.

Implementation of the EU Water Framework Directive (2000) (WFD) already involves a series of modelling tools for the nutrient and sediment loadings from catchment systems. These models are used to investigate different policy options and guide progress towards compliance with the requirements of the WFD for maintenance of 'good ecological status' within surface waters.

Daughter Directives of the WFD include those covering the quality of bathing waters and shellfish hygiene. These Directives use microbial FIO concentrations to measure the compliance of 'protected areas' defined in Article IV of the WFD. The mechanisms that Member States have to ensure compliance of Daughter Directives with FIO standards are outlined in Article 11 of the WFD. This involves the competent authorites designing a 'Programme of Measures' for integrated control of point and diffuse sources of pollution to ensure compliance of coastal and inland systems with FIO standards.

There are no widely accepted modelling tools available to guide this process in the UK although considerable activity is evident world-wide with a series of candidate model systems being tested in Australia, New Zealand, the USA, Canada and the EU.

This project will identify the range of modelling options available, their individual strengths and weaknesses and their parameterisation requirements if applied to UK catchment systems potentially impacting on WFD protected areas.
7. (b) Objectives

7b.1 Context

DEFRA have utilised export coefficient models to characterise faecal indicator organism (FIO) flux at the catchment scale and determine FIO source apportionment through the FIOSA project . FIOSA comprises an empirically-based, but ‘black-box’, modelling approach. The growing requirement for the design of ‘programmes of measures’ by Article 11 of the Water Framework Directive (WFD), to prevent impairment of Annex IV ‘protected areas’ (i.e. including bathing and shellfish harvesting waters), is generating an imperative for the development of more ‘white-box’, or process-based, modelling capacity. This is needed to underpin prediction and design of remediation strategies particularly in livestock farming areas to facilitate integrated management of diffuse and point-source FIO fluxes.

7b.2 Current status and opportunity

SIMCAT is becoming the modelling platform of choice for WFD catchment modelling by the UK environmental regulators. However, it is not suitable for FIO modelling. A number of modelling systems are being adapted, world wide, to provide FIO components. These include, the PEDAL2, SWAT, HSPF, MIKE11 and several models used by engineering communities which could be commercially available. The principal gap preventing the deployment of available model systems is the absence of empirical data with which to parameterise and evaluate any of these models for test catchments .

The partners in this application have unique UK experience in catchment FIO dynamics and they have generated: (i) extensive empirical data which can be analysed to address key questions such as, for example, characterisation of FIO flow relationships; (ii) land use FIO export relationships; (iii) FIO delivery for known ‘hot-spots’ such as farm hardstanding areas. Additionally, they are both undertaking current empirical work, funded by DEFRA, the EU, the Scottish Government and UK regulators which can assist in extending this empirical data resource to complement any investigations undertaken as part of the Demonstration Test Catchments Initiative.

7b.3 Policy need and project objectives

The ‘short-term’ policy community requirement which this project will address is:-

The provision of a comprehensive review of existing work on FIOs and associated modelling approaches.

The project will be delivered via three workpackages as identified in Section 7c.1. Specifically, the objectives of this proposal are:

1. to identify current world-wide candidate models for UK application with regard to the prediction of microbial watercourse pollution, following a comprehensive literature review;
2. to assess the likely parameterisation and performance evaluation data requirements of the candidate models in order to develop UK modelling capability; and
3. to undertake consultation with stakeholders and model end-users in appropriate UK agencies to agree the modelling recommendations and most promising model platform(s)

Project Documents
• FRP - Final Report : WQ0220 Milestone 2   (675k)
• FRP - Final Report : WQ0220 Milestone 3   (2019k)
• ROAME Document : WQ01   (200k)
Time-Scale and Cost
From: 2010

To: 2016

Cost: £76,808
Contractor / Funded Organisations
CREH Analytical Ltd
Faecal indicator organisms              
Scoping study              
Sustainable Farming and Food Science              
Water Quality and Use