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Optimising the effects of practical field-scale interventions to reduce faecal indicator fluxes impacting on protected areas as defined in the Water Framework Directive - WQ0203

Description
Faecal indicator organisms (FIOs) are used as parameters to assess the compliance of bathing and shellfish harvesting waters as required by EU Directives. These environments are defined as ‘Protected Areas’ under the Water Framework Directive and member states are required under Article 11 to design ‘Programmes of Measures’ to ensure compliance of protected areas. These programmes should ensure compliance through integrated management of any ‘point source’ effluent discharges containing FIOs (e.g. treated sewage effluents, intermittent discharges from the sewerage system (i.e. CSOs and SSOs) and industrial effluents (principally from the food and drink processing industries, pharmaceuticals manufacturing and paper plants) together with ‘diffuse source’ fluxes of FIOs (principally derived from agricultural livestock rearing in the United Kingdom). Point source discharges of effluents are relatively well understood and tight regulation is in place which has resulted in significant reductions of this pollution pathway in the UK.

However. there is a significant research gap world-wide on the scientific processes operative, the efficacy and practical optimisation of the relatively small range of interventions designed to reduce FIO pollution derived from diffuse sources impacting on Protected Areas. Research in Scotland and Wales suggests significant promise for two interventions, sometimes called Best Management Practices (BMPs). These BMPs encompass the use of Integrated Constructed Wetlands (ICWs) and stream bank protection from livestock access through the construction of Vegetated Filter Strips (VFS).

This project builds on existing and established catchment scale programmes to address the identified information gaps and produce a robust policy evidence-base for DEFRA and interested stakeholders in the farming and regulatory communities.
Three distinct workpackages will deliver:
1. new empirically derived information on the pollutant sources and pathways through Vegetated Filter Strips created by stream bank fencing;
2. parallel empirical data on the efficacy of Integrated Constructed Wetlands for sustainable attenuation of FIOs derived from farm roofs and yards; and
3. combination of the new empirical data with existing survey reports and the international literature to design guidance to the policy and user communities which will be subject to stakeholder consultation and participation as part of the project deliverables.
The work will be delivered through cost-effective extension of existing programmes.

The first, funded by DEFRA, the Environment Agency and the Research Councils is underway in the Eden Demonstration Catchment. This will be supplemented with microbial sampling and source identification through targeted microbial tracer studies to assess the impact of VFS systems on FIO attenuation and, thus, provide empirical data for (i) VFS design and (ii) optimisation of FIO attenuation.

The second, will utilise a full-scale ICW, constructed in Wales with EU funding, this is the only facility in the UK specifically designed to allow research investigations through installed instrumentation for flow measurement and the facilities for manipulation of input volume and pollution strength as well as a terminal ‘capture’ pond to prevent discharge of poor quality effluent fluxes to the wider environment. This full-scale experimental facility will be used to conduct a series of microbial tracer studies to address the 'physics' of the systems, principally their pollution retention characteristics under different flow conditions; as well as the pollutant attenuation potential of the ICW concept and how it might be sustainably and practically maximised.

Finally, the programme will work with stakeholders to utilise the new information in the delivery of practical targeted guidance in both areas (1) and (2) to the farming and regulatory communities.The first, underway in the Eden Catchment, is currently focused on the effects of VFSs on fate and transport of fine sediment which can impact on salmonid fisheries. This will be supplemented with microbial sampling and source identification through targeted microbial tracer studies to assess the installed VFS systems on FIO attenuation and, thus, provide empirical data for (i) VFS design and (ii) optimisation of FIO attenuation. The second, will utilise a full-scale ICW, constructed in Wales with EU funding, this is the only facility in the UK specifically designed to allow research investigations through installed instrumentation for flow measurement and the facilities for manipulation of input volume and pollution strength as well as a terminal ‘capture’ pond to prevent discharge of poor quality effluent fluxes to the wider environment. Finally, the programme will work with stakeholders to utilise the new information in the delivery of practical targeted guidance in both areas (1) and (2) to the farming and regulatory communities.
Objective
Empirical data acquired on FIO source and small-catchment-scale attenuation through VFS: Integration of FIO studies within the Eden demonstration catchment investigations

• Data acquisition on 20 Eden subcatchments to effect catchment characterisation/selection;
A six week field investigation involving:
• screening of 20 subcatchments;
• monitoring/instrumentation of 7 selected subcatchments;
• tracer studies to quantify source from subcatchment FIO generation areas;
• statistical analysis of data;
• report on findings to quantify the sources areas and the effect of VFSs on sub-catchment FIO outlet flux.


Empirical data acquisition on Integrated Constructed Wetlands as FIO, SS, BOD, nitrogen and phosphorus attenuation systems

Conduct a series of experiments at the instrumented ICW at Pwllpeiran to address the General Objectives, specifically:
• four microbial tracer investigations, two in winter and two in summer, to acquire data on: (i) average retention time in this cascading ICW system and (ii) any leakage from the ponds; and
• six challenge tests using a range of appropriate source strengths and flow rates to investigate the attenuation potential of this type of ICW.


Desk research on source strengths and production of final guidance documents incorporating WP1 and WP lessons.

• A desk study to define microbial source strengths for a range of characteristic farm-related effluents and discharges from the farming industry.

• An international literature review on interventions and best management practices designed to limit diffuse pollution by faecal indicator organisms.

• A desk study designed to bring together the international literature on farm wetland design.

• Design manual guidance for farm ICWs relevant to England and Wales based on the new (and unique) empirical information generated in WP2 combined with lessons from the UK work in Scotland by CREH and other groups.
Project Documents
• Abstract : WQ01   (200k)
Time-Scale and Cost
From: 2009

To: 2013

Cost: £451,360
Contractor / Funded Organisations
University Wales, Aberystwyth
Keywords
Bathing Water              
Diffuse Pollution              
Environmental Protection              
Faecal indicator organisms              
Farming              
Microbial Pollution              
Mitigation              
Sustainable Farming and Food Science              
Water Pollution              
Water Quality              
Water Quality and Use