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The objectives of this study were (i) to apportion sources of faecal coliforms (FC) and faecal streptococci (FS) loads from a dairy farm to a stream in the Irvine catchment; (ii) to assess efficacy of pollution mitigation measures installed on this farm; (iii) to assess frequency with which observed FC loads contribute to high risk of failure of coastal bathing water to meet microbial standards. FC and FS loads in a primary stream running through the farm were estimated at up to four stations (above the farm, above the steading, below the farm and below a pre-existing 0.6ha area of open water/wetland), in summer 2004 and 2005. During this period, steading and field mitigation measures were being installed. We estimated that farm FC loads likely to cause bathing water failure were 8.9×108 colony-forming units (cfu) ha−1d−1 (guideline standards) and 1.7×1010 cfu ha−1d−1 (mandatory standards). In 2005, the guideline exceedance risk (42%) was associated about equally with field and steading sources, whereas the mandatory exceedance risk (11%) was mainly due to steading sources. The pond/wetland below the farm reduced these exceedance risks to 20% and <1%, respectively, but was a source of FS at high discharge. The exceedence curves below the farm were similar in 2004 and 2005, despite lower flows and installation of pollution mitigation measures. The results suggest that further mitigation efforts on this farm should be focused on improving management of the steading FC sources and that wetlands to receive steading runoff can be cost-effective mitigation tools for faecal indicator pollution. [Copyright &y& Elsevier]

The European Water Framework Directive requires the integrated management of point and diffuse pollution to achieve ‘good’ water quality in ‘protected areas’. These include bathing waters, which are regulated using faecal indicator organisms as compliance parameters. Thus, for the first time, European regulators are faced with the control of faecal indicator fluxes from agricultural sources where these impact on bathing water compliance locations. Concurrently, reforms to the European Union (EU) Common Agricultural Policy offer scope for supporting on-farm measures producing environmental benefits through the new ‘single farm payments’ and the concept of ‘cross-compliance’. This paper reports the first UK study involving remedial measures, principally stream bank fencing, designed to reduce faecal indicator fluxes at the catchment scale. Considerable reduction in faecal indicator flux was observed, but this was insufficient to ensure bathing water compliance with either Directive 76/160/EEC standards or new health-evidence-based criteria proposed by WHO and the European Commission. [Copyright &y& Elsevier]

Abstract: The EU Habitats Directive requires Member States to consider the potential impact of sewage discharges on protected wildlife populations, but efforts to reduce these threats are constrained by the lack of appropriate water quality guidelines for wildlife. In Scotland, recommendations for higher discharge standards in areas frequented by bottlenose dolphins have been criticised on the basis of scientific uncertainty. This Viewpoint article outlines the background to this issue, and discusses whether the scientific frameworks used for assessing water quality standards for human bathers can realistically be used to develop water quality standards for coastal dolphins. Importantly, it highlights that widely accepted EU standards for human bathers are based on extremely limited scientific data, and argues that unrealistic demands for empirical data from wildlife populations should not prevent more precautionary measures being introduced to reduce disease risks to these species. [Copyright &y& Elsevier]

Three alternative approaches to predicting delivery of faecal indicators from livestock sources to surface water in the catchment of the River Irvine, Ayrshire, Scotland, are described. These are a soil transport model which assumes all E. coli are transported through the soil, a regression model using observed E. coli concentrations in surface waters, and a distributed catchment model (PAMIMO). Each of these is linked to a simple group of equations describing inputs of E. coli from livestock to land, transport and inactivation in the river Irvine and mixing and inactivation in the sea. The models predict E. coli content of bathing water for Irvine beach. The regression model gives the best predictions of bathing water quality. The low values predicted by the soil transport model suggests that preventing surface runoff of faecal indicators from livestock would provide an adequate solution to the problem of bathing water contamination. [Copyright &y& Elsevier]