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Abstract: The European Union Water Framework Directive requires that Management Plans are developed for individual River Basin Districts. From the point of view of faecal indicator organisms (FIOs), there is a critical need for screening tools that can provide a rapid assessment of the likely FIO concentrations and fluxes within catchments under base- and high-flow conditions, and of the balance (‘source apportionment’) between agriculture- and sewage-derived sources. Accordingly, the present paper reports on: (1) the development of preliminary generic models, using water quality and land cover data from previous UK catchment studies for assessing FIO concentrations, fluxes and source apportionment within catchments during the summer bathing season; (2) the calibration of national land use data, against data previously used in the models; and (3) provisional FIO concentration and source-apportionment assessments for England and Wales. The models clearly highlighted the crucial importance of high-flow conditions for the flux of FIOs within catchments. At high flow, improved grassland (and associated livestock) was the key FIO source; FIO loadings derived from catchments with high proportions of improved grassland were shown to be as high as from urbanised catchments; and in many rural catchments, especially in NW and SW England and Wales, which are important areas of lowland livestock (especially dairy) farming, ≥40% of FIOs was assessed to be derived from agricultural sources. In contrast, under base-flow conditions, when there was little or no runoff from agricultural land, urban (i.e. sewerage-related) sources were assessed to dominate, and even in rural areas the majority of FIOs were attributed to urban sources. The results of the study demonstrate the potential of this type of approach, particularly in light of climate change and the likelihood of more high-flow events, in underpinning informed policy development and prioritisation of investment. [Copyright &y& Elsevier]

The nature and magnitude of endemic waterborne disease are not well characterized in the United States. Epidemiologic studies of various designs can provide an estimate of the waterborne attributable risk along with other types of information. Community drinking water systems frequently improve their operations and may change drinking water treatment and their major source of water. In the United States, many of these treatment changes are the result of regulations promulgated under the Safe Drinking Water Act. A community-intervention study design takes advantage of these ‘natural’ experiments to assess changes in health risks. In this paper, we review the community-intervention studies that have assessed changes in waterborne gastroenteritis risks among immunocompetent populations in industrialized countries. Published results are available from two studies in Australia, one study in the United Kingdom, and one study in the United States. Preliminary results from two other US studies are also available. Although the current information is limited, the risks reported in these community-intervention studies can help inform the national estimate of endemic waterborne gastroenteritis. Information is provided about endemic waterborne risks for unfiltered surface water sources and a groundwater under the influence of surface water. Community-intervention studies with recommended study modifications should be conducted to better estimate the benefits associated with improved drinking water treatment. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various reports within the issue on topics including the compliance of water supply system in The Control of Legionella Bacteria in Water System (L8), the importance waterline disinfection, and legionella disease prevention.