Animal Waste, Water Quality and Human Health

Transport of livestock-derived pathogens within catchments 247Clearly, much more empirical work on microbial attenuation is needed toaugment the datasets presented here and to address the various data gapsidentified. Two areas in particular merit detailed attention. First, a much betterunderstanding is needed of the spatial and temporal variations in microbialsource strengths and pollution risk within different livestock farming systems inorder that pollution “hot spots” can be targeted for remedial action. Oneimportant development in this field is the pioneering modelling work currentlybeing undertaken by ADAS UK Ltd to quantify the proportions of FIOsgenerated by different livestock (e.g. dairy cattle, beef cattle, lowland sheep,upland sheep and broiler chickens) that are released at different points within thelandscape: steadings, fields, streams, tracks, spreading of manure, and soon. (Steven Anthony, ADAS, pers. comm.). Secondly, very little is known of theeffectiveness of BMPs in reducing microbial fluxes at a catchment scale.Longitudinal studies are fraught with difficulties and hitherto the results haveproved somewhat equivocal (Inamdar, Mostaghimi et al. 2002), (CREH 2006).Modelling-based approaches, such as those developed by Collins & Rutherford(2004) and McGechan, Lewis et al. (2008), supported by empirical data, perhapsprovide the most effective way forward.REFERENCESAtwill, E. R., Hou, L., Karle, B. M., Harter, T., Tate, K. W. and Dahlgren, R. A. (2002).Transport of Cryptosporidium parvum oocysts through vegetated buffer strips andestimated filtration efficiency. Applied and Environmental Microbiology, 68(11),5517–5527.Bottcher, A. B., Hiscock, J. G., Pickering, N. B. and Jacobson, B. M. (1998). WAM:Watershed Assessment Model for Agricultural and Urban Landscapes. AmericanSociety for Agricultural Engineers’ 7th International Conference of Computers inAgriculture. Orlando, Florida, US.Boutilier, L., Lake, C., Hart, W., Jamieson, R. and Gordon, R. (2009). Adsorption,sedimentation, and inactivation of E. coli within wastewater treatment wetlands.Water Research, 43(17), 4370–4380.Bradbury, R. B. and Kirby, W. B. (2006). Farmland birds and resource protection in the UK:Cross-cutting solutions for multi-functional farming? Biological Conservation,530–542.Carty, A., Scholz, M., Heal, K., Keohane, J., Dunne, E., Gouriveau, F. and Mustafa, A.(2008). Constructed farm wetlands: Design manual for Scotland and NorthernIreland. Report to the Northern Ireland Environment Agency and the ScottishEnvironment Protection Agency.Collins, R., Donnison, A., Ross, C. and McLeod, M. (2004). Attenuation of effluent-derivedfaecal microbes in grass buffer strips. New Zealand Journal of Agricultural Research,47, 565–574.