Fecal bacteria in the waters of an upland area in Derbyshire, England: Theinfluence of agricultural land use

Long-term data on the dynamics of sanitary indicator bacteria in fresh wate rs is limited. This paper provides a data record of fluctuations in fecal b acterial concentrations in the waters of an upland area of northern England that can be examined in relation to agricultural land use practices and st andards for contact recreation. Concentrations of fecal coliforms (FCs) wer e monitored in the waters of semi-improved sheep pasture on the edge of a l imestone karst system in north Derbyshire, England for a 21-mo period. Data were obtained for three small streams and six water inflows to streams, co mprising the end points of shallow subsurface tile drainage networks and na tural, semi-permanent, channelized overland flows. All sites showed signifi cant contamination by fecal indicator bacteria. A consistent pattern of sea sonal FC concentration change was observed at all sites, with concentration s generally highest during the summer and lowest during the winter. This ma y be explained by land use factors, including higher summer sheep stocking densities and the application of farmyard manure and sewage sludge. Correla tions between changes in bacterial concentration at inflow sites and downst ream changes in streamwater concentration were generally highly significant , providing strong empirical evidence for the assumed causal relationship b etween inflow and streamwater quality. The degree of fecal bacterial contam ination of the streams, particularly during summer months, may constitute a real health risk to recreational cavers using parts of the limestone karst system into which the streams drain.