Animal Waste, Water Quality and Human Health

Transport of microbial pollution in catchment systems 181Table 5.8 Geometric mean (GM) and 95% confidence intervals (CIs) of the GM faecal indicator organism (FIO) concentrations(cfu 100 ml −1 ) under base- and high-flow conditions at the 205 sampling points and for various subsets, and results of paired,t-tests to establish whether there are significant elevations at high flow compared with base flow.FIO Base flow High flowSub-catchment land use n GeometricmeanLower95% CIUpper95% CIGeometric Lowermean a 95% CIUpper95% CITOTAL COLIFORMSAll sub-catchments 205 5.8 × 10 3 4.5 × 10 3 7.4 × 10 3 7.3 × 10 4 ** 5.9 × 10 4 9.1 × 10 4Degree of urbanisation bUrban 20 3.0 × 10 4 1.4 × 10 4 6.4 × 10 4 3.2 × 10 5 ** 1.7 × 10 5 5.9 × 10 5Semi-urban 60 1.6 × 10 4 1.1 × 10 4 2.2 × 10 4 1.4 × 10 5 ** 1.0 × 10 5 2.0 × 10 5Rural 125 2.8 × 10 3 2.1 × 10 3 3.7 × 10 3 4.2 × 10 4 ** 3.2 × 10 4 5.4 × 10 4Rural sub-catchments with different dominant land uses≥ 75% Improved pasture 15 6.6 × 10 3 3.7 × 10 3 1.2 × 10 4 1.3 × 10 5 ** 1.0 × 10 5 1.7 × 10 5≥ 75% Rough grazing 13 1.0 × 10 3 4.8 × 10 2 2.1 × 10 3 1.8 × 10 4 ** 1.1 × 10 4 3.1 × 10 4≥ 75% Woodland 6 5.8 × 10 2 2.2 × 10 2 1.5 × 10 3 6.3 × 10 3 * 4.0 × 10 3 9.9 × 10 3FAECAL COLIFORMSAll sub-catchments 205 1.8 × 10 3 1.4 × 10 3 2.3 × 10 3 2.8 × 10 4 ** 2.2 × 10 4 3.4 × 10 4Degree of urbanisation bUrban 20 9.7 × 10 3 4.6 × 10 3 2.0 × 10 4 1.0 × 10 5 ** 5.3 × 10 4 2.0 × 10 5Semi-urban 60 4.4 × 10 3 3.2 × 10 3 6.1 × 10 3 4.5 × 10 4 ** 3.2 × 10 4 6.3 × 10 4Rural 125 8.7 × 10 2 6.3 × 10 2 1.2 × 10 3 1.8 × 10 4 ** 1.3 × 10 4 2.3 × 10 4Rural sub-catchments with different dominant land uses≥ 75% Improved pasture 15 1.9 × 10 3 1.1 × 10 3 3.2 × 10 3 5.7 × 10 4 ** 4.1 × 10 4 7.9 × 10 4≥ 75% Rough grazing 13 3.6 × 10 2 1.6 × 10 2 7.8 × 10 2 8.6 × 10 3 ** 5.0 × 10 3 1.5 × 10 4≥ 75% Woodland 6 3.7 × 10 1.2 × 10 1.2 × 10 2 1.5 × 10 3 ** 6.3 × 10 2 3.4 × 10 3(Continued)