Animal Waste, Water Quality and Human Health

Transport of microbial pollution in catchment systems 167severely limits the effectiveness of control measures and prevents prioritisation ofsource water protection activities in catchments. Without such data it is difficult todetermine which factors are most important in mitigating catchment risks sincecontrol of animal population density, volume and location of excreta, andanimal behaviour can only be effective if measures target the right animals.Table 5.4Concentration of Giardia cysts in animal faeces.Ranking Animal Age n* Mean concentration/g Median concentration/g1 Muskrat adult 1 9574 95742 Bison adult 1 2649 26493 Beavers adult 1 1654 16544 Coyotes adult 1 1577 15775 Cattle juvenile 2 1519 15196 Deer adult 1 1168 11687 Cattle adult 6 1013 34.28 Elk adult 2 832.5 832.59 Ducks adult 1 444 44410 Moose adult 1 168 16811 Pigs adult 2 42 4212 Sheep adult 1 20 2013 Fox adult 1 0 014 Geese adult 1 0 015 Hare adult 1 0 016 Horses adult 1 0 017 Porcupine adult 1 0 018 Rabbits adult 1 0 019 Rodents adult 1 0 020 Squirrels adult 1 0 0*Number of published studies (not the number of samples analysed).The number and size of domestic livestock studies performed were probablysufficient for use in initial modelling efforts. However, the Cryptosporidiumprevalence data suggested there was some geographic variability that needs tobe considered when estimating risk at a specific location. Although the risksfrom wildlife species are thought to be lower than from domestic livestock,there were few studies and sample numbers were often low. Hence, relying onpublished data sets alone to estimate risk would not be recommended. It isrecommended that to estimate the risk posed by wildlife at a specific location,local studies of pathogen prevalence and concentrations are performed to