2003 – 2008: Fitzroy Crossing (Western Australia) – E.coli
During the reviewed period of May 2003 to May 2008, positive E. coli counts were
recorded in approximately 14% of samples collected from Fitzroy Crossing borefield.
This groundwater source is under the direct influence of surface water, resulting in
the higher occurrence of E. coli detections than would typically be seen for a
groundwater source.
Less than 2% of positive samples were > 20 most probable number (MPN) per 100
mL. A count less than 20 MPN/100 mL is typically associated with low levels of faecal
contamination of the surface water and is used as a microbiological contamination
benchmark of the raw water (World Health Organisation 2006).