Monitoring and tracking contaminant sources in catchments and estuaries

In managing water quality in catchments and estuaries, faecal contamination is typically assessed using microbial indicators, such as faecal coliform bacteria. Bacteriological indicators however cannot be used to distinguish whether the faecal contamination has been derived from human or animal sources. The ability to track contamination and distinguish between sources is particularly important where water is used for potable supply, recreational purposes and where commercial aquaculture for human consumption is undertaken. Various chemicals associated with human metabolism and activities which are present in faecal material (such as faecal sterol, pharmaceutical and fluorescent whitening compounds present in wastewaters) can be utilized to identify a human signal and therefore whether the faecal contamination in water is likely to have been derived from human sources. This paper demonstrates an approach and methodology for future work using a combination of these methods to distinguish human contaminant sources in stormwater runoff in an estuary where aquaculture is practised.