Dr Donata Dubber
Dept. of Civil, Structural & Environmental Engineering
Using faecal sterols and fluorescent whitening compounds to detect human faecal contamination from septic tanks in Irish catchments
Keywords: Pollution Source tracking; domestic on-site wastewater treatment; Contaminant Hydrology; Analytical Chemistry; Fluorescence Spectroscopy; GC-MS.
Efficient water management is a key requirement to protect water resources and secure water supplies for the future. Irish rural river catchments are impacted by diffuse pollution sources from agricultural practices and domestic wastewater treatment systems (DWWTS), most of which are septic tanks. While an increased nutrient load can cause eutrophication of water sources, the contamination by human enteric pathogens is of special concern to regulatory bodies as it can promote the outbreak of diseases.
Bacteriological indicators have been used successfully to indicate faecal contamination but the ubiquitous nature of these organisms makes it difficult to identify actual sources of pollution, i.e. from domestic wastewater, agricultural activities (e.g. farm animals and grazing livestock) or the natural environment (e.g. birds). Some chemical faecal source tracking methods have been reported to be useful techniques when used in combination with traditional microbiological indicators. For example fluorescent whitening compounds (FWC), which are present in laundry detergents, are regarded as good indicators of human contamination. Furthermore distinguishable faecal sterol profiles, i.e. 'sterol fingerprints" for humans, herbivores and birds have been found to be sufficiently distinctive to be of diagnostic value in determining whether faecal pollution is of human or animal origin.
The aim of this study is to establish appropriate analytical methods to measure these chemical indicators in the Irish environment and to test their suitability to distinguish between the environmental impact from agricultural activities and failing DWWTSs. Through the identification of contamination sources mitigation measures can be targeted to the actual source, thereby increasing water management efficiency and human health.
Project Mentor: Prof. Laurence Gill
Project collaborators: Dr. Patrice Behan (DIT)
Project advisor: Prof. Phillip Geary (Newcastle, Australia)