TFIP001: Distinguishing contaminant export from mixed land use to estuarine environments
(Tilligerry Creek, NSW)
Download the project sheet here.
Project Managers
Dr Phillip Geary
Dr Steven Lucas
Partners
The Integrated Water Cycle Management Group (School of Environmental & Life Sciences, The University of Newcastle) – Dr Phillip Geary, Steven Lucas, A/Prof Peter Coombes and A/Prof Hugh Dunstan
Port Stephens Council.
Aims
To evaluate microbial and nutrient export from an unsewered area at Salt Ash and quantify the impact of these exports to the Tilligerry Creek estuary. 
Background
Previous work in the area has shown that specific catchment conditions such as high groundwater levels and high rainfall enhance contaminant transport from surrounding catchment areas. Periodic contamination of the estuary has resulted in several oyster farm closures in the past 18 months. Detailed studies are being undertaken in this unsewered area to understand the specific “drivers” for contaminant export towards the Tilligerry Creek estuary (Figure 1).
Project Scope
Faecal biomarkers such as sterol compounds (eg, coprostanol) and microbial indicators (eg, E.coli) have been used as tracking methods to distinguish between sources of contamination. Many of these methods are being further developed in order to recognise the chemical/microbial “signature” of waters within a specific catchment, as well as determining sources from particular landuses. 
Surface water and groundwater quality data and results from the continuous monitoring of surface drain level and groundwater depth will be interpreted in conjunction with climatic conditions and human inputs to understand the processes of contaminant export to the estuary.
Over the next 12 months, an estuary response model will be developed to improve our understanding of contaminant transport within the estuary, such as the influence of tidal factors and the circulation of estuary waters before/after rainfall. Outcomes from this study will assist Port Stephens Council in the design requirements for the sustainable use of on-site wastewater systems and other land uses in similar sensitive coastal locations (i.e. estuarine environments).