For Water Service Providers (WSP) the safety and quality of drinking water provided are of paramount importance. To ensure drinking water safety a WSP must understand the potential hazards of the supply system all the way from catchment to tap [1]. For drinking water source protection, ecosystem services in the catchment area play a vital role in managing source water contaminants. Leveraging off these services and viewing catchment areas as water treatment assets has the potential to complement conventional engineering solutions such as water treatment, as well as reducing public health risks to consumers [2]. This research focuses on riparian buffers specifically as a subprocess of the wider catchment area. These buffers interrupt the movement of contaminants and sediments from non-point source sources such as agricultural land to surface waters [3].
There are many examples exist where stream buffers have been used to improve water quality outcomes [4] [5]. However, when it comes to wider implementation further research is required to establish practical approaches for management that capitalises on ecosystem services [3]. Good practice catchment management is guided through multiple information sources such as water quality data, land use, compliance action, etc. Core to effective management is understanding monitoring data and responding appropriately in the context of protecting water quality can be complicated. This study uses System Theoretic Process Analysis (STPA) to systematically examine the sociotechnical structures involved us managing vegetated buffers in surface water catchments using a theoretical scenario representative of typical surface water supplies. STPA is a hazard analysis methodology based on System Theoretic Accident Modelling Processes (STAMP), which, being founded on systems theory views safety as the emergent property of the system [6]. Using STPA to examine the complex sociotechnical systems involved in managing stream buffers provides a comprehensive set of requirements for appropriate monitoring and management measures as well as leading indicators of safety.
This example provides a valuable test of how taking a highly systematic approach to identifying management requirements using STPA can help to better understand management requirements. Such processes can be used to give more certainty to management approaches and potentially overcome the common bias toward more costly investment in water treatment infrastructure.
References
[1] World Health Organisation, Guidelines for drinking-water quality: fourth edition incorporating the first addendum, Geneva: WHO, 2017.
[2] J. R. Vincent, I. Ahmand, N. Adnan, W. B. Burwell III, S. K. Pattanayak, J.-S. Tan-Soo and K. Thomas, “Valuing Water Purification by Forests: An Analysis of Malaysian Panel Data,” Environmental Resource Economics, no. 64, pp. 59-80, 2016.
[3] M. L. Stutter, W. J. Chardon and B. Kronvang, “Riparian buffer strips as a multifunctional management tool in agricultural landscapes,” Journal of Environmental Quality, no. 41, pp. 297-303, 2012.
[4] F. K. Yeboah, F. Lupi and M. D. Kaplowitz, “Agricultural landowners’ willingness to participate in a filter strip program for watershed protection,” Land Use Policy, vol. 49, pp. 75-85, 2015.
[5] C. Buckley, S. Hynes and S. Mechan, “Supply of an ecosystem service—Farmers’ willingness to adopt riparian buffer zones in agricultural catchments,” Environmental Science and Policy, vol. 24, pp. 101-109, 2012.
[6] N. Leveson, “A new accident model for engineering safer systems,” Safety Science, vol. 42, no. 4, pp. 237-270, 2004.
