Understanding current and future impacts of public water supply on macronutrient cycles around the world

The macronutrients Nitrogen (N) and Phosphorus (P) are essential for life, yet also represent threats to both ecosystem and drinking water quality in many parts of the world. Recent research by the supervisors [1-3] revealed that public water supply (PWS) processes are associated with significant fluxes of N and P, due to abstraction and mains water leakage alongside wastewater discharge. Beyond this research conducted in the UK, very little is known about how these processes currently influence macronutrient cycles around the world, nor about the likely impacts of future changes in climate and population on these processes. Addressing these issues lies at the heart of the proposed PhD. This work is particularly important because global variation in factors such as abstraction and leakage rates, N and P concentrations in raw waters, and the extent of environmental regulation will likely drive significant variation in the impacts of PWS on N and P cycles around the world. Countries undergoing rapid development are expected to see drastic changes in PWS infrastructure, with increases in abstraction and development of large-scale water transfers, which may result in significant impacts of PWS on N and P cycles.

Working between Lancaster University, BGS and key in-country partners, this multidisciplinary PhD has the overarching aim of developing improved conceptual understanding and quantification of the impact of PWS on macronutrient cycles in three contrasting settings: China; USA and globally. For each setting, specific objectives are to:

(1) Quantify current N and P fluxes associated with PWS processes;
(2) Model the impact of future changes in PWS (e.g. changes in abstraction, distribution, leakage, wastewater treatment and water transfers) on N and P fluxes; and
(3) Extend the work to complete objectives (1) and (2) to other macronutrients (e.g. carbon), alongside other elements of potential interest, e.g. silica.