After decades of regulation and investment to reduce point source water pollution, OECD countries still face water quality challenges (e.g. eutrophication) from diffuse agricultural and urban sources of pollution, i.e. pollution from surface runoff, soil filtration and atmospheric deposition. The relative lack of progress reflects the complexities of controlling multiple pollutants from multiple sources, their high spatial and temporal variability, the associated transactions costs, and limited political acceptability of regulatory measures.
The OECD report Diffuse Pollution, Degraded Waters: Emerging Policy Solutions (OECD, 2017) outlines the water quality challenges facing OECD countries today. It presents a range of policy instruments and innovative case studies of diffuse pollution control and concludes with an integrated policy framework to tackle this challenge. An optimal approach will likely entail a mix of policy interventions reflecting the basic OECD principles of water quality management – pollution prevention, treatment at source, the polluter pays and the beneficiary pays principles, equity, and policy coherence.
For more information, OECD Green Talks Live on Degraded Waters: Emerging policy solutions to tackle diffuse pollution - Hannah Leckie and Xavier Leflaive of the OECD Environment Directorate discussed emerging solutions in OECD countries, that can guide the design and implementation of policies to control diffuse water pollution.