A review of the efficacy of contemporary agricultural stewardship measures for ameliorating water pollution problems of key concern to the UK water industry

The UK water industry faces a number of water quality issues which mean that capital must be spent on treating raw water in order to meet regulatory standards. Moreover, other policies exist that require improved water quality (e.g. the Water Framework Directive) and contemporary regulation is encouraging water companies to deal with the problem at source, rather than relying exclusively on ‘end-of-pipe’ treatment solutions. Given that much of this pollution results from agricultural practices, agricultural stewardship measures could offer a means of source control. Although numerous schemes are available that encourage farmers to adopt environmentally friendly farming practices, uncertainty exists as to the specific impacts of these measures on water quality. This study has, therefore, reviewed the scientific literature to establish those agricultural stewardship measures that have been proven to impact water quality for three pollutant groups of key concern to the UK water industry, namely dissolved organic carbon, nutrients and pesticides. It has been found that, whilst for many measures there is little or no evidence for impacts on water quality, a range of stewardship practices are available that have been proven to improve water quality. Their effectiveness is subject to a number of factors though (e.g. soil type and pollutant chemistry) and so they should be implemented on a case-by-case basis. Further research is needed to ascertain more fully how contemporary agricultural stewardship measures really do impact water quality.