Issue 6, 2019

Provenance of drinking water revealed through compliance sampling


Understanding drinking water hydrochemistry is essential for maintaining safe drinking water supplies. Whilst targeted research surveys have characterised drinking water hydrochemistry, vast compliance datasets are routinely collected but are not interrogated amidst concerns regarding the impact of mixed water sources, treatment, the distribution network and customer pipework. In this paper, we examine whether compliance samples retain hydrochemical signatures of their provenance. We first created and subsequently undertook the first hydrochemical analysis of a novel national database of publically available drinking water compliance analyses (n = 3 873 941) reported for 2015 across England and Wales. k-means cluster analysis revealed three spatially coherent clusters. Cluster 1 is dominated by groundwater sources, with high nitrate concentrations and mineralisation, and lower organic carbon, residual chlorine and THM formation. Cluster 2 was dominated by surface water sources and characterised by low mineralisation (low conductivity and major ion concentrations), low nitrate and high organic carbon concentrations (and hence residual chlorine and THM formation). Cluster 3 shows a mixture of groundwater overlain by confining layers and superficial deposits (resulting in higher trace metal concentrations and mineralisation) and surface water sources. These analyses demonstrate that, despite extensive processing of drinking water, at the national scale signatures of the provenance of drinking water remain. Analysis of compliance samples is therefore likely to be a helpful tool in the characterisation of processes that may affect drinking water chemistry. The methodology used is generic and can be applied in any area where drinking water chemistry samples are taken.

Graphical abstract: Provenance of drinking water revealed through compliance sampling

Supplementary files

Article information

Article type
17 Sep 2018
07 May 2019
First published
29 May 2019
This article is Open Access
Creative Commons BY license

Environ. Sci.: Processes Impacts, 2019,21, 1052-1064

Provenance of drinking water revealed through compliance sampling

M. J. Ascott, M. E. Stuart, D. C. Gooddy, B. P. Marchant, J. C. Talbot, Ben W. J. Surridge and D. A. Polya, Environ. Sci.: Processes Impacts, 2019, 21, 1052 DOI: 10.1039/C8EM00437D

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity