On-line monitoring of micropollutants in the River Trent (UK) with respect to drinking water abstraction

Abstract

Severn Trent Water (STW) have been investigating the potential of using the River Trent as a drinking water supply resource. Supply and demand assessment during recent semi-drought conditions in the United Kingdom over the last few years indicates that there is a need to utilise Trent water to safeguard supplies for the East Midlands area of England when stocks derived from the River Derwent catchment are limited. The River Trent contains the treated sewage effluent from four million people plus industry in the Midlands and along with diffuse drainage sources means that the river quality can be highly variable. In conjunction with various treatment studies on River Trent water, the pollution risks and water quality variations have been examined. The results have been used to develop an on-line monitoring station to give effective river intake protection in line with the risks found. This monitoring includes continuous low level detection (to less than 1μg/l) of multiple pesticide groups including acid herbicides, acheived by a unique development of solid phase extraction and liquid chromatography techniques.