A comparative study of past and present water quality in the main stem of the River Ribble, in the upper, mid and lower reaches

Abstract

This investigation studied the River Ribble in autumn 2014 with the intention of comparing current water quality with the Neal et al. study conducted in 2008-2010 in order to assess the impact of the Water Framework Directive (WFD). The Ribble starts in the Pennines and flows east 100km into the Irish Sea; its catchment is a large area of 860 square miles. With few urban areas, 90% of the catchment is rural with extensive agricultural activity. This study focussed on the chemical parameters within the water, these included temperature, pH, electric conductivity (EC), dissolved oxygen (DO), nitrate, chloride, sulphate, phosphate, calcium, magnesium and suspended sediment (SS). Samples were collected and analysed using almost the same methodology as Neal et al.. 3 sites were chosen representing upland, intermediate and lowland reaches of the river. Results are presented in both graphical and tabular format. The findings of this study were similar to those of Neal et al. with respect to pH, magnesium, chloride and nitrate levels. However, sulphate levels showed a marked increase whilst EC results were considerably lower than those revealed by Neal et al.. These differences manifested themselves across all 3 sites with a marked degree of consistency. The findings suggest that, perhaps, the WFD has not yet had a major impact on all aspects of water quality in the River Ribble. The high sulphate readings were not anticipated and may be the effect of effluent discharge from sewage treatment works (STW) upstream from the 3 sites or from agricultural runoff.