Chemical Quality Status of Rivers for the Water Framework Directive: A Case Study of Toxic Metals in North West England

Abstract

This paper provides data from two years of monitoring of the chemical quality of rivers and streams in North West England from the clean headwaters to polluted rivers just above the tidal reach and covers 26 sites including the Ribble, Wyre and the tributary rivers of the Calder and Douglas. Across the basins that include areas of rural, urban and industrial typologies, data is presented for three of the priority substances in the Water Framework Directive i.e., nickel (Ni), cadmium (Cd), and lead (Pb). Average concentrations are low and well below the Environmental Quality Standards values for all three of these substances. Cadmium and Pb appear in approximately equal proportions in the dissolved (<0.45 µm) and in the acid available particulate fractions (>0.45 µm) whilst Ni occurs predominantly in the dissolved form (92%). Regional inputs of these metals arise mostly from diffuse sources as the storm-flow concentrations are generally greater than at base-flow condition. Greater concentrations of Ni are transported at the headwaters and smaller tributary sites under storm flow condition than for the main stream of the Ribble. For Ni, amounts increase as the river proceeds from its headwaters down towards the Ribble and Wyre estuaries, whilst Cd and Pb show consistent values throughout the catchment. There is annual cycling of dissolved concentrations of Cd, Pb and Ni for the clean headwater streams that gives maxima during the latter half of the year when the river flow is greater. For the impacted sites the pattern is less distinct or absent. Our estimates

Lowland river water quality: a new UK data resource for process and environmental management analysis

“…The current risk associated with diffuse and point source inputs of the priority substances associated with the Water Framework Directive is low. Rowland et al (2010c) found no annual average concentrations of dissolved Pb, Cd, Ni and Hg in the Ribble and Wyre catchment above the regulatory Environmental Quality Standard values, and neither were there any values exceeding the defined maximum allowable concentrations. Comparing more recent data for the Ribble and Wyre (Neal et al, 2011a) with earlier studies of the eastern UK rivers (Neal and Robson, 2000;Neal and Davies, 2003) indicates that pollutant concentrations have generally declined over the past 20 years when considering similar catchment typologies.…”

Field observations to establish the impact of fluvial flooding on potentially toxic element (PTE) mobility in floodplain soils

“…These are generally released into the environment from anthropogenic sources (Álvarez-Ayuso et al, 2012;Förstner, 2004;Prabakaran et al, 2019;Rennert et al, 2017). Floodplains located in urban catchment areas are contaminated from sources including wastewater/sewage treatment plants, factories using alloys, metal mining, landfills, and road surface runoff from tyre and brake emissions into the river (Hurley et al, 2017;Rowland et al, 2011;Stuart and Lapworth, 2011). Soils have the ability to retain Much of the understanding about the influence of flooding on PTE mobility in floodplains has come from laboratory experiments undertaken in mesocosms.…”

Comparison of Electromagnetic Wave Sensors with Optical and Low-frequency Spectroscopy Methods for Real-time Monitoring of Lead Concentrations in Mine Water

“…The UKTAG established an environmental quality standard (EQS) for dissolved Pb in surface water of 7.2 ppb (Rowland et al 2011). Generally, the ionic form of Pb (Pb 2+ ) is considered most toxic.…”