Mine water geochemistry and metal flux in a major historic Pb-Zn-F orefield, the Yorkshire Pennines, UK

Abstract

Recent studies have shown up to 6 % of rivers in England and Wales to be impacted by discharges from abandoned metal mines. Despite the large extent of impacts, there are still many areas where mine water impact assessments are limited by data availability. This study provides an overview of water quality, trace element composition and flux arising from one such area; the Yorkshire Pennine Orefield in the UK. Mine drainage waters across the orefield are characterised by Ca-HCO3-SO4-type waters, with moderate mineralization (specific electrical conductance: 160-525 μS cm(-1)) and enrichment of dissolved Zn (≤2003 μg L(-1)), Ba (≤971 μg L(-1)), Pb (≤183 μg L(-1)) and Cd (≤12 μg L(-1)). The major ion composition of the waters reflects the Carboniferous gritstone and limestone-dominated country rock, the latter of which is heavily karstified in parts of the orefield, while sulphate and trace element enrichment is a product of the oxidation of galena, sphalerite and barite mineralization. Contaminant flux measurements at discharge sites highlight the disproportionate importance of large drainage levels across the region, which generally discharge into first-order headwater streams. Synoptic metal loading surveys undertaken in the Hebden Beck sub-catchment of the river Wharfe highlight the importance of major drainage levels to instream baseflow contamination, with diffuse sources from identifiable expanses of waste rock becoming increasingly prominent as river flows increase.

Zinc Uptake from Circumneutral Mine Drainage in Freshwater Biofilms: New Insights from In Vitro Experiments

“…Biofilm was collected on the day of the experiment and transported so as to avoid denaturing of the biofilm. Biofilm and water was collected from Dukes Level mine discharge (Lat 54°04 0 43N, Long 1°57 0 41W), a major mine drainage level with ambient Zn concentrations of 950 lg L -1 and major ion chemistry characterised by Ca 2þ ÀHCO À 3 ÀSO 2À 4 -dominated waters (see Jones et al 2013). Biofilm (see supplementary Figure 1, which accompanies the on-line version of this paper) had spontaneously colonised on the mine drainage level discharge, which is a concrete structure.…”

“…For the biofilm to colonise, a suitable substrate should be made available. When initially developing this system, carbonic pads were attached to roof slates and deployed at the mine-affected Hebden Beck stream in North Yorkshire (Jones et al 2013) and left in-stream to allow the colonisation biofilm over a 3 month period, which is the optimal length of time to allow development of a biofilm to full maturity ). However, high flow events during summer 2012 led to the scouring (and thus removal) of biofilm communities from the colonized roof slates.…”

“…Over 6 % of rivers in England and Wales have metal concentrations that exceed aquatic life standards due to metal mine discharges (Mayes et al 2009a). 85 % of such discharges have a pH between 6 and 8, while about 5 % have a pH\4 (Jones et al 2013;Mayes et al 2010). The most common metal pollutants in these circumneutral discharges are Zn [ Pb [ Cd [ Cu (Jarvis and Mayes 2012).…”

“…Zachara et al 1991), and this process would not occur under the chemical regime of the ambient water (Rogerson et al 2008). A recent field assessment of biofilm Zn concentrations in circumneutral streams draining areas of former Pb and Zn mining in North Yorkshire, UK, showed median Zn concentrations of 1,800 mg/kg dry weight (range 800-4,100 mg/kg dry weight), a bioconcentration factor of over 3,500 from the water column under baseflow conditions (Jones et al 2013). There is, therefore, considerable opportunity to use biofilm as a tool to remediate areas that are affected by mine drainage.…”

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

“…This includes analysing metal contaminants in wastewater using: biosensors (Eltzov et al 2015), optical systems (Gómez-de Pedro et al 2014) and electrochemical techniques (Bansod et al 2017). However, further work is needed to develop simple, reliable, and cost-effective techniques for remote detection of pollutants, to better understand processes that regulate metal dispersion and allow for an emergency response to unexpected events (Byrne et al 2013;Cidu et al 2011;Jones et al 2013;Lynch et al 2017). No single system available today can fully meet the needs to determine, in real-time, the composition of water to the desired sensitivity level and cost-effectiveness for effective remediation and long-term monitoring of water bodies affected by metal mine drainage.…”