Conference Agenda

Legacy Mine Impacts
Wednesday, 14/July/2021:
12:40pm - 2:45pm

Session Chair: Julia Dent
Location: Meeting Room 3

12:40pm - 1:05pm

Assessment of the Constraints on Sustainable Urban Drainage Systems Due to Rising Mine Water and Mine Water Management

Lee M Wyatt1, Ian A Watson1, Sally Gallagher2, Joanne Grantham2

1Coal Authority, United Kingdom; 2Environment Agency, United Kingdom

Many urban areas of the UK have underground mine workings, which were dewatered during mining. Cessation of pumping and resultant rising mine water changes the natural and post mining hydrogeological properties of the subsurface. Sustainable drainages systems are the promoted common approach to manage surface water. Groundwater changes can either be influenced by these systems or their presence can influence effectiveness; leading to an increased flooding risk and contrary to the aims of sustainable drainage. This paper describes a trial screening tool developed to help assess the suitability and site specific design of sustainable drainage now and in the future.

1:05pm - 1:30pm

Site Specific Optimisation Assessment Of Circum-neutral Water Treatment Using a Cost-treatability Curve Assessment

James Marsden1, Steven Pearce1, Tim Sambrook1, Julia Dent2, Andrew Barnes3

1Cambrian Environmental Technologies Ltd., 1a Gower Street, Cardiff, Wales, CF24 4PA; 2Mine Environment Management Ltd., 3a Vale Street, Denbigh, Wales, LL16 3AD; 3Geochemic Ltd., Lower Race, Pontypool, Wales, NP4 5UH, United Kingdom

Pollutant load reduction from operational and legacy mine water can pose a financial burden. Many mine sites globally generate discharges in the circum-neutral range. Recent regulatory and social pressures have increased focus on improving discharge quality for these sites. Because treatment of circum-neutral drainage depends on site specific conditions, and is sensitive to water quality targets, an assessment methodology based around a modular approach to water treatment has been developed. This methodology assesses treatment options to meet a range of water quality targets with respect to cost, allowing generation of a cost-treatability curve based on site specific factors or “levers”.

1:30pm - 1:55pm

Evaluating Circum-neutral Mine Drainage: Case Studies of Advanced Testing Methods Generating Representative Empirical Data

Steven Richard Pearce1, Diana Brookshaw1, Seth Mueller2, Andrew Barnes3

1Mine Environment Management Ltd, United Kingdom; 2Boliden Mineral AB, Boliden, Sweden; 3Geochemic Ltd, United Kingdom

Standard acid mine drainage (AMD) characterisation testing methods focus on acidity and can underestimate risks posed by circum-neutral mine drainage. For circum-neutral sites, amended testing methods are required to provide representative empirical data. Case studies of where such amended testing methods have been used to refine assessments of discharge quality from circum-neutral drainage sites are discussed.

1:55pm - 2:20pm

Algae Bioaccumulation Capacity for Metals in Acid Mine Drainage (AMD)-a Case Study in Frongoch Mine, the UK

Tianhao Du1, Anna Bogush2, Paul Edwards3, Peter Stanley3, Luiza C Campos1

1Department of Civil, Environmental & Geomatic Engineering, Faculty of Engineering, University College London, London, WC1E 6BT, United Kingdom; 2Centre for Agroecology, Water and Resilience, Coventry University, Coventry, CV8 3LG, United Kingdom; 3Natural Resources Wales, 29 Newport Road, Cardiff CF24 0TP, United Kingdom

Algae living in the AMD water around the Frongoch Mine, the UK, were collected and identified by microscope. Metals’ concentration was evaluated in AMD water and algae in two seasons (June and October) in 2019 to assess the bioaccumulation capacity of algae. Two types of algae, Ulothrix sp. and Oedogonium sp., were found to be the main species at the Frongoch mine, and they revealed a high capacity of metals bioaccumulation. Concentrations of metals in AMD water from higher to lower were Zn>>Pb>Cd>Fe>Cu. Study results identified the bioaccumulated metals concentrations in algae from higher to lower were Fe>Pb>Cu>Cd>Zn.

2:20pm - 2:45pm

UNEXMIN and UNEXUP Projects: Development of Submersible Robots for Survey of Flooded Underground Mines

Stephen Henley

Resources Computing International, United Kingdom

Submersible robots have been developed in the EU-funded UNEXMIN and UNEXUP projects, for surveying and exploration of flooded underground mines. They carry cameras and instrumentation to determine physical and chemical properties of wall rocks and water. On-board water samplers allow further laboratory analysis of the water.

Trials have been carried out at mines around Europe. Extensive dives yielded much new data on geology and archaeology, as well as the water which in one mine had been almost undisturbed since flooding to river level in the late 1850s. Some information is also presented on an important current project.