Authors: Castendyk, DN; Straight, BJ; Voorhis, JC; Somogyi, MK; Jepson, WE; Kucera, BL

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Castendyk, DN, Straight, BJ, Voorhis, JC, Somogyi, MK, Jepson, WE & Kucera, BL 2019, 'Using aerial drones to select sample depths in pit lakes', in AB Fourie & M Tibbett (eds), Proceedings of the 13th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 1113-1126.

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Regulators often require mining companies to monitor the water quality of pit lakes during closure. Aerial drones, or unmanned aerial vehicles (UAVs), are poised to revolutionise pit lake monitoring and management by: (i) reducing risks associated with water sampling, (ii) lowering costs associated with sampling, and (iii) increasing the frequency of data acquisition. This paper demonstrates how in situ profiles of temperature and specific conductance collected by aerial drones in advance of water sampling can be used to select optimal sampling depths and to inform samplers of the physical state of the pit lake. We provide case studies of drone water sampling at two pit lakes located 295 km apart in the northwest United States. These pit lakes have similar maximum depths, latitudes, and surface elevations, and both require drone water sampling. The Montana Tunnels Pit Lake near Jefferson City, Montana is inaccessible to both foot and vehicle traffic due to previous pit wall failures. The Thompson Creek Pit Lake near Clayton, Idaho has unstable pit walls that as recently as 2016 generated a large landslide that entered the pit lake and produced a tsunami. The health and safety risks associated with future tsunamis have suspended boat-based water sampling. Both pit lakes were sampled during a three-week period in autumn 2018 when most temperate-zone lakes in North America undergo complete top-to-bottom circulation, called ‘turnover’. The aerial drone first suspended a conductivity-temperature-depth (CTD) probe capable of measuring in situ parameters to a depth of 100 m, and then suspended a water sampling device capable of collecting 2 L water samples up to 120 m deep. On 23 October 2018, in situ profiles collected in the Montana Tunnels Pit Lake showed that complete turnover had occurred and informed samplers that a minimum number of water samples would be sufficient to characterise the geochemistry of the water column. The sampling team collected three water samples from 0, 28 and 56 m depths, and subsequent lab results confirmed homogeneous conditions. State and federal regulators observed the sampling event and accepted the water samples for compliance purposes. In contrast, on 13 November at the Thompson Creek Pit Lake, in situ profiles indicated variable water chemistry with depth and the persistence of summer stratification. As a result of this complexity, samplers collected eight water samples from 3, 8, 15, 17, 36, 40, 55, and 83 m depths. In both studies, the aerial drone methods presented herein provided pit lake managers with important information about pit lake behaviour and water quality which could not have been obtained with boat-based methods owing to access and health and safety risks. These studies highlight the potential for future aerial drone water sampling applications during closure.

Keywords: mine void lakes, UAV, UAS, Montana Tunnels Mine, Thompson Creek Mine

Castendyk, D & Eary, TE (eds) 2009, ‘Mine Pit Lakes: Characteristics, Predictive Modeling, and Sustainability’, Society for Mining, Metallurgy, and Exploration, Littleton, Colorado, 304 p.
Castendyk, D, Hill, B, Filiatreault, P, Straight, B, Alangari, A, Cote, P & Leishman, W 2018, ‘Experiences with autonomous sampling of pit lakes in North America using drone aircraft and drone boats,’ in C Wolkersdoffer, L Sartz, A Weber, J Burgess & G Tremblay (eds), Proceedings of the 11th International Conference on Acid Rock Drainage & International Mine Water Association 2018 Annual Conference, International Network for Acid Prevention, Pretoria, South Africa, pp. 1036–1041.
Castendyk, D, Straight, B, Filiatreault, P, Thibeault, S & Cameron, L 2017, ‘Aerial drones used to sample pit lake water quality reduce costs and improve safety’, Mining Engineering, vol. 69, no. 7, pp. 20–28.
Cornell, D, Herman, M & Ontiveros, F 2016, ‘Use of a UAV for water sampling to assist remote sensing of bacterial flora in freshwater environments,’ Undergraduate External Publications, paper 17, St. John Fisher College, Rochester, New York, viewed 1 April, 2019,
Geller, W, Schultze, M, Kleinmann, B & Wolkersdorfer, C (eds) 2013, Acidic pit lakes; the legacy of coal and metal surface mines, Springer-Verlag, Berlin.
IRYS Pty Ltd 2016, ‘Tallering Peak, mid-west Western Australia,’ YouTube video, IRYS Pty Ltd, viewed 1 April 2019,
Koparan, C, Koc, AB, Privette, CV, Sawyer, CB & Sharp, JL 2018, ‘Evaluation of a UAV-assisted autonomous water sampling,’ Water, vol. 10, no. 655, 16 p.
McCullough, CD (ed.) 2011, Mine Pit Lakes: Closure and Management, Australian Centre for Geomechanics, Perth, Western Australia.
Newman, CP, Castendyk, D, Straight, B, Filiatreault, P & Pino, A 2018, ‘Remote water-quality sampling of Nevada pit lakes using unmanned aircraft systems,’ Geological Society of America, Abstracts with Programs, vol. 50, no. 5.
Ore, JP, Elbaum, S, Burgin, A & Detweiler, C 2015, ‘Autonomous aerial water sampling,’ Journal of Field Robotics, vol. 32, no. 8, pp. 1095–1113.
Schultze, M, Boehrer, B, Wendt-Potthoff, K, Sánchez-España, J & Castendyk, D 2017, ‘Meromictic pit lakes: case studies from Spain, Germany and Canada and general aspects of management and modelling’, in RD Gulati, E Zadereev & AG Degermendzhi (eds), Ecology of Meromictic Lakes, Ecological Studies 228, Springer International Publishing.
Terada, A, Morita, Y, Hashimoto, T, Mori, T, Ohba, T, Yagauchi, M & Kanda, W 2018, ‘Water sampling using a drone at Yugama crater lake, Kusatsu-Shirane volcano, Japan,’ Planets and Space, vol. 70, no. 64, 9 p.
Washburn, L, Romero, E, Salazar, D, Valdez-Schulz, A, Welch, Z & Iglesias-Rodriguez, D 2018, ‘Water sampling from aerial drones for water quality research in coastal and inland waters’, 2018 Ocean Sciences Meeting, Association for the Sciences of Limnology and Oceanography, Portland, Oregon, Poster CD14A-0023.
Wetzel, RG 2001, Limnology; Lake and River Ecosystems, 3rd Edition, Academic Press, San Diego.
Williams, D, Haight, S, Jepson, W, Smith, G, Walsh, D, Mohrmann, J, Danesi, D & Bell, C 2018, ‘Surface management inspection, Montana Tunnels Pit Lake, Jefferson City, Montana, U.S. BLM Inspection Report 3809, Butte, Montana, 23 October 2018.

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