145-10 Potential Impacts of a Failure of the Dry Stack Facility at the Proposed Dalradian Gold Curraghinalt Mine in Northern Ireland on the Rivers of the Republic of Ireland

Session: Dynamics of Natural and Built Environments (Posters)

Presenting Author:

Author:

Abstract:

The proposed Curraghinalt Gold Project in Northern Ireland would store 4.8 Mm³ of mine waste in a “Dry Stack Facility” (DSF). The filtered tailings will have a water content of 15%, so that “Dry Stack Facility” is a marketing term. The objective of this study is to consider the potential impacts of failure of the DSF on the rivers of the Republic of Ireland. Recent failures of filtered tailings facilities have included the Pau Branco mine in Brazil in 2022, the Cuzcatlán mine in Mexico and the Turmalina mine in Brazil in 2024, and the PT Huayue Nickel Cobalt and PT Qing Mei Bang (QMB) New Energy Materials mines in Indonesia in 2025. Consequences have included highway burial (Pau Branco), water supply contamination (Cuzcatlán), evacuation of 134 residents (Turmalina), and three fatalities (PT QMB). A updated statistical model predicts that the initial tailings runout will cover 20 kilometers along Pollanroe Burn, Owenreagh River, and Owenkillew River in the most-likely scenario (release of 34% of the tailings). In the worst-case scenario (release of 100% of the tailings), the initial runout will cover 65 kilometers, including River Mourne and 17 kilometers of River Foyle, as it flows along the border between Northern Ireland and the Republic of Ireland. Subsequent flow will transport the tailings to Lough Foyle, an estuary of the Atlantic Ocean. Tidal currents could transport tailings from River Foyle upstream into River Finn for 11 kilometers, along the border and into the interior of the Republic of Ireland. The failures at the Pau Branco and Turmalina mines involved slumping for distances of 17.25 and 21 times the respective heights. Assuming a slump of 20 times the height, a solid slump from the DSF (height of 59 meters) would carry the tailings for 1180 meters with multiple entry points into Pollanroe Burn, where a liquefied flow could develop. Based upon past measurements, the peak tailings velocity will exceed 100 kilometers per hour, so that the tailings flood will reach the confluence of Pollanroe Burn and the Owenreagh River (2296 meters along Pollanroe Burn) in 1-2 minutes. Based upon a mean velocity over the initial runout of 35 km/h, the tailings flood will cover the most-likely and worst-case runout distances in 34 and 111 minutes, respectively.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-7263

© Copyright 2025 The Geological Society of America (GSA), all rights reserved.