Stockton Mine Project

Long-term solution sought for treating Stockton Mine run-off

Options for a long-term solution to Acid Mine Drainage (AMD) solution at Stockton Coal Mine are about to be considered.

AMD occurs when exposed mined rock reacts with air and water, and releases sulphuric acid and heavy metals.

AMD is currently being managed by mine operator, BT Mining Limited, which is retaining the run-off in ponds, neutralising it with lime, and precipitating the heavy metals before it is released into nearby waterways.

AMD treatment is likely to be necessary for at least 80-100 years after the closure of the mine, so an effective long-term solution needs to be identified.

While BT Mining is responsible for the AMD created since it acquired the mine in 2017, the Government is meeting the cost of treating historic AMD that was the responsibility of former State Owned Enterprise, Solid Energy.

Crown-owned company, Ōtākaro Limited is assisting Te Tai Ōhanga The Treasury by managing a project to determine the feasibility of potential long-term treatment solutions. Shortly Ōtākaro will go to the market for expressions of interest.

“Together with a panel of technical experts, our Treaty partners, Ngāi Tahu, and key stakeholders, we’ll look at the options, including continuing with the current approach,” says Ōtākaro Chief Executive, John Bridgman.

“We’ll then make a recommendation to Te Tai Ōhanga The Treasury for approval by Cabinet. The goal is to choose a long-term solution that protects the water quality in the streams and rivers that flow from Stockton Mine, and does so in a cost-effective manner.”