The mining company is seeking to reduce the melt water in the operational area of the mine to ensure sufficient capacity for water necessary to the mine’s bioleaching process.
The amount of water referred to in the permit is roughly equivalent to around two lorry loads per minute. According to Talvivaara, the water can be pumped away without being run through their purification systems.
Pursuant to Article 62 of the Environmental Protection Act, Talvivaara on Friday submitted another application to release the additional quantities of waste water.
Water by the lorry load
Talvivaara mine wants to drain around 800 cubic metres per hour of rain and melt water from the mining area through Torvelansuo’s water treatment plant and release it towards Vuoksi in the south. Talvivaara already releases around 1,300-1,500 cubic metres per hour of water to the south from the Kortelampi dam.
A secondary flow of around 1,000 cubic metres per hour of water would drain to the north, into the Oulujärvi waterway. This area already receives run-off of about 950 cubic metres, on top of all the waste water from normal operations.
In a northerly direction, the pumping of water is around 2,300 cubic metres per hour and water purity is monitored by regular sampling.
The mine’s management say waste water will be neutralised using limewater in the north and 20 percent proof sodium hydroxide in the south.
In total, the amount of extra waste water equates to around 4300 cubic metres per hour. Forty cubic metres is equal to around one fully loaded lorry of water almost twice per minute. Therefore, Talvivaara’s latest application relates to the release of over 107 lorry loads of additional water per hour.
Mass drainage justified by safety
Talvivaara operators are justifying the additional output of waste water by saying that they need to prevent excessive water accumulation during their bioleaching process. The company states that the mine does not have a large safety margin for storing extra water.
The extra outflow will increase stress on northern waterways for the entire month of August to the tune of some 130 kg of nickel and 1,500 tonnes of sulphate. In a southerly direction, water ways will bear an additional load of nearly 2,000 tons of sulphate and 210 pounds of nickel.
In the same announcement, the company says that the clean water will be subject to separate processing and management arrangements. The company has made control ditches for melt water that can be diverted from the mining area untreated.
The flow in a ditch bypassing Ylä-Lumijärvi will increase by 800 - 1000 cubic meters per hour. In addition, a ditch bypassing the Kortelampi dam will have a heavier flow as it passes Ylä-Lumijärvi.
ELY Centre request opinions
The Kainuu Centre for Economic Development, Transport and the Environment (ELY Centre) has asked various local Sotkamo and Kajaani environmental, chemical and government authorities, for advice pursuant to Article 62. A response is expected on Friday of this week.
Other requests were made for opinions on water treatment and management processes, especially as they relate to gypsum ponds and leakage, the environment of, and surrounding the mine area, stored water and wildlife management.