Emissions and environmental impacts are monitored in accordance with the approved programme

Terrafame’s mine has a detailed and comprehensive environmental monitoring programme approved by the supervisory authorities for the environment and the fishing industry, i.e. the Centres for Economic Development, Transport and the Environment of Kainuu, North Savo and Lapland. The purpose of this programme is to monitor the operations and emissions of the mine as well as the resulting environmental impacts. 

Emission monitoring covers monitoring of the mining process, discharge and sanitary waters of the mine and emissions into the air. Environmental impact monitoring covers the biological and physico-chemical monitoring of surface waters; groundwater, sediment and fishery monitoring; the biological monitoring of terrestrial ecosystems; and the monitoring of suspended dust, dust fallout, noise and vibration. Furthermore, the waste components produced in the production process are assessed.

In practice, monitoring is carried out by an external consulting company that uses individually certified samplers for collecting samples and an accredited environmental laboratory for analysing the samples. In addition to statutory monitoring, we implement our own environmental monitoring programme. This involves analysing the samples collected by Terrafame staff at the company’s laboratory.

Aerial emissions remained below permit limits

As part of the emission monitoring performed in 2016, aerial emission measurements covered the hydrogen sulphide levels of exhaust gases from the metals production plant. The limit for hydrogen sulphide levels decreed by the environmental permit is 50 milligrams per cubic metre (mg/m3). The hydrogen sulphide levels were clearly below the limit in 2016, as already in 2015.

Loading on water systems in Oulujoki and Vuoksi are monitored

As part of Terrafame’s statutory monitoring programme, the monitoring of discharged water covered concentrations in purified water as well as the environmental load resulting from the discharge of water. In 2016, water purified in accordance with the environmental permit was directed to the Nuasjärvi discharge pipe as well as the so-called old discharge routes, i.e. to River Kalliojoki and Lake Kolmisoppi, which form part of the Oulujoki watercourse area, as well as past Lake Ylä-Lumijärvi into the River Lumijoki, which form part of the Vuoksi watercourse area. In April–May 2016, Terrafame had to make additional discharges of purified water in order to ensure environmental and dam safety, in accordance with the notification filed to the Kainuu ELY Centre. The flow-weighted monthly averages of metal and sulphate concentrations in the water directed to the discharge pipe as well as to the old discharge routes remained below the limits detailed in the environmental permit.

In 2016, a total of approximately 7.1 million cubic metres of water was directed into the Nuasjärvi discharge pipe. In addition, 2.5 million cubic metres of water was directed to the old discharge routes. The concentrations in the discharge water remained clearly below the permit limits in 2016. The sulphate and sodium loading exceeded the quota of the old discharge routes, due to the additional discharges in the spring. The sulphate loading of the water discharged through the Nuasjärvi discharge pipe remained below the sulphate quota. The metals concentrations remained clearly within the annual quotas, both for the discharge pipe and the old discharge routes.

 

Loading
1 Jan - 31 Dec 2016
Time Discharged [m3] Copper [kg] Manganese [kg] Nickel [kg] Zinc [kg] Sulphate
[t]
Sodium
[t]
Old discharge routes 52/2013/1 in total   674,208 1.1 316.0 19.1 31.7 1300.0 264.3
South 1 Jan-9 Apr 269,930 0.5 152.8 8.2 17.5 512.0 91.8
North 1 Jan-9 Apr 404,278 0.6 163.2 10.9 14.2 788.0 172.5
Permit limit 52/2013/1     150 2,600 250 300 1,300 650
           
Discharge pipe (43/2015/1)
in total
1 Jan - 31 Dec 7,032,638 8,5 2,212,7 166 174,4 13,493.1 2,750.7
January 1 - 31 Jan 405,202 1.1 112.4 11.5 6.6 977.7 192.2
February 1 - 29 Feb 357,241 0.6 158.4 12.0 14.5 1,002.0 193.6
March 1 - 31 Mar 322,724 0.4 115.5 9.7 8.9 1,005.1 227.0  
April 1 - 27 Apr 500,132 0.5 324.6 17.2 22.9 999.8 205.6  
May 1 - 31 May 712,027 0.9 454.6 21.3 35.7 908.8 223.5  
June 1 - 30 Jun 729,654 0.7 170.8 14.3 11.5 893.8 219.4  
July 1 - 31 Jul 751,282 0.8 192.5 10.6 5.3 1,247.6 246.3  
August 1 - 31 Aug 748,878 0.7 97.2 11.5 7.1 1,225.1 263.8  
September 1 - 30 Sep 722,077 1.0 96.9 15.2 12.9 1,031.7 270.9  
October 1 - 31 Oct 736,182 0.7 123.8 16.0 20.3 1,524.4 260.4  
November 1 - 30 Nov 692,836 0.9 185.4 13.9 14.5 1,665.1 293.0  
December 1 - 31 Dec 354,403 0.2 180.6 12.5 14.2 1,012.0 155.0  
                 
52/2013/1 and 43/2015/1 in total   7,706,846 9.6 2,528.7 184.8 206.1 14,793.1 3,015.0  
                 
  Time Discharged [m3] Copper
[kg]
Manganese
[kg]
Nickel [kg] Zinc [kg] Sulphate
[t]
Natrium
[t]
 
Additional discharge in spring 2016
in total
  1,910,796 6.5 1,580.7 111.0 190.2 2,753.9 687.9  
South 9 Apr - 6 May 732,480 4.4 1,024.8 84.0 161.4 1,025.2 268.6  
North 9 Apr - 6 May 1,096,123 2.0 479.5 23.4 21.4 1,580.8 650.7  
Old discharge routes in total   1,828,603 6.4 1,504.2 107.4 182.7 2,605.9 919.3  
Discharge pipe 27 Apr - 30 Apr 82,193 0.1 76.4 3.6 7.5 147.9 2,783.6  
                 
TOTAL in 2016
(1 Jan - 31 Dec)
  9,617,642 16.1 4,109.5 295.7 396.4 17,547.1 3,702.9  
South 1 Jan - 6 May 1,002,410 4.9 1,177.5 92.2 178.8 1,537.1 268.6  
North (without discharge pipe) 1 Jan - 6 May 1,500,401 2.5 642.7 34.3 35.6 2,368.8 650.7  
Old discharge routes in total   2,502,811 7.5 1,820.2 126.5 214.4 3,905.9 919.3  
Discharge pipe 1 Jan - 31 Dec 7,114,831 8.7 2,289.3 169.2 182.0 13,641.2 2,783.6  
           

 

Figure 1: Loading on water bodies resulting from the mine's operations in 2016.

The condition of water bodies is constantly monitored

In 2016, no significant changes were observed in water quality along the water discharge routes in the direction of River Oulujoki, compared to the previous year. The results are based on surface water monitoring, which is part of environmental impact monitoring.

In nearby water bodies (Salminen, Salmisenpuro, Kalliojärvi, Härkäpuro, Kuusijoki, Kalliojoki, Kolmisoppi, Tuhkajoki), the impacts of water discharged from the mine include higher electrical conductivity and sulphate concentrations compared to natural water bodies, particularly in water layers near the bottom where concentrations were higher than in the surface layer. Lake Salminen has been permanently stratified since 2011, and no signs of destratification have been observed. Lake Kalliojärvi also continues to be permanently stratified. Meanwhile, the water masses in Lake Kolmisoppi mixed during the spring and autumn circulation periods.

Loading has also been observed in Lake Jormasjärvi, where sulphate concentrations were found to be higher than the levels typical for the area. However, seasonal circulation continues to occur quite normally. Sulphate concentrations in the River Jormasjoki are higher than the levels typical for the area. The sulphate loading on Nuasjärvi through Jormasjoki in 2016 decreased from the previous year. The sulphate loading on Nuasjärvi through Jormasjoki will decrease in the coming years as the sulphate loading directed to old routes has decreased and will continue to decrease from the current level.

Figure 2: The sulphate loading from the mine on Lake Nuasjärvi, through Jormasjoki, in 2009–2016.

The impacts of water run through the discharge pipe into Lake Nuasjärvi have also been monitored through statutory monitoring performed by an external expert body. During 2016, samples were collected from depressions in Lake Nuasjärvi at an increased rate.

In the depressions closest to the discharge pipe, the sulphate level was found to be approximately 100 milligrams per litre (mg/l) during the winter. In May–June, the sulphate concentration was found to have increased in a minor depression (Selkäsaari depression) to 200 mg/l, which corresponds to the estimates presented in the environmental permit application for the discharge pipe. Similar sulphate concentrations were observed in a depression in Lake Nuasjärvi before the discharge of mine waters into the lake began (Figure 3). Based on the analysis results, spring circulation mixed the waters in the depressions of Lake Nuasjärvi, excluding areas of more than 20 metres deep in the Selkäsaari depression. Autumn circulation was completed in September–October in the entire Lake Nuasjärvi when water overturned in the Selkäsaari depression as well.

The metal concentrations of Lake Nuasjärvi have been low also in depressions close to the discharge pipe. For instance, the nickel concentration has clearly decreased during the last 10 years, and the same development has continued during use of the discharge pipe.

Figure 3: Water pH in the depression near the Lake Nuasjärvi discharge pipe (Nj 23).

Figure 4: Water conductivity in the depression near the Lake Nuasjärvi discharge pipe (Nj 23).

Figure 5: Water sulphate concentration in the depression near the Lake Nuasjärvi discharge pipe (Nj 23).

Figure 6: Water nickel concentration in the depression near the Lake Nuasjärvi discharge pipe (Nj 23).