Material Topic: Water

303–1  Interaction with water as a shared resource

Water conservation is an important part of Boliden’s policy. Reduction of water use has a high prioritywithout, however, compromising on safety and environmental responsibility. Each Boliden site must assess their water system at least biannually and perform a water risk evaluation.

303–2  Management of water discharge-related impacts

In mining, water is typically used in mineral processing and slurry transport, while in smelting, it is used for cooling and gas cleaning purposes. Boliden’s operations do not re-use water from other organizations, but in Harjavalta and Kokkola, waste water from adjacent operations is ducted into Boliden’s waste water treatment plants for treatment before being discharged to recipients. These volumes are not reported to Boliden. All other water volumes are based on data from flow meters.

Water recycled and reused (million m³)

2016

2017

2018

       

Recycled volume

110

106

107

Percentage of water recycled

78%

73%

74%

303–3  Water withdrawal

The water volumes are measured and/or calculated for each site by the use of flow meters and/or the monitoring of pump operating data.

Total water withdrawal by source (million m³)

2016

2017

2018

       

Surface water (sea)

80

81

80

Surface water (inland)

40

44

46

Ground water

17

17

16

Collected rain water

1

1

1

Municipal water

2

2

2

Total water withdrawal

140

145

145

303–4  Water discharge

Discharges to water derive from dams and tailings ponds at the mines, and from water treatment plants and collection of surface water at smelters and mines. Boliden’s smelters account for approximately 70% of metal discharges to water while the mines account for the remaining 30%. Boliden’s mines account for approximately 80% of the Group’s nitrogen discharges with the nitrogen generated mainly from the use of explosives and their handling. The remaining 20% comes mainly from wastewater recycling at the Kokkola smelter.

Ensuring efficient and stable operations at water treatment plants and recirculating the process water as much as possible are important parts of reducing discharges to water. Boliden’s operations include purifying process water as well as a significant amount of the rainwater that falls within the industrial areas. In recent years, there has been heavy rainfall, underlining the need for increasing the water treatment capacity, and several of Boliden’s operations have consequently implemented measures to meet this need.

In total the discharge of metals and nitrogen to water from Boliden’s units decreased in 2018 due to improved water management and control, and the nitrogen treatment plants taken into operation. There was a slight increase during the middle of the year that was mainly due to increased operations.

The management and monitoring of water consumption has also been improved due to the decision that all Boliden’s units shall have a Water Management Plan.

Once the water-cleaning processes are completed, the smelters discharge their water to the sea while the mines discharge the water into rivers and lakes. The water discharged to recipients is monitored to ensure that levels of pollutants are within the quality standards stipulated in the environmental permit. Accredited laboratories, both internal and external, are used for analyses of samples taken on site. Metal discharges to water from Smelters have been stable during 2018, and well below both target and budget.

Water discharge

2016

2017

2018

       

Metal discharges to water, tonnes (me-eq)

13

9

8

Metal discharges to water, tonnes (mass)

22

15

14

Nitrogen /N-tot/ to water tonnes (mass)

300

236

240

Discharged water volume (million m3)

2016

2017

2018

       

To wetland

0

0

0

To inland surface water

64

57

55

To sea surface water

62

71

78

To municipal treatment plants

0.03

0.03

0.03

Total

126

128

133

303–5  Water consumption

The water consumption of Boliden is calculated from the difference between the total water withdrawal and the discharged water volume of Boliden’s sites.

Water consumption (million m³)

2016

2017

2018

       

Total water withdrawal

140

145

145

Discharged water volume

126

128

133

Water consumption

14

17

12