Protecting Our Natural Environment

Centerra is committed to environmental stewardship and to preventing, minimizing and mitigating the effects of our activities on land, water, air and biodiversity. Across our British Columbia sites, environmental management is integrated throughout the mine lifecycle, from exploration and operations through care and maintenance, closure and reclamation. Our approach combines regulatory compliance, site-specific monitoring, technical studies and engagement with Indigenous partners and local communities.

2025 British Columbia Environment Highlights

72 %

Of the water used at Mount Milligan was recycled

8

Tailings-storage-facility well pumps converted from diesel generation to electricity at Mount Milligan

2.5 ha

Disturbed area progressively reclaimed at Kemess through hydroseeding and hand seeding

Climate Change

Centerra continues to assess and advance opportunities to reduce energy use and greenhouse gas emissions. At Mount Milligan in 2025, a portable crusher was moved from diesel generation to grid electricity during warmer months, reducing diesel use by approximately 1,300 litres per day. Eight tailings-storage-facility well pumps were also operating on electricity, and a renewable diesel pilot confirmed no adverse impact on equipment performance.

British Columbia’s low-carbon electricity grid helps Mount Milligan reduce its reliance on diesel. Centerra also considers how climate change could affect its sites, including changes in water availability and looks for practical ways to reduce energy use and greenhouse gas emissions.

Waste, Hazardous Materials and Air Pollution

Centerra has site-specific rules for safely handling, storing, transporting, recycling and disposing of waste and hazardous materials, as well as responding to spills. Kemess and Endako produce relatively little waste while they are not operating, but waste and air quality continue to be monitored and managed.

Water Stewardship

Protecting water quality and reusing water are priorities at Centerra’s British Columbia sites. At Mount Milligan, much of the water used at the mine is recycled. Surface water, groundwater and water around the tailings facility are regularly monitored, along with fish and aquatic conditions. Water use at Kemess and Endako is limited, and water quality continues to be monitored at and around both sites.

Mine Closure and Reclamation

Planning for reclamation and eventual mine closure starts early and continues throughout the life of a mine. At Kemess, approximately 2.5 hectares were reclaimed using hand seeding and hydroseeding, which sprays a mixture of seed, mulch and water over disturbed ground. At Mount Milligan and Endako, Centerra is working with neighbouring First Nations to help shape how the land will be used and restored over the long term.

Biodiversity

Centerra’s approach is to avoid impacts on biodiversity where possible, then minimize, mitigate and compensate for remaining impacts, supported by site-specific monitoring and management programs. At Mount Milligan, wildlife and fish monitoring and updated soil-salvage practices support responsible land and water use. At Kemess, monitoring was expanded for bats, Barn Swallows and other wildlife.

Indigenous Knowledge is increasingly integrated into environmental stewardship. Nak’azdli Whut’en Land Guardians supported seed collection, soil analysis and wildlife monitoring connected with Mount Milligan, while Kemess continued to support regional wildlife research, including work with the Wild Sheep Society of BC.

Centerra first works to avoid impacts on plants, wildlife and habitat wherever possible. Where impacts cannot be avoided, the goal is to reduce and manage them. At Mount Milligan, this includes monitoring wildlife and fish and carefully storing soil for future reclamation. At Kemess, monitoring includes bats, Barn Swallows and other wildlife.

Indigenous Knowledge is increasingly integrated into environmental stewardship. In 2025, Nak’azdli Whut’en Land Guardians supported seed collection, soil analysis and wildlife monitoring connected with Mount Milligan, while Kemess continued to support regional wildlife research, including work with the Wild Sheep Society of BC.