Water Stewardship

Since one-third of the Ekati mine claim block is covered with water, water quality is an especially important part of the overall environmental monitoring program at the mine.

The amount of water that we can take from lakes and streams for road watering (for dust reduction) and to use in the accommodation areas is set out in the mine’s water licence, which is issued by the Wek’èezhìi Land and Water Board. The water licence also controls the quality of the processed water the company can return into the environment. The vast majority of water used at the mine (around 98%) is recycled from the Long Lake Containment Facility.

According to the current water licence, the Ekati mine must have two programs to monitor the quality of the water released from the Long Lake Containment Facility or King Pond Settling Facility into the downstream lakes: the Surveillance Network Program and the Aquatic Effects Monitoring Program. Runoff from the waste rock storage piles also requires monitoring. Monitoring of the receiving environment as a result of the Pigeon development was also required with the completion of the Pigeon Stream Diversion Channel (PSDC) and initiation of Pigeon pit development.

The Surveillance Network Program monitors the quality of water used for mining activities that is eventually released back into the environment. Scientists collect water samples from 22 sites identified in the water licence. If water from two discharge points does not meet the guidelines established by the water licence, it cannot be released into downstream lakes or used for road watering.

The Aquatic Effects Monitoring Program looks for changes in the aquatic environment downstream from the mine, such as slight increases in the levels of salts and metals, which could affect water quality or aquatic life. The program serves as an early warning system and allows us to address water quality changes before they become large enough to have a negative effect. This past year’s results are published in the 2016 Aquatic Effects Monitoring Program Summary Report posted on the Wek’èezhìi Land and Water Board website.

Carefully designed water quality management plans and monitoring programs are in place to identify changes to water quality after interacting with the rock piles, enabling the company to implement adaptive management.

Waste rock storage areas contain both waste rock and coarse kimberlite from the processing plant. Without a carefully designed management plan and monitoring programs, runoff may enter the environment through waste rock seepage. During 2016, scientists collected 41 samples from various areas. This was the first year the waste rock seepage survey was designed and conducted by Dominion personnel. Analyses of these samples indicated that waste rock seepage was not having a negative effect on the environment.