Categories
Monitoring

Mount Polley Environmental Monitoring

Environmental monitoring programs and closure research projects at Mount Polley mine site continue as planned. Remediation construction at the lower Hazeltine Creek and Edney Creek began this summer. Mount Polley staff, with assistance from Golder Associates Ltd., have begun development of the 2022 Water Management Plan.

Monitoring activities include regular water quality and toxicity sampling at:

  • water treatment plant (WTP) 
  • surface waters of Polley Lake, Bootjack Lake, Hazeltine Creek, Edney Creek & Quesnel Lake
  • mine contact waters including groundwater & mine seepage with flow rates

Regular inspections of all critical ditches, sumps, ponds, pumping systems and pipelines.

Ongoing surveys and studies include:

  • spawning activity in Hazeltine & Edney Creeks
  • remediated terrestrial habitats; vegetation growth, nesting sites and wildlife usage
  • aquatic habitats; fish population & tissue, zooplankton, phytoplankton, benthic invertebrates and sediments in Bootjack, Polley & Quesnel Lakes
  • dilution modelling of the Quesnel Lake discharge
  • semi-passive and passive water treatment options for closure which include a constructed wetland treatment system pilot study and a saturated rock fill bench scale test
Tour of aquatic habitat construction in lower Hazeltine Creek
Tour of aquatic habitat construction in lower Hazeltine Creek
Hazeltine Creek Reach One revegetated riparian area
Categories
Remediation

Experts recommend leaving tailings in Quesnel Lake

Lately we have received questions about the water quality at Quesnel Lake, so here are a few Q&A’s which address this subject.

First, what it means to conduct remediation?

According to the BC Environmental Management Act, “remediation” means action to eliminate, limit, correct, counteract, mitigate or remove any contaminant or the adverse effects on the environment or human health of any contaminant.

At Mount Polley, using the results of the detailed site investigations, and the human health and ecological risk assessments, the goal of the mine’s environmental remediation work is to repair and rehabilitate the areas impacted by the tailings spill such that they are on a path to self-sustaining ecological processes that result in productive and connected habitats for aquatic and terrestrial species.

As the impacts of the spill were determined to be primarily physical and not chemical, this has meant that the focus of the work has been on repairing and rebuilding habitats. 

Where can I find data about the water quality in Quesnel Lake?

The BC government website hosts an interactive map of surface water monitoring sites in the Province which gives access to results of water sampling and analyses, including Quesnel Lake and other surface water sites around the area of the mine. 

Why was the decision made to leave the tailings at the bottom of Quesnel Lake?

Research and monitoring of the physical and chemical stability of the tailings on the bottom of Quesnel Lake indicate that they are not causing pollution and studies of the bottom-dwelling (benthic) organisms have shown that they are slowly recolonizing the lake bottom as native sediment slowly deposits on top of the organic-poor tailings, bringing organic matter to the lake floor. 

After completing a Net Environmental Benefit (NEB) assessment, experts recommended that the best approach for remediation of the tailings in Quesnel Lake was to leave them alone and cause no further disturbance.

The experts determined that any attempt to remove the tailings could significantly disrupt the present ecosystem and set back the progress that had already occurred.

Remediation at Mount Polley is all about creating the conditions for successful natural recovery, and not doing more damage.