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
Community Remediation

Mount Polley built and managed an on-site fish hatchery in 2018

After the spill, a population monitoring program on Polley Lake indicated there had probably been a reduction in the age class of the population of Rainbow Trout (as upper Hazeltine Creek was the main spawning area for these trout). There was spawning observed in Frypan Creek at the north end of Polley Lake, however it was noted to be a much smaller habitat. The Mount Polley Environmental Team (MPET) recognized it was important to allow the fish to spawn in Hazeltine Creek, but the Habitat Remediation Working Group (HRWG) had concerns whether the spawn in the reconstructed Hazeltine Creek would be successful.

The MPET developed a backup plan. With guidance provided by Minnow Environmental and David Petkovich (Aqua-culturist), over 11,000 Rainbow Trout fry were raised in an on-site fish hatchery in spring 2018. Eggs were harvested and fertilized from some of the local Rainbow Trout that had returned to upper Hazeltine Creek to spawn.

The fertilized eggs were incubated in trays so temperature, flow and dissolved oxygen levels could be regularly monitored. Water intake was sourced from below the thermocline in Polley Lake in order to maintain cooler water temperatures.

Egg trays in Mount Polley on-site Rainbow Trout hatchery [2018]
Egg trays in Mount Polley on-site Rainbow Trout hatchery [2018]

Within two months, the eggs hatched into alevins (yolk-sac fry) and within another two weeks the yolk sacs were completely absorbed.  Throughout the incubation stage the eggs were counted, and unfertilized eggs removed.

Fish tray showing Rainbow Trout eggs hatching [June 2018]
Fish tray showing Rainbow Trout eggs hatching [June 2018]
Rainbow Trout fry in shallow ponding tanks [early July 2018]
Rainbow Trout fry in shallow ponding tanks [early July 2018]

The fry were then transferred from the incubation trays to shallow rearing tanks. When the fish reached their target biomass, they were transferred into deeper rearing tanks, and from there released into the Polley Lake watershed.

Mount Polley hatchery rearing tanks. [summer 2018]
Mount Polley hatchery rearing tanks. [summer 2018]

The MPET and Minnow Environmental released over 11,100 Rainbow trout fry from the hatchery into Polley Lake on September 25 and 26, 2018. The adipose fins from each fry were clipped as a means of tagging (identification). On the second day, students, parents and a teacher from Columneetza Middle School’s Greenologists / Enviro Club based in Williams Lake assisted with the Rainbow Trout fry release

Mount Polley strongly encourages Polley Lake fishers to report if they catch fish with a clipped adipose fin to gabe.holmes@mountpolley.com. This will help the MPET determine how successfully the hatchery trout are surviving. Thank you!

Categories
Remediation

Rainbow trout return to Hazeltine Creek

In 2018 a milestone was celebrated by the Mount Polley Environmental Team (MPET) when the efforts of the remediation work rebuilding Hazeltine Creek witnessed the return of Rainbow Trout, Redside Shiners and Long Nose Suckers to the rebuilt part of the creek.

After the August 2014 tailings spill, fish from Polley Lake were prevented from entering Hazeltine Creek by fish fences above the Polley Lake Weir, while the habitat underwent reconstruction. During the winter of 2014-2015, the creek channel was cleaned up, tailings and debris removed, and a new Hazeltine Creek channel was built and rocked-in.

Fish fences blocking passage from Polley Lake (top left) into upper Hazeltine Creek [2015]
Fish fences blocking passage from Polley Lake (top left) into upper Hazeltine Creek [2015]

In April 2015, the Habitat Remediation Working Group (HRWG*), including the T’exelc First Nation (Williams Lake First Nation) and Xatśūll First Nation (Soda Creek Indian Band) and their consultants, and Mount Polley Mining Corporation (MPMC) representatives and their consultants (Envirowest and Golder), began discussing options for constructing new fish habitat in upper Hazeltine Creek, and requirements MPMC would need to meet in order for fish to be allowed to return to the creek.

*HRWG also includes representatives of the federal Department of Fisheries and Oceans, the provincial Ministry of Environment, and the provincial Ministry of Forest Lands and Natural Resource Operations, both water stewardship and fisheries sections.

Mount Polley employees, consultants, contractors, First Nations and community partners began ecological remediation work on Hazeltine Creek in 2015. By May 2015 the water in Hazeltine was running clear, and the bugs (invertebrates that provide food for fish) were starting to grow in the creek, so it was decided that the installation of new fish habitat could begin and this work started in 2016.

HRWG members looked at historical records to determine what the local conditions were before the spill, and remediation planning was based on that information. The planning was also constrained by the configuration of the constructed rocked-in channel. The group agreed to a field fit approach for the remediation. Conceptual designs were developed by Mount Polley and their consultants, and the plans were reviewed by the HRWG.  

The design approach was to naturalize the rocked-in channel by adding sinuosity (curves and bends), building a sequence of pools, riffles and weirs, and installing boulders, large woody debris and gravel at the bottom of the creek, to provide appropriate spawning and rearing habitat for the fish known to have used upper Hazeltine Creek before the spill, particularly Rainbow Trout, an important species in Polley Lake.

Abundant Rainbow Trout observed upstream of fish fences, looking to transit into Hazeltine Creek from Polley Lake to spawn. [May 2017]
Abundant Rainbow Trout observed upstream of fish fences, looking to transit into Hazeltine Creek from Polley Lake to spawn. [May 2017]

After two years of habitat construction (2016-2017) approximately 2.5 km of spawning and rearing habitat was completed in the upper part of Hazeltine creek from the outlet of Polley Lake to the Gavin Lake Road Bridge. In late 2017, the MPET believed conditions were right to let the fish back into the creek. There was habitat, flowing water, and food, and the water quality met aquatic guidelines.

In December 2017, the HRWG began detailed discussions on the approach to allowing the Rainbow Trout back into Hazeltine Creek. Discussion included requirements for fish monitoring, water quality, sediment quality, habitat quality and quantity, Polley Lake access and egress etc, and the permits and licenses that Mount Polley would have to apply for and comply with from the Ministry of Forests, Lands, Natural Resource Operations and Rural Development Water Stewardship Group.

In March 2018, new fish fences were installed in Hazeltine Creek approximately 2.6 km from the outlet of Polley Lake to prevent fish from going further downstream than the area where habitat reconstruction have been completed. On April 26, 2018, the fish fences at the outlet of Polley Lake to Hazeltine Creek were removed and the Rainbow Trout once again had access to the first 2.6 km of upper Hazeltine Creek.

Note:  the lower part of Hazeltine Creek includes a steep rock canyon that is a natural barrier preventing Quesnel Lake fish from entering middle and upper Hazeltine Creek and Polley Lake. However, in the natural creek system, fish from Polley Lake can be swept down the creek into Quesnel Lake once all the fish habitat reconstruction is completed and fish fences are removed.

In addition to ingress into Hazeltine Creek, the fish also needed to be able to return to Polley Lake. This required that a fishway (ladder) be built for the fish to bypass the Polley Lake Weir water control structure. An engineered fishway was installed by Mount Polley maintenance staff at the Polley Lake weir and the flows are monitored to properly maintain water levels for fish passage.  The fishway was designed so the flow can be adapted to seasonal changes.

Mount Polley fishway ladder
Mount Polley fishway ladder

Fish monitoring was intense in 2018.  MPET worked with Minnow Environmental conducting weekly surveys of the fish populations to track the 2018 spawn and fish activity. The surveys included counting fish at established monitoring stations and pools, and observing how the fish used the creek (i.e. seeking shelter under woody debris or behind boulders). Temperature data and dissolved oxygen levels were also monitored in Hazeltine Creek.

Results of the 2018 Hazeltine Creek fish re-introduction were very impressive. Fish monitors estimated almost 5,000 Rainbow Trout accessed the creek to spawn in spring 2018.  The spawn was successful. A spawning survey in July 2018 observed over 18,600 Rainbow Trout in upper Hazeltine Creek, the majority being from the 2018 spawn.

Spawning rainbow trout in Hazeltine Creek. [late May 2018]
Spawning rainbow trout in Hazeltine Creek. [late May 2018]
Categories
Mining facts

Likely Area Mining History

The area around Likely has a long and fascinating history of placer mining. Placer mining refers to mining materials (mostly gold) deposited in ancient stream beds that are still largely unconsolidated (i.e. relatively loose materials).

Some of the earliest gold discoveries in the area were made in 1859, one in the Horsefly River, and one in the Dancing Bill Gulch. The latter became known as the China Pit and then the Bullion Pit, and is located just downstream of Likely on the west side of the Quesnel River. The Bullion Pit is now a local historic site with a public walking trail.

Quesnel Forks information sign at the entrance to the historic townsite

Placer gold was also discovered near the mouth of Keithley Creek on the Cariboo River about 12 km upstream from Quesnel Forks in July 1860. Other significant discoveries were subsequently made just 4 km south of Likely on Cedar Creek, and in Quesnel River itself.

In 1897, the Golden River Canal Co. decided to build a dam across the Quesnel River at the outlet from Quesnel Lake in order to block the river and be able to work the gravels from the bottom of the river. The tent town that developed on the site was known as ‘Quesnel Dam’. In 1920, the dam was dynamited and the remnants of the dam can be seen just north of the Likely Bridge in Likely. After the removal of the dam, the residents decided to rename the town ‘Likely’ after a local prospector, John Likely.

Drone image of the Bullion Pit near Likely, BC

The Bullion Pit ulimately became a very significant gold producer in the area. BC Minfile report number 093A 025 states that “In 1897, the Consolidated Hydraulic Mining Company commenced full scale operations and between 1898 and 1902, the company processed 5,912,700 cubic metres of mixed materials, recovering 1,402,316 grams of gold at a recoverable grade of 0.132 grams per tonne gold… Estimations indicate that a total of 200 million tonnes of material were removed by hydraulic methods and 5.463 million grams (175,644 ounces) of gold were produced.” Indications are that much of this material was discharged directly into the Quesnel River.

Polley Lake Outlet Structure: water works for placer mining — early 1900s. Courtesy of BC Archives.

The shortage of water in the early 1900s led the operators of the Bullion Pit to construct a number of water control and diversion works on local streams and lakes to gather water for the hydraulic operations at the pit. Photos from the BC archives, including ones featured in the TV program “Gold Trails and Ghost Towns – The Bullion Pit episode”, document weirs and diversion ditches built on Polley Lake and Hazeltine Creek and other creeks in the area.

To learn more about Likely’s mining history, visit the Cedar City Museum and Info Center located in the Cedar Point Provincial Park in Likely, BC.

This Facebook page gives regular updates on the areas in BC that were part of the mine’s early gold mining history.

Historic building in Quesnel Forks

Many placer mines continue to operate in the area around Likely, including near Quesnel Forks. Quesnel Forks is a restored ghost town located 12 km outside of Likely with a rich mining history and is also worth a visit. It is situated at the point where Cariboo River meets the Quesnel River, and features a beautiful campground and a number of restored and partially restored old buildings.

Historic building in Quesnel Forks. Courtesy of Mount Polley
Historic building in Quesnel Forks overlooking Quesnel River. Part of the history of the Mount Polley site and surrounding area.
View of Quesnel River at confluence with Cariboo River from Quesnel Forks historic townsite
View of Quensel River from Quesnel Forks historic townsite.
Cedar City Museum and information centre in Cedar Point Provincial Park in Likely, BC on Quesnel Lake.
Historic mining equipment on display in Cedar Point Provincial Park in Likely, BC
Categories
Remediation

Mount Polley water quality is evidence of remediation

Mount Polley takes water quality very seriously. Extensive monitoring is evidencing the effectiveness of the remediation and site water management programs undertaken by Mount Polley.

How is water quality monitored in Polley and Quesnel Lakes to ensure proper environmental monitoring is being carried out?

  • Mount Polley follows the BC-ENV approved Comprehensive Environmental Monitoring Plan. The results for all our monitoring sites are published in the publicly available Annual Environmental and Reclamation Reports.
  • You can find a link to the current report here: 2019 Environmental Report 
  • Polley Lake water met all BC Water Quality Guidelines for aquatic life parameters in 2019 with the exception of phosphorus, which was elevated even prior to mining. As Polley Lake is immediately adjacent to the mine site, this indicates the mine is doing a very good job of capturing and controlling run-off.
  • A number of sites are monitored in Quesnel Lake, and in 2019 there were no exceedances of acute BC Water Quality Guidelines.
  • At one monitoring site in Quesnel Lake, there was one minor copper exceedance of chronic BC Water Quality Guidelines in 2019, but as copper is also naturally occurring in the native soils and sediments around Quesnel Lake, and there are a number of creeks that empty into the lake near this sample site, it is difficult to know if this exceedance was natural or related to the mine.

We often get asked if we continue to discharge into Polley Lake or Quesnel Lake?

The mine discharges mine site water, that meets strict permit limits, through diffusers at depth into Quesnel Lake. This water is the only substance the mine is discharging to Quesnel Lake. The mine does not discharge water into Polley Lake.

  • Mount Polley discharges only mine site water that meets strict Environmental Management Act (EMA) permit guidelines.
  • treated by a water treatment plant, when needed to meet permit requirements, before being released into Quesnel Lake. The water going into the treatment plant (influent) is monitored on an ongoing basis, and the treated water leaving the plant (effluent) is sampled regularly for analysis. Not all water at Mount Polley requires treatment to meet EMA permit water quality guidelines before discharge, and in the past, water that was simply stored in Springer Pit was found suitable for passive discharge.
  • The lake water quality is also routinely monitored and sampled regularly as part of the mine’s Comprehensive Environmental Monitoring Plan.

Continued monitoring data confirm that remediation efforts are effective.

  • Currently, there are no indications in the monitoring data that the water discharged from Mount Polley is having any negative effects on Quesnel Lake water quality or aquatic life.
  • If you are interested in looking at water quality data collected on surface water in the area around the Mount Polley mine, in addition to data in the mine’s annual reports, results are available through the BC Government Surface Water Monitoring Sites Interactive Map.