‘ World’s richest’ wild trout stream threatened by acid rock damage

Okanagan Connector the source of an acidic slew of toxic metals emptying into the headwaters of Pennask Creek

Dignitaries described the $ 225- million Okanagan Connector, Highway 97C, as an important new conduit for commercial and industrial activity when it officially opened in 1990.

What they didn’t say — or know — is that for decades to come the highway would become the source of an acidic stew of toxic metals emptying into the headwaters of Pennask Creek, described as the world’s greatest spawning site for wild rainbow trout.

It is so rich that one million eggs are taken from trout in the creek each spring and reared in hatcheries, then used to stock some 110 lakes around the province — more than any other single source.

The province has already spent millions to reduce the environmental impact — helping to ensure a healthy spawn downstream of 25,000 trout in 2013 — but acknowledges that current remediation is falling short and more needs to be done.

“( Pennask Creek is) the cornerstone of the B. C. lake- stocking program,” confirmed Tim Yesaki, vice- president of operations with the Freshwater Fisheries Society of B. C., which collects the Pennask trout eggs for restocking lakes across B. C.

When construction crews began to build the Okanagan Connector, they unwittingly exposed pyrite- bearing rocks near Pennask Summit to air and water, thereby triggering the process of acid- rock drainage, or ARD.

ARD poses a threat to fish and aquatic life through acidification of the water and elevated concentrations of sulphate and metals such as iron, zinc, cadmium, copper, and aluminum.

The problem is more commonly associated with mine sites.

The best- known local example is Britannia copper mine, a national historic site on the Sea to Sky Highway where a $ 27- million treatment plant officially opened in 2006. Under a public- private partnership, EPCOR Water Treatment Services built the plant and in 2012 received $ 720,000 in operating costs from the province. It has been so successful that pink salmon now spawn there.

The B. C. government told The Vancouver Sun it is aware of water- treatment systems installed, or about to be installed, at 13 other mine sites ( all but two closed) across the province. The costs of these operations are borne by the mining companies.

Acid rock drainage on the Okanagan Connector could not have occurred at a worse site — draining into so- called Highway Creek, a tributary of Pennask Creek, which flows into Pennask Lake.

Pennask Creek is a 1,245- hectare provincial protected area created in 2001 to protect an internationally significant rainbow trout brood fishery. A highways district manager at the time described the creek as “the richest rainbow trout spawning creek in the world.”

Today, the Ministry of Forests, Lands, and Natural Resource Operations, describes the creek thus: “The Pennask rainbow trout run is one of the largest — if not the largest — of its kind in the world.”

The province has discovered that polluting a creek with those sorts of credentials doesn’t come cheap.

In 2005, the Ministry of Transportation pleaded guilty to two federal Fisheries Act counts of depositing a deleterious substance into Pennask Creek.

Elevated levels of aluminum, copper and zinc were found.

The province was fined $ 1,000 and ordered to pay $ 45,000 to the Environmental Damages Fund for use in creek rehabilitation.

In response, the province installed a treatment system consisting of two acid- mine drainage machines to raise pH levels ( neutralizing acid levels) and remove metals, constructed lined channels and reservoirs to capture water and then treat it with lime, and drilled monitoring wells to provide waterquality information.

To date, the government has spent $ 4 million on mitigation measures, with more to come.

Transportation ministry spokeswoman Kate Trotter said the province recently hired Golder Associates on a $ 150,000 contract to offer expertise in acid- rock drainage and metal leachate and to develop a more permanent plan for the site.

The ministry continues to “research long- term solution options,” appreciating it can take a “very long time” for acid rain drainage to naturally diminish and that “we are committed to long- term maintenance of the site,” Trotter said.

The action follows a November 2011 report by consultants CH2M HILL Canada that concluded “mitigation measures at Pennask Creek have not produced the desired results in terms of reducing acid rock and metal concentration impacts to aquatic life.”

Despite serious ongoing concerns, the creek had an excellent spawn of upwards of 25,000 trout this past spring, suggesting that acid rock drainage in the headwaters — so far, at least — has not compromised the overall productivity of the run farther downstream.