Transboundary Mining Threats to Washington State: the Similkameen River

Transboundary Mining Threats to Washington State: the Similkameen River

Conservation Northwest / Feb 19, 2021 / Healthy Watersheds, Legislation, Protecting Wildlands

Washington must demand action from British Columbia on mining regulatory reform before it’s too late.


DOWNLOAD OUR 2021 fact sheet (PDF) OR watch THIS new VIDEO about threats to the similkameen river from Copper Mountain Mine. Then TAKE ACTION!


The Similkameen River is part of a transboundary watershed which drains the northeastern slopes of the Cascade Mountains into north-central Washington state, flowing over Enloe Dam before merging with the Okanogan River near the border town of Oroville, and then, further downstream, joining the Columbia River near Brewster, Washington.

Similkameen River in fall. Photo Jessica Kelley

A legacy of mining development in British Columbia has already deteriorated the Similkameen River, yet proposals to greatly expand the Copper Mountain Mine and other extractive industrial developments threaten this transboundary watershed, Canadian First Nations, U.S. tribes and residents who live there, and fish and wildlife, including Endangered Species Act listed Chinook salmon and steelhead that return each year.

Washington State must demand action from British Columbia on mining regulatory reform before it is too late.

Join us in taking action by contacting lawmakers!

A Legacy of Mining and Deteriorating Water Quality

The Similkameen sub-watershed, located primarily in south-central British Columbia (B.C.), has a legacy of mining development in its headwaters. Three different mining facilities already pollute the upper Similkameen watershed. This is in addition to over 50 abandoned mines leaching pollution into the watershed. For years, British Columbia First Nations have raised concerns about mining and threats to water.

As a result of these mining operations, water quality on the upper Similkameen and particularly its tributaries is trending downward due to sulfate, nitrate, selenium, arsenic, cobalt, and other toxic pollutants. Water quality on tributaries that feed the Similkameen around the location of these mining operations is negatively affected due to historical and present activities. Standards for drinking water and aquatic life for certain pollutants in the B.C. portion exceed provincial standards. Of particular concern are high levels of arsenic likely from a legacy of mining in the upper Similkameen watershed, between Hedley, B.C. and the Washington/B.C. border that exceed federal United States EPA guidelines.

Copper Mountain Mine: Violations and Proposed Expansion

One mine in particular, Copper Mountain, is a growing concern to communities in Washington state. Copper Mountain is located 62 miles upstream of the international border and presents a significant number of compliance issues and pollution violations, despite numerous orders and warnings from inspectors.

Since 2011, the B.C. provincial government has issued as many as 40 different instances of non-compliance many of which are related to unauthorized discharges of pollution to the Similkameen River watershed. The pollution from the mine had been flowing non-stop into the river for well over a year despite orders from the province to prevent the discharge from flowing into the environment. In November, the mine owner received two major fines in the amount of $52,000 for failing to control pollution flowing into the river.

The Copper Mountain Mine in the transboundary Similkameen Watershed threatens the waters that flow into the Columbia River and surrounding communities downstream.

What about the chance of tailings dam disaster at Copper Mountain?

The planned mega expansion at Copper Mountain will make things worse and increase the likelihood of increased transboundary pollution, as well as possibly increase the chance of a catastrophic tailings dam failure.

If the tailings dam is raised to a height of 853 ft, it will be taller than the Seattle Space Needle, which is 605 ft.

To make matters worse, the owners of Copper Mountain are moving to expand the operations, increasing production by 70 percent and raising the current tailings management facility by a staggering 360 feet, a 73 percent increase over the current height. Moreover, the mine operator has posted a paltry bond of $7,040,000 which is far less than what is needed to cover the true costs of long-term monitoring, reclamation, recovery, and restoration of the environment following closure of the mine.

BC’s own expert panel predicts that there will be two tailings pond failures every ten years, and six every thirty years. A tailings dam failure at British Columbia’s Mount Polley mine, in 2014, was the worst environmental disaster in BC history. While that disaster did not directly affect Washington State, it would be foolish to assume that a similar disaster could never happen in a transboundary watershed, such as the Similkameen.

Due to a lack of financial assurance requirements under B.C. mining law, operators of the Mount Polley mine were never held responsible. Affected interests were never compensated. Even more sobering, the Mount Polley dam that breached was slightly over 140 feet high. One can only imagine the downstream devastation that would occur if a 800 plus-foot high dam on the transboundary Similkameen were to fail.

Washington Leaders Must Demand Action

Washington state needs to take seriously the risks posed to downstream Washington interests in the Similkameen watershed, as well as other transboundary rivers such as the Upper Skagit, Kettle and Upper Columbia watersheds.

The Similkameen River is vital to the Upper and Lower Similkameen Indian Bands and other B.C. First Nations, as well as Washington’s Colville Confederated Tribes. This river must be protected from mining pollution. British Columbia must enact protections to protect transboundary rivers like the Similkameen and prevent disasters. These protections must extend to all of the Upper Columbia and all transboundary rivers shared with Canada.

Now is the time for Washington state leaders including the Governor, State Legislators and Tribal Governments to speak up and take action before a disaster like Mount Polley strikes, sending toxic mine pollution downstream and across the international border.

You can use our easy action form to send a message to state legislators and Governor Inslee, or read suggested comments on this webpage.

LEARN MORE IN THIS VIDEO, then TAKE ACTION on british columbia mines today!