Skip to main content

How Gold Mining Can Affect Water Quality

There are several ways in which gold mining can affect water quality. Some of the following information is taken from the Safe Drinking Water Foundation online article, “Mining and Water Pollution.” Local photos are displayed, pertaining to Buckhorn Mountain and the associated facilities.

Introduction

A stream feeding the Nine Acre Wetland, located near the Buckhorn mining operation

Water is essential to life on our planet. A prerequisite of sustainable development must be to ensure uncontaminated streams, rivers, lakes and oceans.

Mining affects fresh water through heavy use of water in processing ore, and through water pollution from discharged mine effluent and seepage from tailings and waste rock impoundments. Increasingly, human activities such as mining threaten the water sources on which we all depend. Water has been called “mining’s most common casualty” (James Lyon, interview, Mineral Policy Center, Washington DC). There is growing awareness of the environmental legacy of mining activities that have been undertaken with little concern for the environment. The price we have paid for our everyday use of minerals has sometimes been very high. Mining by its nature consumes, diverts and can seriously pollute water resources.

Negative Impacts

While there have been improvements to mining practices in recent years, significant environmental risks remain. Negative impacts can vary from the sedimentation caused by poorly built roads during exploration through to the sediment, and disturbance of water during mine construction. Water pollution from mine waste rock and tailings may need to be managed for decades, if not centuries, after closure. These impacts depend on a variety of factors, such as the sensitivity of local terrain, the composition of minerals being mined, the type of technology employed, the skill, knowledge and environmental commitment of the company, and finally, our ability to monitor and enforce compliance with environmental regulations. One of the problems is that mining has become more mechanized and therefore able to handle more rock and ore material than ever before. Therefore, mine waste has multiplied enormously. As mine technologies are developed to make it more profitable to mine low grade ore, even more waste will be generated in the future.

Waste from the Mining Process

Ore is mineralized rock containing a valued metal such as gold…The ore is crushed into finely ground tailings for processing with various chemicals and separating processes to extract the final product.

Kettle River facilities

Types of Water Pollution from Mining

  • Acid Mine Drainage
    • Many of the metals being mined in North America, including the gold mined from Buckhorn, tend to be found in rock that contains sulfide minerals. When ore and surrounding rock are excavated during mining, the sulfides become exposed to water and air, and may form sulfuric acid. This acid in turn leaches metals and other substances from the rocks that can harm ecosystems. The acid will leach from the rock as long as its source rock is exposed to air and water and until the sulphides are leached out – a process that can last hundreds, even thousands of years. Acid is carried off the minesite by rainwater or surface drainage and deposited into nearby streams, rivers, lakes and groundwater. Acid mine drainage is considered one of the most serious environmental threats posed by mining, and it can devastate aquatic resources for generations.
  • Heavy Metal Contamination & Leaching
    • Heavy metal pollution is caused when such metals as arsenic, cobalt, copper, cadmium, lead, silver and zinc contained in excavated rock or exposed in an underground mine come in contact with water. Metals are leached out and carried downstream as water washes over the rock surface. Although metals can become mobile in neutral pH conditions, leaching is particularly accelerated in the low pH conditions such as are created by Acid Mine Drainage.
  • Processing Chemicals Pollution
    • This kind of pollution occurs when chemical agents (such as cyanide or sulphuric acid used by mining companies to separate the target mineral from the ore) spill, leak, or leach from the mine site into nearby water bodies. These chemicals can be highly toxic to humans and wildlife.
  • Erosion and Sedimentation
    • Mineral development disturbs soil and rock in the course of constructing and maintaining roads, open pits, and waste impoundments. In the absence of adequate prevention and control strategies, erosion of the exposed earth may carry substantial amounts of sediment into streams, rivers and lakes. Excessive sediment can clog riverbeds and smother watershed vegetation, wildlife habitat and aquatic organisms.
Drillpad exploration

Water Quantity

Mining can deplete surface and groundwater supplies. Groundwater withdrawals may damage or destroy streamside habitat many miles from the actual mine site. [end quote from the Mining and Water Pollution article]

Tonasket Outreach School

Each spring since 2016, students from the Tonasket Outreach Program have been invited to participate in Triple Creek restoration project. During the first field trip, a group of 23 students of all ages, and six adult volunteers came out to the site and helped with planting trees and shrubs, building perches for birds of prey, taking photos to monitor the site, and participating in educational activities that illustrated the connections between producers and consumers in the web of life.

Participation at Triple Creek offers a bounty of ongoing learning experiences for the students of Outreach. Their classroom teacher, Sonja, has been leading students in research on riparian buffer zones. Grades 3-6 have been learning about photo monitoring, and helping to organize documentation of the project. They have also been able to celebrate the return of beaver to the creek! There will be a variety of opportunities for students of all ages to be involved throughout the school year, culminating in a return field trip in the spring. At that time students observe major changes that have occurred in the stream since their previous visit. They will see the instream structures that OHA and our team have constructed, and the ways in which these structures have mimicked beaver dams.

In 2019, the Outreach students are merging music and science with OHA’s Conservation Coordinator, Julie Vanderwal, as they compose a song to tell the story of change at Triple Creek. Later this spring, Outreach took another field trip to the project site to observe its improvement and to help plant more willow saplings in the riparian buffer zone around the streams. OHA appreciates all the work the Outreach teachers have done to coordinate these valuable experiences for the students, and the many volunteers who make the field trips possible.

This exposure offers valuable insight into multiple facets of science and study. They have been introduced to various fields and disciplines that can inspire and expand their opportunities for the future, including wildlife biology, watershed ecology, botany, geology, and field studies. They are learning about data collection and analysis, record keeping, wildlife photography, and the scientific method of observation. By maintaining connectivity throughout this process we are encouraging an ongoing relationship with these local ecosystems that will last beyond the memory of a single field trip, and encourage stewardship in our future generations.

Surface Remediation Well Underway, Fall 2018

Kinross began removing construction fill from the surface of the mine site and putting it underground even before they finished mining, but that has not reduced the pollution problem. Once mining was complete in 2017, Kinross rapidly began moving the rest of the construction fill into the underground mine shafts; even the fill that was under the treatment facility was moved. To do this, they dismantled the facility without authorization, leaving the mine site without a working treatment facility for a period of six months.

At this point, most of the buildings have been removed and the ground surface has been recontoured and seeded. On the surface, things are looking more natural. However, downgradient wells are still high in sulfates and other contaminants.

Waste Rock

Video Test

(TEST) Nature’s Engineers: How Beavers Restore Habitat

Beavers possess remarkable engineering skills, which they combine with unparalleled work ethic to the benefit of streams and wetlands. On January 7th, 2011, this event focused on how beavers create the stream conditions and wetlands needed by an array of other plants and animals. In the process, beavers are sub-irrigating by raising the water table and increasing groundwater recharge in the Okanogan Highlands, making more water available for everybody during the low flows of late summer. Guest speakers who work with beavers in the field shared from their experiences and answered questions about these curious creatures. OHA also shared some exciting updates about the work of beavers on two of our restoration sites.

HTML Embed (more size flexibility)

Part 1: Introduction

Part 2: The Land’s Council

YouTube Embed (no YouTube logo, one size)

Part 1: Introduction
Part 2: The Land’s Council
Part 3: Methow Beaver Project
Part 4: Okanogan Highlands Alliance
< Past Highland Wonders Events Main Page

The Wetlands

Channel at south end of Lost Lake wetland, impounded by beaver and storing much more water than in previous years, September 2015 (botanist George Thornton on the right)

Click here to view our full photo album of the Lost Lake wetlands year-round!

The Lost Lake calcareous fen, unusual for its almost neutral pH, creates conditions for a unique community of plants.

“The wetlands within the Lost Lake Preserve are of high conservation value due to the rare plants and plant communities which occur there and the fact that the site retains excellent ecological integrity despite numerous human stressors in the surrounding landscape. The site supports numerous wetland types such as a calcareous fen, shrub swamp, and forested seepage swamp. Of particular interest is the calcareous fen, which are rare in Washington and are primarily limited to the northeast corner of the State. Calcareous fens are also one of the rarest wetland types in the United States. Calcareous fens differ from other peatlands in that their pH is circumneutral to alkaline and they typically have a high amount of calcium and other base cations. Such conditions result in a unique set of plants which are able to grow in the fen. One of the more significant plant community types found at Lost Lake Preserve is the bog birch/slender sedge (Betula glandulosa/Carex lasiocarpa) plant association. This plant association is typically found in rich to extremely rich fens (e.g. calcareous fens) and is known to occur in northwestern Montana through northern Idaho and into northeastern Washington. Within Washington it is considered to be very rare. In summary, the Lost Lake Wetland Preserve harbors some significant pieces of Washington’s natural heritage. The long-term protection of this wetland complex would contribute to the conservation of these biodiversity treasures within Washington state.”

Joe Rocchio, WA Dept. of Natural Resources

What Can You Do?

Building a habitat pile
  1. If you enjoy fishing, you can use fishing weights made from non-poisonous materials such as bismuth, steel, clay, rock, ceramic and tungsten-nickel alloy. Non-lead jigs and other tackle are also available. You can find these supplies locally in hardware and sporting goods stores. If you don’t see non-lead tackle, ask for it so the store managers know you care. Many people love to see loons and other lead-sensitive wildlife while they fish. Please pass this information along to others!
  2. You can also stay informed about issues related to rotenone treatment of highland lakes by the WA Department of Fish and Wildlife, and provide public input whenever it is solicited. Read about OHA’s concerns about waterfowl–including impacts on Loons and Black Terns–in our https://okanoganhighlands.org/wp-content/uploads/OHA-Comments_Adoption-15-008-Prog-c8f572e6c4fb4b7d.pdf.
  3. Through ongoing volunteer help, OHA has been steadily improving the habitat for wildlife at the Lost Lake Preserve. View our photo album of habitat enhancement projects!

 

Amphibians

Columbia Spotted Frog (Rana luteiventris) at Lost Lake

A wide variety of amphibians find everything they need to thrive in the Lost Lake Wetland.

The wetland hosts a healthy population of the State Candidate Species, Rana luteiventris, the Columbia Spotted Frog. This species is abundant in the Lost Lake wetland, though statewide it is ranked by the Natural Heritage Program as “Apparently Secure,” meaning that while they are at fairly low risk of extinction or elimination, there is “possible cause for some concern as a result of local recent declines, threats, or other factors.”