Mitigate the melt - your solution to managing excess freshet water.
Last year was one of the warmest on record, according to an analysis by scientists from NOAA's National Centers for Environmental Information (NCEI). 2022 was ranked as the sixth-warmest year on record since 1880 [1]. Across the Northern Hemisphere, surface temperatures were the sixth-highest recorded since 1878, when such records began. Rising temperatures and seasonal changes bring risks and challenges to the mining industry.
As the weather warms up, freshets occur when a spring thaws, leading to snow and ice to melting which results in excess groundwater which can impact operations and prevent ongoing production. When combined with heavy rainfall or extreme snow dumps, the impact of freshets can be significantly greater, potentially impacting infrastructure, roads, Tailings Storage Facilities (TSF) and waste dumps. As a result, infrastructure may breakdown or fail, leading to significant environmental and safety impacts.
The impact of freshet snow melts on the mining industry
Mine sites tend to experience a particularly conflicting time period during the spring and early summer months. As the weather begins to warm up, snow and ice melt, causing freshets that make conditions unfavourable for ongoing production. Snowmelt runoff resulting from a change in temperature can have damaging consequences, flooding mines and waterlogging them. This dangerous situation not only puts the equipment at risk but also hinders progress as operators on these mine sites need to shift their focus away from mining functions towards emergency management tasks. A temporary shutdown of operations may be imminent without mitigation and effective water management strategies in place.
Sibanye-Stillwater’s uranium and gold mines located in the area of Montana have been an economic force for many years, however last year it recently faced a devastating flood event [3]. This was triggered by the warm weather with freshets forming due to rapid snow and ice melts, which was further intensified by excessive rainfall over the weekend. This situation created substantial damage with significant repair and recovery efforts to bring operations back up to full capacity. Operations were suspended in the wake of the crisis, as the scale of the flooding was so disastrous that several months later, revenue losses were strongly felt.
Minto Gold Mine in the Yukon territory of Canada experienced a challenging second quarter of 2022 and was impacted heavily by freshets and excess water from snow and ice melts [5]. Snowfall in the region was 150% - 400% higher than normal, with freshets causing operations to be temporarily suspended for four and a half weeks costing the company millions [6]. Over the three month snow melt period, Minto Mine recorded a record loss of $9.5 million CAD, adjusting the EBITDA from a profit of $8.72 million CAD to a loss of $941,000 CAD [5].
North American regions affected by freshets and snow melts.
Mine sites in northern climates such as Canada and America must be prepared for the unique challenges posed by snowfall. Spring freshets and snow that has accumulated within the tailings footprint area begins to melt and the resultant water either has to be discharged or contained within the TSF. During these short and intense periods the daily water inflow exceeds the discharge capacity of a mine, leading to the rise of water levels in TSF’s.
Tailings and water storage facilities are pushed to their limits during this time with impoundment areas potentially reaching the maximum allowable water level. Without proper water management planning and risk mitigation strategies operations may be forced to temporarily halt production. Increased pressure on TSF levels can pose a serious threat of dam failure if water levels are to exceed capacity limits. This can result in permanent environmental damage, as toxic acid water may be released into surrounding areas.
North American locations impacted by freshets and snow melts
Canada
- British Colombia
- Yukon
- Alberta
- Saskatchewan
- Manitoba
- Ontario
- Quebec
- Nova Scotia
- Northwest Territories
- Nunavut
- Newfoundland
- Labrador
United States of America
- Nevada
- Idaho
- Utah
- Colorado
- Alaska
- Wyoming
- Montana
- Washington State
- North Dakota
- South Dakota
- Minnesota
- Wisconsin
- Michigan
- Ohio
- Kentucky
- Tennessee
- Missouri
- West Virginia
How can mine sites across the Northern Hemisphere prepare?
Mine sites across Canada and the United States can prepare for freshet springs and increased water inflow by implementing an effective water management plan and vigilant monitoring of changes in environmental conditions [6]. Emergency response and contingency planning for run off water must be in place or set up for rapid implementation. Mines located in high-risk locations may need to regularly assess water management and plans to ensure that all personnel are aware of their roles and responsibilities along with resources required to implement such plan.
Mines located in high snowfall regions are constantly looking for more efficient and effective ways to mitigate the safety, environmental, and commercial risks of freshet snow and ice melts. One particularly promising solution is the implementation of a water evaporation system designed to remove excess water, reduce dam water levels, and ensure compliance with global standards. Minetek provides a promising solution in this area, developing a specialised Evaporation System that offers cost-effective solutions for mine operations across North America.
Minetek’s water evaporation solutions
Minetek's Land-Based Water Evaporator is an innovative creation that embodies advanced fan engineering and airflow principles and is designed to specifically evaporate wastewater in an efficient, cost-effectively, and sustainably. Our Water Evaporators are uniquely capable of evaporating water ranging from pH 2.2 to pH 12, acid water, caustic water, high TDS and TSS, etc. Minetek's units can evaporate on average 50% of the volume pumped through the evaporator. Minetek allows our customers to maximise performance and efficiency when using our equipment. Our patented nozzles are specially designed and engineered to process even large solids up to 4.0mm in diameter, enabling longer life cycles and consistent performance. For mine sites with smaller footprints, we offer floating wastewater Evaporators that boast the same capabilities as the Land-Based Evaporator but are situated on a floating pontoon.
Minetek Water has sucessfully completed over 500 projects in 25 countries worldwide. Our Floating Wastewater Evaporator is optimal for managing excess wastewater from freshets and snow melts. Minetek's robust design system and commitment to delivering high-quality products make us an excellent choice for advanced and reliable water management.
Contact Minetek if you are looking for an effective and environmentally friendly way to dispose of excess water from snow melts.
Resources
- National Centers for Environmental Information - https://www.ncei.noaa.gov/news/global-climate-202212
- World Mine Tailings Failures - https://worldminetailingsfailures.org/
- Mining Journal - https://www.mining-journal.com/pgms/news/1434114/flooding-hits-sibanye-stillwaters-us-operations
- Scripps Media - https://www.ktvq.com/homepage-showcase/we-have-never-experienced-a-loss-like-this-stillwater-mine-still-dealing-with-impacts-of-june-floods
- Mining Journal - https://www.mining-journal.com/commodities/news/1438297/freshet-takes-spring-out-of-minto%E2%80%99s-step
- Mining Weekly - https://www.miningweekly.com/article/spring-freshet-impacts-on-minto-2022-08-24
- Ministry of Energy, Mines and Low Carbon Innovation - https://www2.gov.bc.ca/assets/gov/farming-natural-resources-and-industry/mineral-exploration-mining/documents/health-and-safety/health__safety_notice_freshet_2022_1.pdf