search
menu

Tailings basin expansion and closure options

About this project

client
PolyMet Mining Corporation
location
Minnesota
cost
$1 billion
completion date
Ongoing

Part of the environmental permitting effort for PolyMet’s proposed copper-nickel and precious-metal mine included tailings-basin closure planning. Barr evaluated both wet and dry closure approaches for the basin. A “wet closure” approach would consist of a large pond surrounded by wetland and meadow areas to cover the basin, limit oxygen intrusion into the tailings, minimize water-quality impacts, and accommodate wetland mitigation at the time of basin closure. A “dry closure” approach would include surface contouring to shed surface water, a hydraulic barrier to limit water infiltration, and a vegetated soil cover. We studied water-quality impacts for both of the closure options, as well as constructability, long-term maintenance, and slope-stability factors of safety for the basin.

Key team members

Tina Pint

Vice President
Senior Hydrogeologist

Tom Radue

Vice President
Senior Geotechnical Engineer

Related closure and reclamation projects

Park and landscape design for Mouse River enhanced flood protection project
Design of abutment wall extension at Dells hydro station
Phase I ESA for copper-nickel project
Coffee Creek trout stream restoration
Ore transportation study
Dry-stack tailings management
Permitting, environmental assessment, and design for copper-nickel mine
Investigation and remediation of jet-fuel release
Vapor intrusion investigation and mitigation in a residential neighborhood
Snowpack monitoring and lake drawdown for Minnesota watershed district
Geotechnical investigation and design for expansion of ancient gold mine
Penn Avenue sinkhole investigation and rehabilitation
UMore Park environmental services
Scoping study to increase magnetite-concentrate production capacity
Mine closure and reclamation
Landslide stabilization design for an underground coal mine
Geologic modeling and mine-plan development for aggregate quarries
Resource estimates for neodymium-rich rare-earth-element exploration project
Advanced oxidation process pilot evaluation for municipal drinking-water system
Waste-gas scrubber design engineering for taconite pellet plant
Reciprocating internal combustion engine (RICE) applicability analysis and audit
Responding to wind-farm tornado damage
Upgrades and expansion for silica-sand wet plant
Reclamation of legacy tailings site
Evaluation of wind-turbine foundation following fire damage
Engineering services for frac-sand operation
Environmental review and prefeasibility design for planned uranium mine
Groundwater modeling for wellhead-protection-plan amendment
Multi-site PFAS remedial investigation and remediation
Sediment removal from beneath Vermillion River bridge
Monitoring of end-pit lake at oil sands mine
Highwall stability assessment
Flood risk reduction of suburban lakes
Letter of map revision for Minnesota city
Options study and design to restore biomass fuel-handling system
Mine remediation and reclamation
West River Parkway landslide repair
FERC relicensing of Ford Lake Dam
Tailings-management area design and construction
Spillway design for iron-ore-mining and mineral-processing facility
Groundwater compliance assistance for CCR Rule
Hydrologic study of North Dakota lake
Environmental site assessments for future site of mining and processing facility
Floodproofing of utility switchyard
Resource assessment and permitting assistance for industrial sands facility
Flood mitigation at refinery
Engineering services for industrial chemicals mine and processing facility
Wetland replacement assistance for highway project
Trona-mining production optimization
Environmental support for post-fire cleanup at industrial facility
Geotechnical assistance for mine expansion at Julienne Lake
Lilydale Regional Park stormwater management and slope stabilization
PFOS investigation at municipal wastewater plant
Response to denatured ethanol release
Compliance, resource, and process evaluations for potential mining sites
Aquatic invasive species (AIS) management in a Wisconsin lake
Solar-energy-system compliance
Berm-failure study at saltwater disposal well site
Preliminary feasibility study for PFAS-related water quality concerns
Rockford dam removal
Groundwater modeling and remedial improvements at closed landfills
Stressor-identification report for an impaired urban stream
Post-flood stream assessment and natural channel design