Abandoned Coal Mine Mitigation in Artesian Conditions-Video

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Video Summary

Joshua Zimmerman describes a 2021 project to address subsidence and sudden basement flooding above the abandoned Glenrock coal mines in Wyoming. The mine’s sloping, water-filled workings created high artesian pressure, which traveled through fractures in weak overlying rock and raised groundwater levels at the surface.<br /><br />A pilot program tested high-mobility grout, groundwater monitoring, and controlled discharge in an open field before work began beneath homes. The team used settlement boxes to check for movement and discharge wells to relieve pressure while grout filled mine voids and fractures.<br /><br />The full project treated a 14-acre subdivision using nearly 600 boreholes and about 24,500 cubic yards of grout. Six discharge wells and a network of monitoring wells helped control and track groundwater throughout the five-month operation. Artesian pressure declined in some areas, and residents reported no continuing flooding or subsidence problems. One homeowner was able to see a previously flooded crawl-space floor for the first time in decades.

Keywords

coal mine subsidence

basement flooding

artesian pressure

grout injection

groundwater monitoring

Wyoming mining remediation