Project Details

Landsburg Mine Site, Phases I and II | Ravensdale, WA


The Landsburg Mine site was a former underground coal mine that closed in 1975. When the mine’s tunnels collapsed, a subsidence trench formed at the surface. In the 1960s and 1970s, several companies dumped an estimated 4,500 barrels containing 500,000 gallons of industrial waste in the trench, which sits near the Clark Springs Water Supply, Cedar River, and private wells. While no groundwater contamination has been detected, a cleanup plan was initiated to prevent the buried waste from spreading to the surrounding environment. This plan included the Landsburg Mine Site Project, which involved the clearing, backfilling, and capping of the waste area.


GBI completed three phases of work that spanned three consecutive summers. Throughout the project, the Washington State Department of Ecology reviewed and approved each reclamation step. The scope of work included clearing and removing trees and vegetation, building access roads, importing 150,000 cubic yards of clean fill, and filling multiple areas of the trench. GBI also installed an impermeable geomembrane liner, drainage layer, structural fill cap, drainage ditches, and pipelines. Some areas of the trench were up to 60 feet in depth, while others had near-vertical walls. Therefore, many areas were difficult to access, which made certain tasks—such as removing trees and importing the fill—especially challenging. Even so, the project went smoothly, and the work was completed safely and efficiently.


GBI received a Health, Safety, Security and Environment (HSSE) Commendation from Golder, the owner’s representative. The commendation acknowledged GBI and its project manager for the proactive response to ensure the protection of the environment and increase site health and safety.

Project Details

Region: Washington
Client: Palmer Coking Coal Company, LLP
Market: Environmental & Water
Value: $1.6 million
Completed: 2020
Services: Demolition / Site Clearing Restoration / Remediation Emergency Response Mass Earthwork / Excavation Water Treatment Wet Utilities

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