Subsidence Mitigation — Southwest Wyoming
AML 17.6 Series (17.6B / C / D)
$132.5M+ combined
Long-running abandoned mine land subsidence mitigation program across three phases. Phase 17.6B (2015–2020): 303,053 CY of grout injected, $66.3M. Phase 17.6C (2021–2023): 116,500 CY of grout, $44.2M. Phase 17.6D (2024–ongoing): 33,550 CY of grout, $22.5M. Western-EGI provides inspection, engineering, and materials testing throughout — including gradation, temperature, slump, unit weight, vicat, and strength testing. Developed fly ash alternatives when regional supply disruptions threatened program continuity. Client: BRS Engineering (Harold Hutson).
Nuclear CMT & Geotech Lab — Kemmerer, WY
Natrium Reactor — TerraPower / WSP
$4B+ Project
Construction materials testing and laboratory testing services for the Natrium advanced nuclear reactor in Kemmerer — one of the most significant energy infrastructure projects in Wyoming history. Testing includes moisture-density curves (ASTM D1557 / D4253), moisture content, Atterberg limits, grain size analysis, concrete cylinder breaks, and grout cube breaks. Western-EGI was selected for AASHTO-certified lab capability and regional presence. Client: WSP USA (Adamson Mwembeshi, PE).
Deep Drilling & Rock Mechanics — Green River Basin
Confidential 2023 Mineral Exploration Program
~$4.5M
Geotechnical drilling and coring program to approximately 2,000 feet below surface for mineral exploration in the Green River Basin. Roads and drill pads were constructed to mobilize drill rigs. Core was geologically logged by Western-EGI — including geological description, total core recovery, solid core recovery, rock quality designation, and e-logging. In-house rock mechanics testing included triaxial, unconfined compression, and Brazilian Split tests. Client: Confidential — one of Wyoming's largest mining operations.
Subdivision — Rock Springs, WY
Mustang Ridge Subdivision
$3M+
Geotechnical investigation, foundation recommendations, and retaining wall design for this 40+ lot residential subdivision in Rock Springs. Western-EGI performed subsurface investigation across the development, provided foundation and flatwork recommendations for individual lots, and designed retaining walls for the east end of the subdivision. Geotechnical services were coordinated directly with the civil and infrastructure design team under the same contract. Client: Amundsen Construction.
Forensic Geotechnical — Blackhawk, SD
Hideaway Hills Abandoned Gypsum Mine
~$34M Est. Affected
Forensic subsidence investigation for a residential subdivision in Blackhawk, SD where a 2020 subsidence hole revealed active collapse from an abandoned historic gypsum mine. Over 150 homes are affected, several evacuated. Western-EGI was retained by Fox Rothschild in 2021 to evaluate the full extent of risk, inspect homes for subsidence damage, and complete a preliminary drilling program to characterize the geology beneath the subdivision. Investigation and litigation support ongoing. Client: Fox Rothschild LLP (Kathleen Barrow).
Geotechnical & Track Engineering — Rock Springs, WY
Rock Springs High School Track
~$1.5M
Geotechnical investigation, topographic survey, and special inspections for the RSHS track reconstruction. During removal of the existing field, unforeseen trapped moisture was discovered — caused by an impermeable membrane that had been installed beneath the field. Geotechnical drilling had not been permitted on the field itself, so the problem was previously unknown. Western-EGI worked with the school district and owner's representative to design a solution that kept the project moving without compromising the timeline. Client: Sweetwater County School District No. 1 (Dan Selleroli).
