Prickly Pear Creek Realignment Project
2017 | East Helena, MT | Environmental & Remediation
Near Helena, Montana, Pioneer led a 5-year remediation of Prickly Pear Creek contaminated by a century of smelter activities depositing arsenic, lead, and other contaminants into soil and groundwater. The project relocated approximately 1.25 miles of creek and its floodplain, removed a derelict dam and impacted reservoir sediments, and permanently lowered groundwater beneath the site. Construction was completed in July 2017. Pioneer received FIDIC 2019 International Merit Award and ACEC 2019 Grand National and Montana Engineering Excellence Awards for this project.
View project sourceLower East Fork Ninemile Creek and Dayrock Complex Remedial Action
2024 | Wallace, ID | Environmental & Remediation
Remediation of riparian areas in the Ninemile Creek Basin affected by historical mining activity. The project involved excavation and removal of over 381,000 BCY of mine waste contaminated with lead and zinc, backfilling with clean materials, reconstructing approximately 1.7 miles of stream channels, and constructing stormwater drainage channels. The four-year construction effort was completed in November 2024, remediating 29 acres.
View project sourceButte Reduction Works Smelter Area Site Investigations
Butte, MT | Environmental & Remediation
Since 2017, Pioneer has led characterization of groundwater and solid materials at the BRW Smelter Area Mine Waste Remediation site in Butte, Montana. Work included drilling approximately 100 boreholes, excavating approximately 60 test pits, performing aquifer pumping tests, installing 52 piezometers, and collecting monthly surface water samples. Pioneer developed a 3D statistical model using Leapfrog Works and a MODFLOW numerical groundwater flow model to guide remedy design.
View project sourceGray's Meadow Remedial Action
Kootenai County, ID | Environmental & Remediation
Remediation and wetland restoration of a 695-acre agricultural field in Kootenai County, Idaho, impacted by mining-related metals deposited through flooding from upstream mining in the Upper Coeur d'Alene River Basin. The design converts the site to functional wetlands with embankment and water control features, loafing islands, and ponds to provide habitat for waterfowl and migratory birds.
View project sourceBenefis Health Systems Outpatient and Surgery Center
Helena, MT | Healthcare
Pioneer performed a geotechnical drilling investigation and foundation design for a new 4-story structural steel building at a former mall site in Helena, Montana. Encountering uncontrolled fill and collapse-prone subgrade soils, Pioneer specified rammed aggregate piers to stabilize the site and oversaw installation quality assurance.
View project sourceUpper Harshaw Creek Mines Environmental Remediation
2021 | Santa Cruz County, AZ | Environmental & Remediation
Remediation of historic mine waste at abandoned mine sites within the Coronado National Forest. Pioneer implemented a Forest Service design to construct three consolidation cells, remove over 78,000 cubic yards of contaminated waste rock and tailings from five abandoned mines, and perform road building, reclamation, channel construction, and adit and shaft closure. Work was completed between 2021 and December 2021.
View project source