Odin Construction Solutions constructed a soil-bentonite cut-off wall to a depth of 48’. The project, located in Milliken, Colorado was the second slurry wall installation on the property to provide cutoff of alluvial groundwater in order to allow mining of sand and gravel and future below grade water storage. The project included installation of approximately 7,690 LF soil-bentonite cutoff wall; outlet pipe installation and backfill; grading including excavation, transport, and backfill; dewatering cut-off wall installation, and miscellaneous infrastructure and appurtenances improvements. The project entailed multiple active utility crossings in which extra precautions and care were required during slurry wall installation. The project team members worked closely with the utility Owner’s to locate all active/nonactive lines to allow for inspection prior to slurry wall installation. Each utility crossing was protected during slurry wall installation.

Prior to constructing the soil-bentonite cut-off wall, the cut-off wall alignment was established, and area cleared and graded to provide a stable working platform for the specialty Long Reach Excavators. Two Long Reach Excavators, one (1) PC-1250 and one (1) PC-800 were utilized on two (2) separate headings for slurry wall installation. In addition, an approximate 1,095 LF dewatering cut-off wall was installed to allow for mass excavation and grading within the outlet structure area. Concurrent with slurry wall installation, mass excavation and grading occurred to allow for outlet pipe installation. Two (2) 36” DIP pipes were installed at the bedrock interface and included a keyed-in clay plug. The installation of these pipes will provide for future pump station infrastructure and transfer of water from each side of the cut-off wall.