Secondary Extraction Froth Pond Project
Geography: fort mcmurray, Alberta
Industry: Oil & Gas
Materials: Geotextile, Geonet, White DS 60 mil Super Textured HDPE, White DS 80 Mil Super Textured HDPE (4:1 SLOPES), 60 mil and 80 mil Smooth HDPE (BASE)
Duration: 3 months
Project Description
During the process of the award of this project from the General Contractor to ECI there was great discussion about the design and layers of materials being installed within this liner system. Due to the length of slopes and thickness of coverfill layer being placed on the liner ECI was very concerned that the materials would not stay on the slope due to the slope friction angle.
After a long discussion ECI was directed to proceed forward with the original design but due to the late start in the construction season only ¾ of the pond was completed with all 5 layers of materials. Upon ECI’s arrival back to site the following spring the materials had creeped halfway down the slope by expansion/contraction jacking which happens in these conditions.
ECI returned to site with a large crew after discussions with the Engineering Firm, Owner, and GC who directed ECI to remove the installed liner from the pond with ECI’s proprietary liner rewinder so the materials could be reused elsewhere on the site. ECI then replaced it with what it had originally recommended; textured liner which met the slope friction angles.
outcome
The successful completion of this project led to the same changes on another project scope on the same site. The Owner is pleased with the value-engineering, quality, and schedule completion.
lessons learned
From design to construction there was very little time at bidding stage to allow for clarification questioning. More time at the design or bid stage would have led to a more positive and cost effective outcome.