Warren Waste Water Treatment Facility

McCrossin Foundations installed a temporary cofferdam for the construction of a new headworks and pump building for water treatment plant upgrades. The cofferdam consisted of 98 pairs of PZ-35 sheet piles, driven to a depth of approximately 45 feet. The sheets were driven through 10 feet of loose sand and approximately 35 feet of dense to very dense sands and gravels before hitting bedrock.  In some locations, the borings indicated blow counts in excess of 60 throughout the driving zone. The sheets were installed using an HPSI-500 vibratory hammer with an 80-ton crawler crane. A 3-foot square reinforced concrete ring was installed inside the cofferdam to resist overturning. The General Contractor was able to excavate the required 28-foot depth to install the new headworks and pump buildings.