Cedar Ridge Reservoir & Transmission Main*

More than 40 percent of the pipeline alignment ran through basalt. Early borings suggested a rippable layer, but the CM/GC pricing phase showed continuous rock at 4 to 12 feet along 3.1 miles, a condition that could have cost the owner millions in post-award change orders.

The site sits in a high-desert climate with winter freeze cycles, narrowing the window for tank wire-winding and shotcrete application.

We commissioned additional borings and seismic refraction surveys during preconstruction, then negotiated a unit price for rock excavation that put hammer and controlled-blasting risk in the GMP rather than leaving it as an unknown. Blast designs were reviewed by the county fire marshal, and vibration was monitored at 31 nearby structures.

Steel pipe was installed in 40-foot joints with field-welded and mortar-lined joints, each inspected by radiographic testing. The reservoir wall was wound in a single heated enclosure to hold the shotcrete cure temperature above 50 degrees through January.

The reservoir and main were energized 36 days early and $4.2 million under the GMP, with the owner receiving 100 percent of the savings. The pipeline passed hydrostatic testing at 1.25 times working pressure on the first attempt, and blast vibration stayed below the 0.5 inch-per-second limit at every monitored structure.

The project logged 0 lost-time incidents over 301,000 hours.