Ballard assembled a dive team to inspect the length of the two three-and-a-half-inch gas pipelines that crossed beneath the Sacramento River.
Scope of Work
Inspection included a detailed report and video recording of the general sounding, pipeline soil integrity (buried, exposed, spanned), pipeline coating condition, large debris covering the pipeline (large rock, trees, etc.), and any abnormalities with the pipeline itself or the riverbed.
Prior to performing the dive inspection, two buoys were deployed to notify potential boaters of a diver in the area, each 100 yards upstream and downstream of the inspection zone. The dive boat was secured to the eastern bank where thirty-two-inches of a single three-and-a-half-inch gas line was exposed as it descended into the water. The diver began the survey from the eastern bank and began searching the riverbed by performing bottom sweeps (twenty feet to thirty feet, north to south) every ten feet, as the diver headed westward.
The diver probed the riverbed while performing survey sweeps to identify the gas line. Once the diver surveyed approximately sixty percent (144 linear feet) of the riverbed heading westward, the diver was recovered, the dive boats were then relocated to the west side where the diver would continue the survey, heading easternly from the west bank to survey the other sixty percent of the riverbed to ensure overlap on the survey. The Sacramento River current was flowing approximately one to one point five knots throughout the project. The diver was able to utilize additional weight to stabilize himself to the river bottom in the current.
Ballard concluded the inspection providing the client with a detailed report and video recording, as outlined in the scope of work.
Client: Pacific Gas and Electric
Location: Sacramento River, Coulsa, CA
Diver Depth: 15ft