Written by Shawn Maxfield, Published on May 22, 2024
HRSD has over 40 projects across the Hampton Roads areas, many consisting of pipe installation on land, which can be tricky at times. But imagine trying to install a pipe underwater! As part of the Boat Harbor Treatment Plant Conversion and Transmission project, Garney Construction took on this challenge. This suite of projects includes three key parts on the peninsula: the Boat Harbor Pump Station Conversion, the Boat Harbor Underwater Transmission Pipe Installation, and the Boat Harbor Land Transmission Pipe Installation. In this blog, I am specifically diving into the Boat Harbor Underwater Transmission Pipe Installation.
On Monday, April 29th, I had the pleasure of attending a boat tour to get a close-up view of the barges and 5,700 feet of fused pipeline that would be installed 168 feet under the Newport News shipping channel on May 1st.
To dig under the shipping channel, Garney Construction utilized a Horizontal Directional Drilling (HDD) method to create a hole for the pipe to be pulled through. They began by drilling an initial 12-inch diameter hole and then gradually enlarged the size until it was 54-inches. The HDD was performed from a temporary work platform located in the James River, just south of the Newport News shipping channel, to the northern shoreline. Pictured above, the pipe was propped up on the barge, marking the starting point of its journey under the shipping channel.
The second barge (below) closely followed the first one, equipped with a crane that dug a trench in the water. I was surprised to see it mimic the process used on land by preparing a path for the pipe to be installed in a trench as it progressed towards the shore in Suffolk. I thought due to the water’s movement from the tides, the trench wouldn’t stay in place, but divers were sent down to ensure the trench remained.
Finally, the boat took us to get a view of the 5,700-foot-long fused pipe that was made by welding 108 sections of 53-feet-long pipes together on a barge in the river. Each fusion took 2 hours, and the crews worked around the clock. There was a white metal tip on one end (below) with a ring at the end that was hooked to a pipe through the 54-inch hole that was dug; this tip was floating in the water.
The other end (below), was propped up on a barge to prevent it from being filled with water. Ultimately, the 31,000-foot-long pipeline will transmit sewage from the Boat Harbor Pump Station and across the James River to the Nansemond Treatment Plant for additional rounds of advanced treatment, further recharging the Potomac Aquifer. This undertaking is truly amazing.
The pipe was pulled through the hole in one continuous 22-hour operation that started on May 1, 2024, and finished on May 2, 2024. Garney Construction and HRSD are very thrilled about this record-breaking project. I am glad I had the opportunity to witness such an impressive process firsthand.
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A special thanks to Rod Melvin for providing the great images! For more information on the project, please visit the project webpage at www.hrsd.com/boat-harbor-treatment-plant-conversion-and-transmission. For more information about recharging the Potomac Aquifer, please visit www.hrsd.com/swift.