FY01 MCON Project P-491,
Sewer Force Main - Ford Island to Pearl Harbor Naval Shipyard

Pioneering in Use of Materials and Methods

The use of HDPE pipe installed by HDD offered the following advantages:

• HDPE is non-corrosive to both wastewater and seawater.
• HDPE pipe was able to flex and curve around physical obstructions minimizing the need for fittings and other appurtenances that would have added cost to the project.
• HDD caused minimal disruption of marine and on-land operations.
• This was the first project to utilize HDD for a submarine crossing at Pearl Harbor.
• The Main Channel crossing was the longest single-pull HDD installation to date using HDPE pipe.

Innovations in Construction

The use of HDPE pipe installed by HDD required several innovations in construction:

• The use of HDD to install large diameter, heavy-walled HDPE pipe is relatively new to the industry. The tensile stresses developed while pulling the pipe through the borehole could potentially damage the HDPE pipe. The designers partnered with the drilling Contractor to carefully monitor the drilling and pull-back forces to ensure proper installation.
• The ability to accurately install the submarine pipeline was critical to the project�fs success. It was imperative that the drill head did not exit the ground and damage any of the historic features on Ford Island. With historic bomb craters located within 30 ft of the exit hole, the drill path needed to be accurately tracked at all times. A wire grid system laid on the sea floor allowed accurate tracking of the drill head path, and resulted in an exit hole within centimeters of the design point.

Impact on the Physical Environment

Application of HDD techniques resulted in minimal impacts on the physical environment.

• No contaminated sediments were disturbed.
• Dewatering and associated problems were avoided.
• Handling and disposal of contaminated groundwater and excavated soil was minimized.
• Significantly less construction-related disruptions were encountered compared with conventional, open trenching methods.
• Disturbance of the numerous historical features along the pipeline alignment was avoided.

Beneficial Effects of the Project, Including Aesthetic Value

Beneficial effects of the project include:

• The reliability and capacity of the Ford Island wastewater collection system is greatly enhanced.
• The Navy can proceed with its much-needed revitalization of Ford Island.