Subaqueous Force Main Replacement

Force Main Replacement Using Horizontal Directional Drilling in Naples, FL

The City of Naples needed to replace approximately 3,500 feet of ductile iron force main that passes under Rock Creek and the Gordon River. The force main is considered critical infrastructure because of its proximity to the water reclamation facility. The age and condition of the force main were a concern, as was the nearby marina office constructed over the force main, making it difficult to access in the event of a break or leak. The city retained Weston & Sampson to design and permit a newer, more reliable force main to replace the aging one.

Weston & Sampson developed a series of preliminary alignment sketches, working with the city to determine the most appropriate location for the new main. Our team looked at various potential installation methods, including pipe lining of the existing pipe. Ultimately, we determined that horizontal directional drilling (HDD) would be the best method of installing the new main under the waterways, using 24” pipe under the Gordon River and 20” pipe under Rock Creek. The project also involved adding a new meter assembly to an existing 30” force main near the water treatment facility. We established the connection details for the new main, determined which sections of pipes to remove and which sections to grout in place, and then designed a route for the new main that does not travel under the marina building (reducing the length of new pipe required by 700 feet).

The permitting process included an Environmental Resources Permit (ERP) from the Florida Department of Environmental Protection and a permit from the US Army Corps of Engineers (ACOE). Our team expedited the ACOE permit in only 10 days, which accelerated the bid process. Once the permits were obtained, we prepared a construction package for bidding and assisted the city in evaluating the bids received.

At the city’s request, Weston & Sampson will provide construction administration services for the installation of the new force main. The Naples City Council has approved the project, construction is expected to begin soon, and the city will realize its goal of replacing an aging piece of their critical infrastructure with a modern, accessible, and more resilient force main.

Key Project Features:

  • subaqueous force main design and replacement
  • 20”, 24”, and 30” pipe diameters
  • design and permitting
  • horizontal directional drilling
  • public bidding assistance
  • construction administration


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Posted in Industry-Municipal, WWSewerRehab and tagged , .