Less than three years after the record-setting 5,120 LF Secession Effluent Main project was successfully completed, Beaufort Jasper Water & Sewer Authority (BJWSA), Mears Group, Inc., and Underground Solutions, Inc. (UGSI) have set a new record for the longest single continuous horizontal directional drill (HDD) pullback of thermoplastic pipe.
In September 2008, BJWSA assumed ownership, operation, and maintenance responsibility for the water and wastewater systems at several local military facilities, including the Marine Corps Recruit Depot at Parris Island, SC. As part of the merger, all of the water and sewer utilities are undergoing upgrades and improvements. Due to restrictive Beaufort River discharge requirements, the military wastewater plants at the Air Station and Parris Island will be eliminated with flows diverted to the state-of-the-art Port Royal Island, SC Water Reclamation Facility.
Project: Military Wastewater Consolidation Project
Owner: Beaufort Jasper Water & Sewer Authority
Engineer: Hussey, Gay, Bell & DeYoung (HGBD)
Contractor: Mears Group, Inc.
Location: Beaufort, SC
Length: 6,400 LF
Pipe Size: 16” DR18 FPVC®
Pressure Test: 150 psi for 4 hours
UGSI Contact: Gary Shepherd; firstname.lastname@example.org
The new sewer force main from Parris Island was installed under Archer’s Creek and the surrounding marsh via HDD to ensure minimal impact to the environment. Mears Group mobilized in October 2009 with two drill rigs, prepared to use the intersect method to complete the pilot drill if necessary. Ultimately, the 6,400 LF pilot drill exited on target without requiring the use of intersect technology. The bore hole was reamed out in three passes to a 32” diameter, then prepared by swabbing with a barrel reamer to clear cuttings and reinject clean slurry.
On December 2, 2009, the 6,400 length of fused 16” DR 18 FPVC® pipe was positioned on rollers and pulled into place with an excavator. The pull head was then connected to the drill stem to begin the process of pulling the pipe from Horse Island, under Archer’s Creek, and onto Jericho Island. The pipe emerged during the predawn hours of December 3rd to the applause of the small group of interested bystanders and a much larger number of tired, but satisfied workers.
Ed Saxon, BJWSA Deputy General Manager, commented: “The force main leaving Parris Island became a real design challenge because the narrow causeway linking the mainland was off limits to construction. Open cutting across the salt marsh would also have been very difficult, even had it been possible to permit. BJWSA’s growing body of experience with long HDD installations and recent advances in the technology made drilling the only viable option. Fusible PVC™ pipe was the only practical alternative for us, and we’ve had great experience with Mears Group as well.”
Jennifer Oetgen with HGBD remarked: “The design was critical to a successful outcome; early onsite consultations with representatives from Mears and UGSI confirmed the viability of a 6,400 LF HDD, but the possibility of an intersect drill, staging that length of pipe, and working within the requirements of the military made this project particularly challenging and satisfying.”