Record Breaking 10-inch Fusible PVC™ Project in Beaufort, South Carolina

Mears Group, Inc. successfully installed a record breaking 5,120 ft. horizontal directionally drilled (HDD) crossing of 10-inch diameter Fusible PVC™ pipe under the Beaufort River for Beaufort Jasper Water & Sewer Authority (BJWSA). The pipe will connect the Port Royal Water Reclamation Facility with the Secession Golf Course in Beaufort, South Carolina. This project was completed on June 12th and marked the longest single HDD crossing of thermoplastic pipe in history.

This length of bore was previously unheard of for fusible thermoplastic pipe. Edd Birdwell, Project Superintendent for Mears, said, "Drilling a length of over 5,000 ft. for fusible polyvinylchloride pipe had never been done before, so we had to take many precautions to ensure the successful completion of the job." BJWSA contracted with Underground Solutions Inc. (USGI) to supply its unique, proprietary Fusible PVC pipe for the job. This pipe was a key component in the successful completion of the job.

Mears' 330,000 lb capacity rig was used on the entry side of the crossing and one of its 60,000 lb. rigs was used on the exit side during pre-reaming to apply tension on the cutters. The bore reached a maximum depth of about 80 ft. through sandy limestone and silty sand. According to Birdwell about 95 percent of the drilling was through good conditions, while the remainder of the drilling was "choppier" which made the drilling tough.

Installing fusible polyvinyl chloride pipe with HDD is not yet as common as using more traditional steel or HDPE materials. Mears was very careful throughout the HDD operation and especially in handling the pipe during the pullback operation. They did not exceed 67,000 lbs. of pull on the pipe throughout the installation. This allowed them to stay well under USGI's warranted Safe Pulling Force of 100,000 lbs. Previously, UGSI had only seen their Fusible PVC pipe installed in drills of up to 1,480 ft. and a slipline installation of 3500 ft.; however, they were confident that their pipe could be successful in longer drills. UGSI Vice President, Tom Marti, said, "Great cooperation between Mears, BJWSA and UGSI allowed for this groundbreaking success." Marti also mentioned that attention to detail and intense planning were critical to completing the job on time and with record-breaking results.