BETA is excited to announce that a recent project has received ACEC-RI’s highest Engineering Excellence Award. The Bristol County Water Authority’s (BCWA) East Bay Pipeline Sliplining Project is the 2021 recipient of ACEC-RI’s Project of the Year Award, receiving first place honors and obtaining the Gold Anchor Award for projects less than $10 million. The BCWA provides water to approximately 50,000 customers throughout the Towns of Bristol, Barrington, and Warren, RI. BCWA receives 100% of its supply from the Providence Water Supply Board through their East Bay Pipeline transmission main. In April of 2019, an alert was triggered indicating that the main was leaking approximately 400,000 gallons per day.
Initial response activities were focused in the Providence Port area of Providence, approximately 1,000 feet from the shoreline. The initial response included significant challenges as the main could not be shut down and the location was a secure site with several documented environmental conditions requiring significant coordination efforts. Given these challenges and the critical nature of the pipeline itself, BCWA reached out to BETA Group, Inc. as a partner to coordinate and facilitate repairs on the transmission main.
When a sink hole developed along a bank of the Providence River, it became clear that the leak was somewhere beneath the Providence River. With the main still active, a televised inspection of the main was completed and revealed two holes, approximately 1.5 inches in diameter, on existing pipe welds in the middle of the river crossing. At this location, the main is situated in bedrock approximately 170-feet beneath the surface of the Providence River.
Once the break was pinpointed, BCWA contracted BETA to design the repair of the pipeline. The BCWA decided that the repair efforts would best be completed in the fall months when system demand would be lower and emergency interconnections could support the shutdown of the transmission main. This seasonal constraint provided BETA approximately one month to complete the design of the repair and prepare construction documents.
BETA evaluated multiple sliplining technologies and materials based on their installation requirements, hydraulic capacity, and overall costs. BETA ultimately recommended sliplining the existing water main with an 18-inch DR 18 Fusible PVC® Pipe which provided the best water system hydraulics and met the significant pressure requirements due to the depth of the existing water main beneath the river. In September, an existing 16-inch diameter interconnection between BCWA and the City of East Providence was opened to provide BCWA water during the repair. The PVC was fused into 450-foot lengths, with 10 sections of pipe, and was air pressure tested to five psi to confirm that there were no issues with the fused joints. Once the entire pipe was installed, it was successfully pressure tested to ensure continuity following the pullback and intermediate fused joints that were not subject to the initial test. The PVC pipe was then transitioned to ductile iron and permanent connections to the existing steel main were completed. The main was then flushed, disinfected, sampled, and returned to service in the late fall.
Finding a solution that could be implemented quickly, at an economical cost, and with minimal disruption to the existing customer base was of the utmost importance to BCWA and BETA. It was important to BCWA to keep their customer base apprised of the project as its success was critical to providing their communities with a continued supply of water. BETA is proud to have been a part of this complex project and is excited that our team’s hard work has been recognized by ACEC-RI and this prestigious award.