- ENGINEERING INFO
- CASE STUDIES
In 2004, Edgmont Township identified the need to abandon its small, community sewage treatment plants in favor of joining a larger, regional sewer system that could serve current and future residents in the growing community. As a new member of the larger Central Delaware Authority, Edgmont Township was able to construct a wastewater conveyance system to connect to the existing Delaware County Regional Water Quality Control Authority (DELCORA) sewer system. This cost-effective partnership enabled DELCORA to be responsible for the design, construction, and operation of the newly formed Crum Creek District.
“This was a tough project with HDD pull-in lengths close to 1,200 feet. For these types of conditions I like using Fusible PVC® pipe.” Gareth Morrissey, Melcar Underground
DELCORA contracted with Bradford Engineering of Aston, PA, to design the 1.45 mile long wastewater force main. The required alignment traversed highly traveled and very narrow Gradyville Road for most of the force main’s 7,650-foot length. Early in the design phase, Bradford identified that pipeline constructability would be the greatest project challenge and determined that horizontal directional drilling (HDD) would be the least costly and intrusive construction approach.
Hydraulic modeling determined that the new force main would require an internal diameter of at least 9.7 inches and be able to handle cyclic pressures in excess of 200 psi. Bradford Engineering specified 10-inch DR18 Fusible PVC® pipe for its internal diameter of 9.78 inches and an operating pressure rating of 235 psi. Most importantly, Fusible PVC® pipe would provide HDD contractors with a monolithic pipe that could be reliably installed by HDD while using industry standard ductile iron fittings at connection points.
|Pipeline Details and Project Summary|
|Project:||Edgmont Crum Creek Sewer: Gradyville Force Main|
|Pipe Size:||10” DR18 Fusible PVC® Pipe|
|HDD Contractor:||Melcar Underground Services|
McKenney Construction contracted with Underground Solutions, Inc. to supply and fuse the 7,650 LF of 10-inch DR18 Fusible PVC® pipe. The project required numerous HDD drills ranging in length from several hundred feet to over 1,000 feet. HDD construction was completed by New Jersey-based Melcar Underground Services. McKenney, an experienced and well-respected local general contractor, excavated all insertion pits, made all connections, and provided support for pipe fusion.
Fusible PVC® pipe’s Hydrostatic Design Basis of 4,000 psi facilitates a smaller pipe OD at equivalent pressure rating and ID versus other plastic pipe options commonly used in directional drilling. When installing pipe via HDD, this results in a lower overall installed cost yielding savings to the end-user.