- ENGINEERING INFO
- CASE STUDIES
Established in 1897, the Middlesex Water Company provides a full range of water, wastewater and related utility services, primarily in New Jersey and Delaware. The Middlesex system provides water services to approximately 59,800 retail customers within a 55-square mile area in north-central New Jersey. To continue to maintain a high level of customer service, the utility embarked on a replacement plan for a 104-year old, 24-inch cast iron water main that had experienced an increasing rate of failure.
David Tanzi, P.E. of CDM in Edison, NJ led the engineering effort on behalf of the Middlesex Water Company to evaluate options for a new water transmission main extending from the company's northern distribution system near the City of Perth Amboy, across the Raritan River into Sayerville, connecting into its South River Basin regional supply system serving Southern Middlesex County, NJ. A critical segment of the pipeline included crossing a 4,800' wide section of the Raritan River. Several alternative construction methods for the crossing were evaluated, including open-cut trenching, micro-tunneling, pipe jacking, conventional tunneling, and horizontal directional drilling (HDD). Factoring in construction schedule, cost, sustainability, impact to the environment, disruption to marine traffic, and permitting requirements, HDD was selected as the most cost-effective and minimally invasive approach. Fusible C-905® pipe was selected for the HDD crossing based on its high strength, favorable ID/OD relationship, and proven track-record in long HDD installations.
In February 2010, Underground Solutions, Inc. (UGSI) contracted with Northeast Remsco Construction, Inc. of Farmingdale, NJ to provide 5,400 LF of 24" DR18 Fusible C-905® pipe and fusion services for the project. Northeast Remsco selected Mears Group, Inc. of Rosebush, MI to complete the river crossing HDD and pull-in. Due to constrained layout space, four pipe segments were fused and pre-staged in an empty lot adjacent to the drill site. The 5,365 LF, 190 ton pipeline was installed with three intermediate fusions completed during the pull-in. The drill alignment was over 65 LF deep under the Raritan River. A maximum pull force of 165,000 lbs was recorded during the 23-hour pull-in. The pipeline was placed into operation in May 2010, following a successful 175 psi pressure test and reconnection. The new record-length crossing was completed on schedule, thanks to careful planning, engineering, and execution by all parties involved.