Campbell Street Sewer Replacement

Allenstown, New Hampshire

Client: Town of Allenstown, New Hampshire


  • Bidding
  • Construction Administration
  • Construction Observation
  • Easement Assistance
  • Final Design
  • Permitting & Approvals
  • Study and Evaluation
  • Use of Trenchless Technology

Project Summary

This project consisted of replacement and relocation of approximately 800 feet of very old existing 6-inch diameter clay sewer pipe that was known to have structural deficiencies, was a significant source of infiltration of groundwater into the sewer system and did not meet standards of design. During the study phase of the project, Hoyle Tanner completed internal television inspection, flow metering and evaluation of the existing sewer. A significant portion of the sewer line was located within a residential private property.

Hoyle Tanner designed a new 8-inch replacement sewer in a new location in order to relocate the sewer to the public right of way as much as possible. The new sewer was designed to be constructed using open-cut trench construction; however, one of the bidders submitted a bid proposal that included the use of horizontal direction drilling (HDD) trenchless technology as an alternative to open-cut construction. The HDD alternative was bid at significantly lower cost than the open-cut alternative and was approved by Hoyle Tanner and the Client due to its lower cost and lessened disturbance from construction operations. The use of HDD technology proved to be quite successful and resulted in the project being completed under budget and on time while minimizing construction disturbance.

Click on thumbnail to view