Deptartment of  Veterans Affairs Sewer System Rehabilitation & Replacement

Bedford, MA

AI provided survey and design services for the rehabilitation and replacement of approximately 10% of the site’s approximately 14,000 lf of sanitary sewer collection and conveyance system. The project was divided into four phases. The Phase 1 field services portion of the project involved a topographic/feature location survey of the project area, and a survey of the existing sewer system (manhole locations, pipe inverts, pipe materials, etc.). AI also performed field inspections of the existing system that involved condition evaluations of manholes, photo documentation, and working with the VA’s maintenance staff to obtain closed circuit video of the sewer lines within the project area.  AI reviewed all inspection videos to document defects and condition, for use in the Phase 2 feasibility study. Phase 2 of AI’s consulting services was to review the survey and inspection data from Phase 1, and prepare a feasibility study outlining the inventoried sewer system components and, provide a course of action for the design portion of the project. AI determined that a substantial cost savings could be realized for the project by combining sections of the existing system into a common main, thereby saving the costs of replacing multiple sewer mains within a localized area. Phase 3 AI then provided design services that included plans, specifications, and a construction cost estimate for the proposed improvements. The VA site was especially challenging due to the need to maintain sewer service throughout construction, minimize impacts to a busy hospital campus, and the presence of extensive underground utilities that have been installed over the approximate 100-year history of the site. AI developed a plan of sewer pumping bypass, and a combination of traditional excavation and innovative installation techniques to minimize impacts and project costs. A combination of pipe bursting and cured-in-place pipe lining was used for installation of pipe in several areas, which preserved historic stone walls, negated the need to open cut busy roadways, and preserved numerous old trees on the site. Phase 4 of the project required CEI services, where AI reviewed and approved contractor submittals and provided construction engineering and inspection.

Highlights 

  • Duration: 2011- 2013
  • Project Scope:
    • CCTV condition evaluation of sewer collection & conveyance system
    • Utility planning to reduce site impacts & cost
    • Use of innovative technologies for system installation