DuPont Liner


The project involves the following tasks:

  • Data gathering, project management, scheduling to meet established milestones.
  • Contracting with and overseeing an SSES/investigation of sewers and manholes: Cleaning, CCTV, flow isolation inspection, smoke testing, dye water testing, sonar inspection, laser profile, manhole inspection.
  • Preliminary Engineering Report with recommended improvements. Priorities, costs, plans, present worth analysis, alternative analysis, environmental review.
  • Final design drawings and specifications for collection system rehab.
  • Bid assistance.
  • Construction phase services.
  • Onsite Resident Project Representative for the year-long project.
  • Easement, permitting, survey, and mapping assistance.


  • CIPP Rehab:
    • Cured in place pipe (CIPP) sewer rehabilitation: 3,200 feet of 48-inch, 3,100 feet of 24-inch, 1,400 feet of 15- and 16-inch, 400 feet of 12-inch, 5,700 feet of 8-inch sewer.
    • Reinstatement of approximately 130 service laterals.
  • Manhole Rehab:
    • Approximately 722 defects (hole/ crack, pipe connection, joint & chimney); 8 rebuilding bench and invert; 32 removing roots; 20 manhole inflow dish inserts; 75 raising manhole frame; 59 removing/resetting manhole frames and covers; 9 replacing standard manhole frames and covers; 107 replacing watertight manhole frames and covers; and approximately 42 point repairs, ranging in size from 6-inch to 24-inch diameter pipe.
    • Approximately, 30 sewer lateral repairs via trimming tap, chemical grouting, and CIPP/T-Liner.
  • Replacement/Installation:
    • Replacement via open cut: Approximately 40 feet of 8-inch-diameter gravity sewer and 1,700 feet of 18-inch-diameter gravity sewer with 24-inch diameter gravity sewer.
    • Installation of approximately 1,800 feet of 10-inch-diameter gravity sewer via open cut, approximately 270 feet of 12-inch-diameter gravity sewer via open cut, and approximately 140 vertical feet of new precast manholes.
Project Description

Pursuant to a Consent Order from TDEC, the City of Chattanooga retained CTI to perform an evaluation of three subbasins in the Hixson area. Included in the scope are over 239,000 LF of pipe from 8 to 48 inches in diameter plus over 1,450 manholes. CTI subcontracted with Compliance EnviroSystems for the SSES field services. Coordination, design, and construction phase services (administration and site) are provided by CTI.

Project Details
  • Client: City of Chattanooga, Tenn.