Coast Trunk Sewer Rehabilitation Project for the Orange County Sanitation District
Paul F. Wilson1 and Robert J. Warren2
1525 Faraday Ave, Suite 290, Carlsbad, California, USA 92008; Email: pwilson@pirnie.com. 1525 Faraday Ave, Suite 290, Carlsbad, California, USA 92008; Email: rwarren@pirnie.com.
ABSTRACT
The Coast Trunk Sewer is about 7,300 meters long consisting of 1,350, 1,800, and 2,100 mm RCP PVC lined pipe. The sewer was built in the early 1980's in Huntington Beach, California to serve a large development that never was constructed and consequently, the flow in the sewer has always been much less than anticipated. Corrosion has occurred to the pipe below the PVC liner that covers only 240 to 270 degrees of the circumference.
This paper presents the procedures and technical memoranda that were developed to inspect and assess the condition of the sewer as well as the approach that was followed to evaluate a number of rehabilitation options and ultimately select the alternative most suited for the rehabilitation. The alternatives included 1) replacing the corroded concrete with cementitious grout and maintaining the original shape of the sewer, 2) filling in the bottom of the pipe with concrete, 3) installing concrete weirs inside the pipe to raise the water level, 4) installing a fiber reinforced epoxy liner over the corroded areas, 5) installing a spiral wound pipe liner, 6) extending the PVC liner with PVC bonded to a cementitious grout resurface, 7) sliplining with HDPE and 8) sliplining with centrifugally cast, glass-fiber-reinforced, polymer mortar (CCFRPM) pipe.
