CCP 07-14-1997 - Laserfiche WebLink

Home Browse Search

. - . . . Mr. Dwayne Stafford .. July 9, 1997 Page 2 . the work. With "test and seal", a combination packerltelevision unit is pulled to each joint. The packer is inflated to isolate the joint and air pressure is applied to 'test" the joint. If the joint fails to hold air pressure, a grout sealer is injected into the joint and allowed to cure. After curing, the . joint is retested until it passes an air test. Then the packer unit is moved to the next joint. With the difficult access, it may not be possible to do a test and seal program, but a flexible liner may be appropriate as an alternative. The cost of lining a pipe may be two or more times that of testing . and sealing in normal cases. However, in this situation with access issues complicated we would anticipate that the costs will be closer together. Preliminary estimates suggest that the cost to slipline the 1,700 feet of pipe in this area may be about $120,000. . Flow records are not available to measure the amount of Infiltration and Inflow (Ill) in this line but it is estimated that the joint leaks and leaking manholes contribute about 2.5 million gallons of flow per year to the line. During periods of higher ground water levels the flow rates may be somewhat . higher. Valentine Park Easement . This area includes approximately 2,255 feet of 15 inch RCP, 1,775 feet of 12 inch RCP, 614 feet of 12 inch vitrified clay pipe (VCP), 300 feet of 8 inch VCP, and 23 manholes. 'e The pipe structure appeared to be sound in the area between County Road E-2 and the railroad tracks. The condition was fair to poor in the north segment from Old Highway 10 to the lift station. . Where the structure was good, there were numerous leaking joints and joints with mineral deposits. It appears that much of the sewer in this area was installed below the normal groundwater to level so infiltration will be in continuous problem throughout the year. Only 3 manholes were noted as . leaking but in consideration of the groundwater conditions, additional manhole leakage is probably occurring. . In the northern section where the structure was poor, there were significantly fewer leaks observed but there was heavy root intrusion and some significantly cracked pipe. The roots prevented complete viewing of the segments so there may be additional defects that were not observed. . In the southern section a test and seal program would be appropriate, but access is also a problem so insertion of a flexible liner will be considered as a viable option. As previously described, the . cost of sliplining may be reasonable in comparison to test and seal due to site conditions. In the northern section the sliplining would be appropriate to correct the pipe cracking and root intrusion problems. Using the same unit cost as previously stated, the estimate for sliplining both the . northern and southern segments in this area would be about $340,000. The southern section of the area showed some potential for continuous III at an estimated rate of I about 2.4 million gallons per year. During periods of more severe groundwater presence, the rate may be higher. .. In the northern section the sliplining is intended to improve structural conditions and reduce maintenance needs, the I{I reduction benefit will probably be minimal. Howard R. Green Company . CONSULTING ENGINEERS