Sewer Rehabilitation Project
Castle Rock Water staff identifies sewer pipes for rehabilitation based on a history of root intrusion, increased annual maintenance and pipe defects identified by closed circuit televised (CCTV) inspection. Sewer pipes with capacity issues are also identified as candidates for replacement with larger pipes. Engineering staff develops plans for rehabilitation based on the severity of the defects found.
Cracked sewer pipes can often be repaired from within by pulling a new liner through the sewer pipe. The in-situ method of cured-in-place pipe (CIPP) lining has been in practice since the 1970s and involves pulling a resin-saturated felt tube into the damaged sewer pipe. The tube is then expanded and cured into a new tight-fitting, joint-less pipe within the existing sewer pipe. CIPP lining can extend the service life of sewer pipes by 50-75 years. Rehabilitation by the installation of a CIPP liner, before the sewer pipe deteriorates is cost-effective, and can be completed with minimal disruption to service and results in less future maintenance.
Severe sewer pipe defects and undersized pipes must be dug-up and exposed in order to complete the repairs. When completed on short sections of pipe, these are referred to as "open-cut point repairs." Sometimes a few critical open-cut point repairs must be completed in advance of CIPP lining a long stretch of sewer pipe.
Woodlands manhole rehabilitation project
In fall 2020, Castle Rock Water began replacing seven manholes on the Woodlands Sewer Interceptor pipeline. The pipeline was constructed over 30 years ago and the concrete manholes had fully degraded due to corrosive sewer gasses. The contractor installed fiberglass reinforced polymer (FRP) manhole "inserts" within the existing sewer manholes. The advantage of this rehabilitation method is that the majority of the existing concrete manhole was replaced with an FRP manhole in its existing location, with minimal removal of the existing degraded manhole. This minimized the amount of overall excavation and construction. The end result is all new FRP manholes that are highly resistant to corrosion from sewer gasses.
Work began in June 2020 with detailed manhole inspections. Construction was substantially completed in January 2021. Final completion will occur with site restoration activities including asphalt and concrete replacement in Black Pine Drive and on the paved trail, and with revegetation of disturbed areas along the roadway and trail. These activities will occur in Spring 2021 and the project will be completed within the original budget.
Phase 1 of this project was awarded to C&L Water Solutions, at a cost of $403,371. Staff is scoping Phase 2 of the project and intends to bid construction in 2021, for rehabilitation of downstream manholes (further west).
No service disruption / some road closures
There will be no disruption in water or sewer service. Construction noise and sewer odors may be experienced by residents during construction, as well as closure of the adjacent trail and some portions of the streets.
Past rehabilitation projects
|2020||Young America neighborhood|
|2016||Castle North neighborhood|
|2014||Castle North and parts of Downtown|