T.E. Roberts to replace pipelines for RMWD
Last updated 9/20/2020 at 9:32pm
The Aug. 25 Rainbow Municipal Water District board meeting included the award of two pipeline replacement contracts to T.E. Roberts.
The company based in Orange was given a $280,399 contract for the Sagewood Road pipeline and a $301,734 contract for the Nella Lane pipeline. The two contracts were awarded on separate 4-0 votes with Helene Brazier abstaining from both.
Many of Rainbow’s pipelines were originally constructed within easements, alleys and other locations which are difficult to access. Those access obstacles make maintenance more difficult and pipe failures more costly.
Rainbow has plans to relocate pipelines from those areas to more typical locations such as roadways, and the district is also working on managing high water pressure in the system so some of the pressure issues can be resolved with new pipe configurations connecting to different pressure zones.
In January 2018, Rainbow completed the Water Pipeline Condition Assessment which created a model to prioritize existing pipelines for rehabilitation and replacement based on likelihood and consequence of failure.
In October 2018, Rainbow’s board awarded a design contract to Omnis Consulting Inc. for Pipeline Upgrade Project 1 which consists of Sagewood Road, Disney Lane, Eagles Perch and Via Vera north of West Lilac Road. Those segments will be bid individually, and Omnis has completed the design of the Sagewood Road water pipeline improvements.
Pipeline Upgrade Project 2 consists of the Nella Lane, Via Monserate, Rice Canyon Road, Tecalote Drive, North River Road, Rainbow Glen and Thibodo pipelines.
A 4-0 vote, Jan. 28, with Brazier absent, awarded Harris & Associates Inc. the design contract for the Pipeline Upgrade Project 2 replacements and rehabilitations. Harris & Associates has completed design of the Nella Lane water main replacement project.
The Sagewood Road pipeline will construct approximately 633 feet of 12-inch diameter polyvinyl chloride plastic pipe along with associated appurtenances including a new fire hydrant and an air release and vacuum relief assembly.
“That one is to abandon the old line and replace it with a new line,” Tom Kennedy, general manager of Rainbow, said.
The existing 12-inch pipeline near Sagewood Road and Dentro De Lomas Road was constructed in 1958. The tar-wrapped steel water pipeline is no longer active due to needed repairs. The physical location of the pipeline is on an easement, which is not aligned with the roads.
The Sagewood Road pipeline allows looping in the Morro pressure zone, thus retaining service even if a portion of the pipeline is shut down, by connecting the pipeline in Dentro De Lomas Road to the pipeline in Little Gopher Canyon Road.
Rainbow staff identified a new location for the pipeline which is aligned with Sagewood Road and obtained the necessary easements along the route. The new pipeline will serve the same hydraulic purpose for the distribution system as the pipeline which will be replaced, but the new pipeline’s location within a roadway will allow for easier access and maintenance.
The replacement with PVC pipe makes the pipeline less vulnerable to corrosion as well as less expensive to construct.
The Nella Lane pipeline project will construct approximately 90 feet of 8-inch diameter cement mortar lined and coated steel pipe and 560 feet of 8-inch diameter PVC pipe along Nella Lane.
The work will also include associated appurtenances such as water services, fire hydrant assemblies and automatic air release and vacuum relief valves. The existing 660-foot segment of 8-inch cement CML&C steel water pipeline on Nella Lane will be abandoned.
The existing Nella Lane pipeline was constructed in 1979 and has been identified as a high-priority pipeline for replacement in Rainbow’s Water Pipeline Condition Assessment. The pipeline is located within the roadway on Nella Lane and received a high project risk score because of its recent break history, its location in highly corrosive soils and its high pressure.
Rainbow is in the process of constructing a pressure reducing station near the intersection of Nella Lane and Gopher Canyon Road in order to reduce the pressure of the pipeline on Nella Lane. The addition of a pressure reducing station makes it feasible to construct the majority of the replacement pipeline using PVC pipe.
“The residents won’t have to deal with water pressure in excess of 250 psi (pounds per square inch),” Kennedy said. “When we reduce the pressure, we can replace the pipeline with a PVC plastic which won't be susceptible to corrosion.”
Rainbow advertised the construction portion of the Sagewood Road pipeline project to bid July 23. The construction contract for the Nella Lane pipeline was advertised for bid Aug. 7. The engineer’s estimate was $425,000 for the Sagewood Road pipeline and $350,000 for the Nella Lane pipeline.
On April 28, Rainbow’s board awarded T.E. Roberts a contract to construct the transmission line which will serve Olive Hills Estates. That work, which is expected to be complete this fall, will construct approximately 2,550 feet of 14-inch diameter ductile iron pipe along with fittings and approximately 30 feet of 12-inch diameter ductile iron pipe between Olive Hill Road west of state Route 76 and Via Caballero. The presence of equipment nearby allowed T.E. Roberts to bid the Sagewood Road and Nella Lane projects below the engineer’s estimates.
“We’re viewing this as good news,” Chad Williams, acting district engineer of Rainbow, said.
Joe Naiman can be reached by email at jnaim[email protected]