The San Gabriel Valley Municipal Water District (SGVWMD) selected Civiltec to assess the condition of the Devil Canyon-Azusa Pipeline Project (DCAP). The portion of the pipeline includes Segment 1, a 30-inch diameter pipeline that was constructed in 1974 and runs approximately 34,490 feet in length. Civiltec will assess 20,990 feet of Segment 1, which runs east to west across the City of Glendora. This assessment will ensure the continued delivery of efficient and safe water service for residents served by SGVWMD. The DCAP pipeline is considered the backbone of SGVMWD’s operation and transfers the state water project (SWP) to the Main Basin for its member cities. With recent years of below average rainfall, the DCAP importance to the region has grown and an in depth evaluation of its health is warranted.
In preparation for the conditions audit, Civiltec prepared the analysis and determination of appropriate inspection methods for the pipeline and determined that Pipeline Inspection and Condition Analysis Corporation (PICA) will provide proper technologies for verifying the life of the bar wrapped concrete cylinder pipe through state of the art electromagnetic inspection tools. Because the steel pipeline is lined with ¾-inch cement mortar the evaluation of corrosion levels of the steel is hindered by visual and standard resolution electromagnetic inspection tools. Using PICA’s Remote Field Testing inspection tool will provide high resolution pipe wall thickness measurements at intervals of less than 1/8th of inch, and 360 degrees around the circumference of the pipe. As part of the final report from PICA a Failure Risk Analysis will be provided via the third party independent firm Simpson Gumpertz & Heger Inc (SGH), industry leaders in statistical risk analysis of steel pipelines. The statistical risk analysis report will aid in prioritizing piping sections for repair/replacement to allow the development of capital improvements projects management plan.
Using the PICA system tool will require installation of pipe improvements to provide access to the pipeline interior. A total of two new access vaults will be installed along the pipeline alignment and provide permanent access points for periodic electromagnetic inspections of the existing pipeline as part of a regular maintenance plan. The vaults were custom designed by Civiltec to enable removal of the entire vault lid such that the above ground launching apparatus of the PICA system can be connected to the special wye fitting on the existing pipeline.
A complete utility audit will confirm location, size, and depth of the facilities within the project’s geographic scope, which includes, but is not limited to, existing water, sewer, storm drain, gas, telephone, electric, cable TV, fiber optic, and oil facilities. Civiltec will perform a topographic survey of the project limits, provide geotechnical investigations of proposed project locations, locate subsurface utilities, and conduct design team field visits.
To aid in streamlining the construction schedule to minimize pipeline down time, Civiltec prepared prepurchase bid documents to solicit procurement of long lead time piping for insertion into the existing pipeline by a future contractor. Civiltec’s efforts for this project also include preparation of the design and contract documents for contractor bidding, who will make the installment of the access vaults and coordinate with PICA to either perform the inspection as a subcontractor or designate PICA as a third party hired directly by SGVMWD. The contractor awarded this project will be responsible for providing permitting, traffic control and coordination while inspection work is ongoing. Civiltec will provide construction and pipeline inspection management assistance once SGVWMD selects a contractor. SGVWMD considers this project as a pilot project and will be using it as a future template for an inspection management plan of all pipeline segments in its inventory.
Shem Hawes, PE, served as company representative. W. David Byrum, PE, will be Principal-in-Charge. Steven Walker, PE, will serve as lead Project Engineer