Project 4: Inspection and Assessment Services for the 87-inch Rosecrans Force Main and the West Point Loma 114-inch Interceptor Sewer
| Owner: |
Metropolitan Wastewater Department (MWWD)
The City of San Diego |
| Project Location: |
Rosecrans Force Main and the West Point Loma Interceptor — San Diego, CA |
| Date of Performance: |
Phase A - September 2008
Phase B - October 2008 |
| Services Provided: |
CCTV Inspection and Condition Assessment
Confined Space and SCBA Entry
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The intent of this contract was to inspect and report on the condition of two (2) large diameter sewer pipelines for the Metropolitan Wastewater Department (MWWD). The project was divided into two (2) phases:
Phase A — Inspection of the 87-inch Rosecrans Force Main Siphon
Phase B — 114-inch West Point Loma Interceptor Sewer
Phase A: DownStream Services, Inc. preformed inspection services to determine the condition and structural integrity of the 87-inch Rosecrans Force Main Siphon and appurtenances. The portion requiring inspection was located under the Navy Channel at the Harbor Drive Bridge.
Confined Space and SCBA Entries played an integral part in the success of the assessment process.
Project Challenges: The logistics of this first phase posed several challenges. DownStream Services, Inc. was required to coordinate with NAVFAC SW, SPAWARS, San Diego Port Authority, and the MWWD to gain special access to inspect the pipeline at the four (4) different locations. The extreme environment required DownStream Services, Inc.'s field crews to be suited in appropriate PPE's, with SCBA and attachable gas metering equipment to manually perform the inspection while in the pipeline.
Phase B: The West Point Loma Interceptor Sewer (WPLIS) carries all the raw sewage to the Point Loma Wastewater Treatment Plant. DownStream Services, Inc. was required to perform inspection and assessment services on the 114-inch PVC-lined concrete sewer pipe to determine its condition and structural integrity.
Project Challenges: As with Phase A, DownStream Services, Inc. was required to coordinate with different agencies in order to inspect the WPLIS pipeline. Scheduling with Pump Station #2 and the Navy Pump Station posed an additional challenge. The sewage flow needed to be suspended during the inspection, allowing only two (2) hours to complete the assessment before returning the pipeline into service. Another challenge was the extremely dangerous environment that DownStream Services, Inc.'s field crews had to endure during the inspection process. With the assistance of the MWWD, the contract was modified to ensure the health and safety of DownStream Services, Inc.'s field crews.
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