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By Joe Naiman
Village News Correspondent 

CWA ratifies emergency declaration for Moosa Canyon pipeline repair


Last updated 8/30/2019 at 6:46pm

A leak on the San Diego County Water Authority’s Pipeline 4 was discovered Aug. 2. SDCWA acting general manager Sandra Kerl issued an emergency declaration, which exempts the CWA from the normal contract procurement process and from California Environmental Quality Act review, Aug. 7.

The declaration required ratification by the CWA board at the next board meeting and that occurred on a unanimous vote Aug. 22.

“We can’t not approve this because we need to get this fixed,” Marty Miller said, who chairs the CWA’s Engineering and Operations Committee and who represents the Vista Irrigation District on the CWA board.

Although the emergency declaration allows the CWA to move forward without the environmental review process, the CWA will coordinate with the environmental agencies.

The operating pressure within Pipeline 4 at Moosa Canyon exceeds 300 pounds per square inch, and a catastrophic failure could create considerable environmental damage as well as damage to Pipelines 3 and 5 and to a Rainbow Municipal Water District pipeline in the area.

The CWA’s Second Aqueduct includes Pipelines 3, 4 and 5. Pipelines 3 and 5 provide untreated supply to CWA member agencies while Pipeline 4 distributes treated water to member agency turnouts.

Pipeline 3 is a steel pipe 72 inches in diameter, Pipeline 4 is a pre-stressed concrete cylinder pipe 90 inches in diameter and Pipeline 5 is a pre-stressed concrete cylinder pipe 96 inches in diameter. The pipelines are 40 feet apart from each others’ centers, which translates to 32 to 33 feet apart from each other at their perimeters.

CWA staff observed water discharging from the side slope of Moosa Creek, Aug. 2. When the water was sampled, it was identified as treated water, which ruled out groundwater and narrowed the source to Pipeline 4 or the Rainbow pipeline.

CWA and Rainbow developed a plan to conduct additional investigations to determine which pipeline was the source of the leak, and CWA and Rainbow staff determined that the leak was from Pipeline 4, Aug. 6. Kerl declared an emergency the following day.

Kerl worked with two contractors who have previously provided work on the Second Aqueduct and chose J.F. Shea Construction Inc., whose recent work included relining a portion of Pipeline 5.

Although the cost for the repair work is currently unknown, the CWA has an asset management program which addresses inspection and repair of CWA aqueduct facilities and $1,000,000 is currently available in the asset management program budget.

A shutdown is tentatively scheduled for Sept. 9. Bulkheads will be installed to isolate the pipeline, which will allow for inspection to determine the specific repairs.

“We don’t know what the repair’s going to be, what the direction’s going to be,” Jim Fisher, CWA director of operations and maintenance, said.

Fisher expects the bulkheads to be delivered between Sept. 4 and Sept. 6.

“Once the bulkheads are installed all connections will be back into service,” he said.

The bulkheads will be 9 inches in diameter.

“It will provide a safe work environment,” Fisher said.

The inspection will allow the CWA and J.F. Shea to develop a design for the repairs. That will also allow for a schedule for the pipeline to be returned to service.


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