Aqueduct Protection Program
In support of the San Diego County Water Authority’s Capital Improvement Program is the Aqueduct Protection Program (APP). Initiated in 1990, the APP monitors the service life of the Water Authority’s water-distribution infrastructure, so it can be repaired or replaced before it fails. The APP monitors, tests, and inspects more than 300 miles of water distribution pipelines and more than 2,000 corrosion-control cathodic protection test points to help ensure water keeps flowing throughout the region.
During the scheduled inspections, Water Authority and member agency staff members work together to shut-down and drain strategic sections of the Water Authority’s pipeline distribution system. Then, Water Authority staff members enter the pipeline and carefully inspect it. When deterioration is discovered, the affected sections of pipe may be replaced or rehabilitated using a pipeline relining steel liners or Urgent Carbon-Fiber wraps, which will bring the segment of pipeline back into service and extend its service life.
Water Authority staff diligently inspect a segment of an underground pipeline.
The Water Authority’s pipeline distribution system contains 82 miles of prestressed concrete cylinder pipe (PCCP), of which 27 miles have been rehabilitated with steel liners. The remaining 55 miles of unlined PCCP will be fitted with a state of the art, early-warning acoustic monitoring fiber optic cables within their interior until they can be relined, as part of the Water Authority’s Pipeline Relining Program. The cables monitor the pipeline 24-hours per day and can detect evidence of deterioration, even as water flows through the pipeline. The acoustic monitoring cables are expected to be installed within the remaining portions of unlined PCCP by 2011.
Acoustic monitoring cables are expected to be installed within the remaining portions of unlined PCCP by 2011.
Corrosive soils throughout the county place stress on the underground pipelines that deliver water to the region. To counter-act the corrosion and protect the pipeline, numerous easily corrodible pieces of metal are connected to the pipeline at various points along the pipeline’s length, serving as sacrificial anodes.
Sacrificial anodes are pieces of metal that are intended to be dissolved or “sacrificed” to protect other metallic components that gradually become worn through the loss of electrons to a corrosive surrounding. By connecting the sacrificial anodes throughout the length of a pipeline, corrosion is prevented and redirected to the sacrificial anode. The anodes are tested on an annual basis.
This rendering demonstrates how cathodic protection, with the use of a sacrificial anode, helps guard against corrosion or deterioration of underground pipe.
Sacrificial anodes such as these help prevent corrosion to the Water Authority’s pipelines.
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