Corrosion Mitigation Program for Critical Pipelines
Sacramento Area Sewer District, in collaboration with regional stakeholders, is developing the Harvest Water Program (Harvest Water) to meet its long-term goals of increasing the production and use of recycled water. Harvest Water will offer multiple benefits, including providing a safe and reliable supply of tertiary-treated water for agricultural uses, reducing groundwater pumping, supporting habitat protection and enhancement efforts, and providing near-term benefits to the Sacramento-San Joaquin Delta. The program will help Regional San diversify its effluent management options. Harvest Water will provide up to 50,000 acre-feet per year of tertiary recycled water from the EchoWater Resource Recovery Facility (EchoWater Facility) for use in-lieu of pumped groundwater to irrigate crops on permanent agriculture and habitat lands, as well as for ecological beneficial uses in southern Sacramento County.
The project includes the installation of transmission and distribution water pipelines of large diameter to convey water from the EchoWater Facility to the on-farm connections. Key pipelines include the Elk Grove Transmission Pipeline, the Franklin/Eschinger Distribution Pipelines, the West Pipelines, and the Central-South Pipelines. These pipelines are required to be long-lasting assets due to their criticality for water conveyance.
V&A led the design and delivery of the cathodic protection and DC and AC stray current mitigation systems for the transmission and distribution pipelines associated with the Harvest Water program. Through a thorough review of the soil conditions in regard to the corrosivity towards buried steel, investigations on existing foreign utilities including potential sources of stray current (such as overhead high voltage AC transmission towers and buried gas line pipelines), proposed alignments, and materials selection, V&A developed an action plan in the form of a preliminary design report to guide in the most efficient corrosion mitigation and stray current mitigation measures for the project. V&A provided a holistic corrosion mitigation and stray current mitigation design consisting of impressed current cathodic protection systems, AC grounding mitigators systems, and DC grounding systems strategically positioned across the alignments. V&A also provided Engineering Services During Construction including technical assistance, submittal and RFI reviews, and coordination between other engineering disciplines and contractors. Construction is currently ongoing (as of August 2025) and is estimated to be completed by the end of the year.
Key features
- Over 33 miles of dielectrically coated steel pipelines with diameters ranging from 36 inches to 66 inches.
- CP system consisting of deep anode well, impressed current cathodic protection systems working in unison to protect the electrically continuous pipelines.
- Strategically designed DC and AC stray current mitigation systems to address localized corrosion issues.
Outcomes
- (Ongoing) On time and on budget engineering services for the cathodic protection and stray current systems.
- (After Construction completion) Confirmed the effective cathodic protection and stray current mitigation of the Harvest Water Transmission and Distribution pipelines per AMPP/NACE standard practice guidelines.
- (After Construction completion) Provided a plan for effective monitoring and adjustments to the systems for long-term protection.
