California Construction News staff writer
Walsh Construction joined the Carpinteria Valley Water District (CVWD) and the Carpinteria Sanitary District (CSD) to celebrate the groundbreaking of the Carpinteria Advanced Purification Project (CAPP), a landmark infrastructure initiative that will create a drought-proof, locally controlled water supply for the Carpinteria community.
The project represents a major investment in the region’s long-term water security and sustainability. Once completed, CAPP will transform more than one million gallons of recycled wastewater each day into a safe, reliable drinking water supply using a state-of-the-art treatment process that includes membrane filtration, reverse osmosis, and ultraviolet advanced oxidation.
Designed to strengthen the community’s resilience to drought and climate change, the advanced water purification facility will provide a dependable, year-round water source capable of meeting approximately 25 percent of the region’s annual water demand.
“CAPP is a transformational project that will enhance local water reliability for generations to come,” project stakeholders said during the groundbreaking ceremony.
In addition to the treatment facility, the project includes approximately one mile of purified water conveyance pipelines that will transport highly treated water from the facility to the Carpinteria Groundwater Basin, where it will be used to replenish local groundwater supplies.
The advanced purification facility, with a treatment capacity of 1.2 million gallons per day (MGD), will be located at CSD’s wastewater treatment plant. Engineering firm Woodard & Curran was selected by CVWD to conduct the project’s feasibility study and environmental review, as well as provide preliminary and final design services.
The facility’s treatment train includes an equalization tank, microfiltration, reverse osmosis, and an advanced oxidation process. Additional project components include a purified water pump station, approximately 6,100 feet of 10-inch conveyance pipeline connecting the pump station to a well lateral split point, 2,000 feet of 8-inch pipeline extending to two injection wells, and two 14-inch-diameter groundwater injection wells equipped with backwash pumps. The design also incorporates three sets of monitoring wells to support long-term groundwater management and regulatory compliance.
Upon completion, the Carpinteria Advanced Purification Project will capture 100 percent of CSD’s treated effluent that was previously discharged into the Pacific Ocean and instead use it to replenish the Carpinteria Valley Groundwater Basin. By converting a previously discarded resource into a sustainable local water supply, the project will help secure the community’s water future while advancing regional goals for environmental stewardship and water reuse innovation.
As a 50-year investment in local water infrastructure, CAPP stands as one of the most significant water supply projects in the region’s history, ensuring greater water independence and reliability for residents, businesses, and future generations.
