Planning Commission approves Carpinteria Advanced Purification Project after extended review and public comment

The Carpinteria Planning Commission on a 4-0 vote approved permits to build and operate the Carpinteria Advanced Purification (CAP) project, a water-reuse system that will treat wastewater to a potable standard and inject up to 1,200 acre-feet per year into the Carpinteria Valley Groundwater Basin for later extraction.

The project, presented to the commission by city planner Brett McNulty, would place the main treatment building and supporting equipment at the existing Carpinteria Sanitary District wastewater treatment plant, add roughly 5,475 feet of buried conveyance pipe and two injection well sites — one in the Meadowview Lane right-of-way and one at Linden Avenue near St. Joseph’s Church — plus monitoring well clusters. The Carpinteria Valley Water District will operate conveyance and injection systems; the Sanitary District is leasing site space at the treatment plant for the advanced treatment facility.

Why it matters: the CAP project is intended to reduce Carpinteria’s reliance on imported supplies and to help stabilize groundwater levels in the coastal basin, reducing susceptibility to seawater intrusion. The project team told commissioners the facility is designed to produce up to 1,200 acre-feet per year (about 1.2 million gallons per day) and could supply roughly one-quarter of the district’s water needs.

Project details and operation Brett McNulty told the commission the AWPF footprint is on a 2.78-acre parcel adjacent to Carpinteria Creek and the existing wastewater plant and includes a main building, a 200,000-gallon equalization tank (clear well), piping and electrical improvements and floodwall extension. Treated water would travel via buried PVC pipelines along Olive and Maple avenues and cross under Highway 101 to Meadowview Lane, where two injection wells and monitoring clusters will be installed. The district will also install a 24-inch buried pipe to store backwash water so the project does not rely on an aboveground backwash tank.

The Carpinteria Sanitary District’s general manager, Craig Murray, described the work as part of climate-adaptation and flood-protection planning: “This is an important project for us,” he said, noting the main electrical feed to the plant sits outside the floodwall and the project would allow vulnerable infrastructure to be enclosed and protected.

Public comments and neighborhood concerns The Planning Commission hearing drew multiple public speakers, many of them residents of the Linden Meadows homeowners association who objected to the Meadowview Lane injection-well location. Scott Grieve, Linden Meadows HOA president, presented a petition signed by 56 residents and asked the commission to deny the Meadowview Lane site, citing notice and process concerns and the effect of nighttime drilling and a 24-foot sound wall on property values. “I would like for the commission to deny approval for development of that injection well site on Meadowview Lane,” Grieve said.

Several neighbors described worries about nighttime noise from 24-hour drilling, possible vibration, lighting and dust. Elizabeth Mandel told the commission she lives “very close to the exact construction site” and said “nonstop noise at 75 decibels … even with a 20-foot sound wall” would disrupt sleep and could cause health impacts. The project team said the 24-hour drilling windows are expected to be limited to about four weeks per well and that temporary hotel relocation assistance may be offered for nearby residents during intensive 24-hour drilling periods.

Monitoring wells and site selection Commissioners pressed the water district on monitoring-well placement and project operations. McNulty and water district staff said that monitoring clusters are required by state regulators and that, per recent project revisions, the monitoring wells that were originally proposed at Meadowview were moved to an agricultural parcel north of Franklin Creek that lies outside city limits and into county jurisdiction. City staff said the monitoring wells must be in place to satisfy regulatory monitoring requirements and that if the county does not approve the proposed monitoring location the district would have to identify and permit an alternate monitoring site.

The district’s presentation emphasized hydrogeologic and regulatory constraints used to select well sites: wells must be within the confined portion of the basin, separated from private wells by regulatory setbacks, located where injection will be recovered by district extraction wells, and accessible for drilling and maintenance. The applicant noted six candidate sites were considered in the environmental review and the chosen locations reflect a balance of those constraints and community input.

Technical, regulatory and financial oversight Commissioners asked who will be responsible for ongoing operation and compliance. City staff and the district said the state’s drinking water and regional water boards regulate water quality and injection permits; the city enforces municipal requirements such as lighting and noise. The district said it will provide proof of required state permits before construction is completed and that the district will adopt mitigation monitoring and reporting to track compliance.

On funding, district representatives said roughly half of project capital is expected to come from grants and low-interest loans. The applicant reported a suite of awards and agreements, including a previously announced $15 million state award (with ongoing state action to backfill a previous adjustment), federal funding from the Bureau of Reclamation (identified in the presentation as roughly $18.3 million), a $1.15 million grant for monitoring wells, and a low-interest state revolving fund loan. The district said it plans to use a combination of grant funds, loan proceeds and customer fees to cover capital and debt service; district staff noted an expected annual debt-service charge of about $2 million that would be collected via a tax roll charge and said estimated residential impacts could be in the hundreds of dollars per year depending on final rate decisions.

Commission action and conditions After public comment and deliberation the Planning Commission voted to adopt resolution PC25-008 and approve the conditional use permit and coastal development permit, and to accept the Carpinteria Valley Water District’s previously certified EIR (State Clearinghouse No. 2019011016, final EIR dated 12/11/2019) and Addendum (October 2024). The vote was 4-0: Commissioner Benefield — aye; Commissioner Lafeverse — aye; Commissioner Allen — aye; Vice Chair Moyer — aye.

The commission and staff discussed additional permit conditions during deliberations. Commissioners requested that the approval be conditioned to require a finalized operating agreement (joint exercise of powers/operations and maintenance agreement) between the Carpinteria Valley Water District and the Carpinteria Sanitary District before construction proceeds, and that the monitoring-well cluster that lies outside city jurisdiction be approved by the relevant county agencies or a suitable alternative monitoring plan be in place before constructing the Meadowview Lane injection well. Commissioners also asked for a post-construction verification that operational noise and backwash cycles at the injection sites do not exceed stated expectations; staff noted existing conditions require the applicant to demonstrate all additional permits and regulatory approvals.

District response on concentrate and treatment Answering concerns about the reverse-osmosis concentrate discharged to the ocean, a district representative said the concentrate is “very much transparent and clear — maybe it’s a little tinted — but you certainly won’t see anything at the ocean surface or coming out of the diffusers,” and that the project would reduce overall discharge volume to the ocean while meeting required dilution analyses submitted to state regulators.

What’s next The project schedule presented to the commission estimates construction beginning in 2026 with an approximately 2 year and 9 month construction period. The commission’s action forwards the matter to the City Council for its consideration of related entitlement steps where applicable, and conditions adopted by the commission require documentation of required permits and the mitigation monitoring program prior to certain construction milestones.

Quotes “We’ve been doing climate change adaptation planning, looking at flood plain issues, and this is a vulnerability for our existing facility,” Carpinteria Sanitary District General Manager Craig Murray said. “We have a floodwall that surrounds the entire treatment plant, but the main electrical feed sits outside that floodwall. So this would allow us to bring that inside and be protected.”

“We would like Meadowview Lane to be free of this,” Scott Grieve, president of the Linden Meadows homeowners association, told the commission, urging denial of the Meadowview Lane injection well site.

Ending Commissioners said they were persuaded by the combination of project benefits to long-term water reliability and the project team’s mitigation commitments, and they voted to approve the CUP and CDP with additional conditions to secure monitoring-well approvals and an operating agreement. The commission’s recorded findings and conditions will be included in the project’s resolution and the city’s file for the permit.