State Water Board and UCLA summarize Phase 1 of statewide wastewater needs assessment

The State Water Resources Control Board received a July 16 update on the statewide wastewater needs assessment contracted to UCLA after a 2022 Board resolution that authorized a multi‑year $4,000,000 contract. Danielle Jimerson, senior engineer with the Board’s Division of Water Quality, summarized Phase 1 work and said the report was completed for internal review on June 30, 2025. "Phase 1 laid the foundation for a statewide wastewater analysis, develop[ed] data methods, launch[ed] a survey, and identify[ed] data gaps," Jimerson told the board.

The assessment matters because it aims to identify systems that are not adequately treating or conveying wastewater, prioritize underserved and disadvantaged communities, and estimate costs and solutions that could guide future investments tied to the Board’s human‑right‑to‑water obligations. Greg Pierce, principal investigator for the UCLA team, told the board the project’s goals include identifying solutions and motivating investment to support safe, affordable sanitation and to implement the human right to water in line with Assembly Bill 685.

Phase 1 accomplishments, as presented by UCLA and partner universities, included: a statewide baseline survey led by UC Davis and UC ANR; a wastewater facility and system inventory compiled by Sacramento State’s Office of Water Programs; and a predictive model developed by the University of Massachusetts to estimate parcel‑level presence of on‑site wastewater systems where official records are sparse. The project organized systems into three permit categories for assessment — NPDES (surface discharge), WDR (land discharge), and sanitary sewer collection systems under the general SSO framework — and the team reported roughly 2,657 systems across those categories for initial screening.

UCLA described a two‑step analytic approach: (1) define and score ‘‘inadequacy’’ using permit compliance, open enforcement orders, and monitoring/reporting failures; and (2) score risk of becoming inadequate using about 25 socioeconomic, operational, environmental and public‑health indicators. The team said it will use those outputs to identify systems that require technical solutions. Pierce emphasized that the model will estimate solution costs only for systems judged inadequate, not for every system statewide.

Speakers and participants raised several operational issues. Board members pressed whether under‑enrollment in regulatory programs could leave collection systems off the inventory; Office of Enforcement staff said they had identified under 50 systems that failed to re‑enroll in a recent sanitary sewer order. Regions also noted overlapping permits where facilities may hold both NPDES and WDR permits; the project reported it had matched permit records to avoid double counting but acknowledged complexity in communicating results where permit types overlap.

Community stakeholders and advisory‑group members participated. Commenters urged the project to include interim assistance for low‑income households on septics (pumping, overflow response), and to allow community groups to submit on‑site system data to improve the UMass predictive model. The California Association of Sanitation Agencies, represented by Jared Bridal (director of regulatory affairs), praised the broad, collaborative effort and encouraged transparency and timely distribution of draft materials to the advisory group.

Project timeline and next steps: Phase 2 will run through 2027 and will produce a public list and mapped tools identifying inadequate and at‑risk systems, recommended technical solutions at the system level, system and statewide cost estimates, and likely funding gaps. Staff said the team will continue advisory‑group meetings and monthly office hours for practitioners.

Speakers relevant to this article - Danielle Jimerson, Senior Engineer, Division of Water Quality, State Water Board (government) - Greg Pierce, Principal Investigator, UCLA (academic) - Jared Bridal, Director of Regulatory Affairs, California Association of Sanitation Agencies…