Expert Panel Meeting Reveals Opposing Visions on N Fertilizer Limits
By Jane Sooby
As the California State Water Resources Control Board (State Water Board) inches toward regulating surface and groundwater pollution by agriculturally-sourced nitrogen, the regulatory framework continues to evolve.
The Second Statewide Agricultural Expert Panel for the Irrigated Lands Regulatory Program (ILRP) met for Day 1 of its “Kick Off Meeting” on Friday, August 8, 2025 at the Cal EPA Building in Sacramento and via Zoom. After Karen Mogus, Chief Deputy Director of the State Water Board, opened the meeting, the expert panelists, all University of California-based scientists and Cooperative Extension specialists, introduced themselves. See list below.
State Water Board staff then provided an overview of the ILRP, the reason that the panel was convened, and the questions it is charged with addressing. In summary, the ILRP is the state’s legal framework for regional “agricultural orders,” which regulate pollutant discharges from irrigated agriculture. The first ILRP Expert Panel was convened by the State Water Board in 2014 to evaluate nitrate control programs and develop recommendations to protect groundwater quality. The first Expert Panel’s report outlined, in the panel’s words, “a comprehensive regulatory program that is proactive.” This report informed the State Water Board’s direction to the nine regional water quality control boards on what can and cannot be included in their ag orders. (However, the State Water Board did not adopt the Expert Panel’s top policy recommendation, to impose a fee on fertilizer purchases. Agricultural fertilizers continue to be exempt from state sales tax in California.)
An agricultural order released by the Central Coast Regional Water Quality Control Board in 2021 contained, among many other provisions, numeric limits for applied nitrogen (N) and for the difference between applied N and removed N: A-R. In response to petitions filed against the order, the State Water Board issued an order finding parts of the Central Coast order incompatible with precedents they’d previously established and remanded portions of the Central Coast order, including the numerical limits, back to the regional board for revision. The State Water Board also stated its intention to convene a second expert panel to review data gathered to date and make updated recommendations for the ILRP.
To this point, the meeting was straightforward. The first rumblings of controversy started with comments made by panelists presenting Third Party Perspectives. The first two panelists, Tess Dunham and Abby Taylor-Silva of the law firm Kahn, Soares & Conway representing the Ag Partners, argued that convening the second expert panel now is premature because insufficient data has been collected to assess the program’s effectiveness and more time is needed to determine realistic N discharge targets. They also questioned whether numerical limits on N discharges are necessary and presented results of an economic analysis that found $119 million-$683 million in lettuce production losses annually and 2,000-11,340 jobs lost under two discharge limit scenarios. They stated that multi-cropping cycles on the Central Coast would not be able to continue under discharge limits and most agriculture in the region, which includes the Salinas Valley, would go out of business. They also argued that the questions asked of the panel are inconsistent with the order establishing the panel.
In contrast, environmental justice-aligned panelists Kjia Rivers, Community Water Center, and Rosa Carrillo Orozco, San Jerardo Cooperative, claimed that the state has delayed imposing limits on N contamination of groundwater with devastating health and economic impacts on impacted communities. They called for the panel to establish limits on N fertilizer application rates and discharges and provided data on the rising incidence of nitrate contamination of well water in the Central Valley, the negative health impacts of this contamination including blue baby syndrome and an array of cancers, and economic impacts on people in these communities who must purchase bottled water and continually drill new drinking water wells.
Nat Kane of the Environmental Law Foundation traced the timeline of California’s “history of inaction” beginning in 1964, when nitrates above safe levels were measured in Delano’s groundwater. A turning point occurred in 2012, when the UC Davis Nitrate Report, authored by Thomas Harter et al., documented the scope of the contamination problem and predicted its worsening if not addressed. Since then, numerous iterations of ag orders have been approved by regional water boards, but none impose sanctions on farms that are identified as over-applying N. Kane pointed out that “the non-regulatory approaches employed so far have not addressed the issue” and that high levels of N discharges are still occurring.
Patrick Pulupa, Executive Officer of the Central Valley Regional Water Board, was invited to comment on the expert panel’s charge and said, “Beneficial use is, at the end of the day, what the regional board has to protect. If groundwater is designated as supporting the municipal supply, which in the Central Valley it is, growers have to protect water quality.”
During the public comment period, numerous Central Valley residents testified, many of them in Spanish, about the negative health impacts they and their families have experienced as a result of their water being contaminated with nitrates, including cancer, hydrocephalus, and skin conditions. One commenter expressed her concern for animals living in the streets who have no choice but to drink contaminated water. They all called for the expert panel to establish limits on nitrate discharges.
Marty Farrell of the California Coastkeeper Alliance testified, “Enforceable limits are essential” and pointed out that it’s been 13 years since California declared the Human Right to Water.
In addition to hearing presentations and public comment, the Second Expert Panel completed administrative tasks including approving the panel’s charter and electing Daniel Geisseler as the panel’s chair.
Day 2 of the “Kick Off Meeting” of the Second Expert Panel will be held Thursday, August 14, 10 am – 4 pm at the Sacramento State University Downtown Campus First Floor Meeting Room. Spanish translation will be provided.
The meeting will feature presentations on Indigenous land stewardship and food systems and available data sources from the State Water Board, Regional Water Boards, Agricultural Coalitions, and Nongovernmental/Environmental Justice Organizations. Attendees can join in person or online via Zoom.
For additional information and to register for the Zoom stream or to make public comment, visit https://www.waterboards.ca.gov/water_issues/programs/agriculture/2025-expert-panel.html
The Second Expert Panel is scheduled to have additional formal meetings October 31, 2025 and January 14, 2026. They will hold a public listening session October 1, 2025 and in November, date TBD. They also plan to convene small group discussions, yet to be announced.
The expert panelists are:
- Ngodoo Atume, SGMA Technical Assistance for Small Farms Coordinator, University of California Sustainable Agriculture Research and Education Program
- Dr. Michael Cahn, Irrigation and Water Resource Advisor, University of California Cooperative Extension Monterey County
- Dr. Ruth Dalquist-Willard, Interim Director, University of California Sustainable Agriculture Research and Education Program
- Dr. Daniel Geisseler, Assistant Cooperative Extension Specialist, Department of Land, Air and Water Resources, University of California Davis
- Dr. Thomas Harter, Distinguished Professor of Subsurface Hydrology, University of California Davis
- Dr. Ali Montazar, Irrigation and Water Management Advisor, University of California Cooperative Extension Imperial County
- Richard Smith, Vegetable Crop Production & Weed Science Farm Advisor, University of California Cooperative Extension Monterey County – Emeritus
- Dr. Hannah Waterhouse, Assistant Professor of Agroecology and Watershed Ecology, Environmental Studies Department, University of California Santa Cruz
