By Jane Sooby
The Second Statewide Agricultural Expert Panel’s Public Listening Session #1 was held October 1, 2025, in Rancho Cordova and via Zoom. The expert panel has been convened to advise the California State Water Board on next steps for the Irrigated Lands Regulatory Program (ILRP) and has already met twice. You can read about the previous meetings here.
The ILRP aims to regulate discharges of pollutants from irrigated farmland. While its original scope includes regulating a wide range of pollutants including pesticides and sediments, the expert panel is focusing primarily on nitrate contamination of surface and groundwater from nitrogen (N) fertilizer applications and specifically on the regulatory value of the metrics N applied (A) and N removed (R).
As at previous meetings, contradicting perspectives on water quality data were a major theme of the session, as was the cost and difficulty of complying with agricultural orders for farms that differ from the dominant cropping systems in the Central Coast and Central Valley regions of the state.
The meeting opened with staff reviewing the panel’s purpose and process, timeline, and public input opportunities. Staff emphasized that their goal is to make the panel’s work as publicly accessible as possible.
Staff presented slides summarizing outcomes from the panel’s previous two meetings and encouraged interested parties to refer to the panel’s website, which includes recordings of previous meetings and a table of documents that are being collected for the panel’s reference.
The meeting then went into presentations by members of the public who had signed up in advance to share data.
DATA PRESENTATIONS
Eric Morgan, founder of Soil Health Lab LLC, presented data his team has collected since 2010 that shows measurable N carryover into the next season by the previous crop. He reported that broccoli can contribute 200 lb of N/acre, cabbage and cauliflower 150 lb N/acre, and cover crops up to 120 lb N/acre.
Morgan noted that irrigation water can also contribute to the N equation.
Morgan pointed out what he views as a discrepancy in regulatory approaches between the State Water Board and the California Air Resources Board. The State Water Board assumes that any N applied to the crop and not removed in harvest is lost to groundwater, while the California Air Resources Board views agriculture as a potential source of nitrous oxide release into the atmosphere. Morgan stated, “We cannot have growers be accountable for the same pound of N with one body saying it is going down and another saying it’s going out into the atmosphere.” Morgan called for the agencies to get together and resolve this discrepancy.
Next, Elisha Wakefield, Senior Environmental Scientist with the Los Angeles Regional Water Board, gave a presentation on irrigated agriculture in the Los Angeles region, emphasizing how different it is from agriculture in other parts of the state. Wakefield noted that 81% of enrolled parcels in Los Angeles County are owned by local utilities and are sited in utility corridors, narrow areas beneath power lines, that are leased from power companies by mostly non-traditional farm types including nurseries, cut flower farms, sod farms, and U-pick operations. She described the A and R reporting challenges for these operations including lack of crop coefficients for nursery plants, how to account for R when both the plant and the potting soil are sold into market, and standard measures of crop production (bunches, stem numbers, square feet of sod) being difficult to translate into crop yield reporting.
Wakefield observed that the Los Angeles regional agricultural order has been in place for only two years and that analysis of the limited A and R data so far collected risks being incomplete and skewed. Water nitrate data collected by the discharger group between 2018-2022 revealed no widespread trends of increased groundwater N in the region.
Wakefield concluded by saying that the state’s precedential requirements created significant monitoring and reporting burdens without demonstrating that they’re needed in their area. She suggested that future regulations should allow for more regional flexibility to address local issues and accommodate small and highly-diversified operations.
Next up was Sarah Lopez with Preservation, Inc., the third party in the Central Coast region that conducts water monitoring and reporting for enrolled growers. Lopez took issue with the notion that setting numerical N application and discharge limits are the most effective way to encourage compliance with the ag order, noting that Preservation, Inc. sees high levels of compliance by implementing “soft consequences” including notices, education and training, and increased monitoring/reporting. She provided an example of an enforcement action taken by the regional water board for a reporting violation–not a discharge violation–that resulted in a fine that amounted to 39% of the ranch’s annual revenue, terming this level of fine as an “operation-ending consequence” due to the low margins of return over costs in farming.
Lopez also pointed to the difference between the 50 lb N/acre A-R value that the Central Coast Water Board determined to be water-protective and the (likely higher) A-R value that is feasible for commercial agriculture in the region to remain viable. Lopez encouraged the expert panel to “mind the gap” when considering numerical limits.
Next, Ken Miller of Formation Environmental, a soil scientist and agronomist working on ILRP and CV Salts in the Central Valley region, presented a response to the “Scientific Literature Review for Questions Posed to the Upcoming Second Statewide Agricultural Expert Panel” that was submitted to the State Water Board by environmental and social justice advocates when the questions for the expert panel were being determined. The literature review was also the basis for a presentation made by Daniel Rath, a soil scientist with the Natural Resources Defense Council, at day 2 of the panel’s kickoff meeting.
Miller expressed appreciation for the literature review’s examination of regulatory programs in other countries and also pointed out that there are significant production and economic differences between agriculture in California and agriculture in those regions. Specifically, row crops rather than specialty crops are predominant in the countries mentioned in the literature review. Also, many of the countries cited offer routine subsidies to farmers, while support for specialty crop growers in California is limited to specific cost-share programs and crop insurance.
Miller noted that N application regulations in Denmark have been well-studied and show that when fertilizer application limits were implemented, water quality improved but crop quality and value declined. Also, requiring water-protective practices–such as planting catch crops that absorb excess N left in the soil–increases grower production costs.
Miller ended his presentation by sharing how the Central Valley region’s Groundwater Protection Program builds community understanding of N-loading “values” and “targets.”
The next presentation focused on a critique of the statement made by Eric Warren, Program Manager for the Central Valley region ILRP, at day 2 of the panel’s kickoff meeting that the region has shown a 30% reduction in the metric A-R (nitrogen applied minus nitrogen removed) since 2019, even without implementing enforceable numeric limits.
Jake Dialesandro, Water Justice Science Fellow, California Rural Legal Assistance, Inc. and Lecturer, Santa Clara University, claimed that the data had been “cherry picked” and that when data from 2018 were included in the analysis, the reduction in A-R was only 12%. Dialesandro pointed to data gaps and decreases in township reporting over time including an 8% drop in townships reporting in 2021-2023.
Iris Stewart-Frey, Water Resources Professor, Santa Clara University, summarized their critique by saying that data are insufficient to estimate regional changes in the A-R metric and that this should not be used as justification for not setting numerical application and discharge limits.
In response to Diaslesandro and Stewart-Frey’s comments, Adam Laputz, Assistant Executive Officer of the Central Valley Regional Water Board, stated after public comment was complete that Warren presented data from the perspective of the regional board. They omitted 2018 data because it was incomplete. Laputz observed that even such a seemingly simple metric as A-R is difficult to evaluate and understand and that determining limits will be complicated. He stated, “We all want to see water quality get better” and characterized the water board’s considerations as “Is this measurement protective of water quality? Is this measurement achievable?”
The final data presentation of the day was from U.S. Department of Agriculture Agricultural Research Service (USDA-ARS) Research Horticulturist Eric Brennan, who had anticipated the federal shutdown that began the day of the meeting and so sent in a video of his comment. In his recorded comment, Brennan presented results of numerous studies he has conducted at the USDA-ARS research station in Salinas specifically on cover cropping in vegetable production.
Brennan stated that the nitrogen footprint of high-input vegetable production in the Central Coast region is quite large and that we must work to reduce its size. He noted that a one-size-fits-all approach will not work well in California because of the many different types of cropping systems across the state.
Brennan presented graphs of soil nitrate levels across the course of a year of coastal vegetable production, showing a dramatic decline between the months of November and January when rainfall is washing N from the soil–and presumably into groundwater–because most fields in the Salinas Valley are left in bare beds. Brennan has found that non-legume winter cover crops are a good solution to this problem because they act as a sponge that absorbs excess soil nitrate. He presented data from studies conducted in California and results of meta-analyses (which analyze multiple studies) that all conclude non-legume cover crops can reduce N leaching.
Brennan reviewed the rationale for the cover crop N scavenging credit (Rscavenge), which he was instrumental in creating when the Central Coast Regional Water Board was finalizing its Agricultural Order 4.0 in 2021. A key part of Rscavenge, originally contributed by Brennan, is the C:N ratio of the cover crop shoots, which needs to be at or below 20:1 to avoid the risk of N leaching from cover crop residue.
The Central Coast water board accepted Brennan’s reasoning for the Rscavenge credit and included it in Ag Order 4.0; however, this and other elements of the order were remanded by the State Water Board in 2023 as being inconsistent with its earlier, precedential order. Brennan expressed disappointment with this outcome and noted that for the brief period that Ag Order 4.0 was in place, he’d seen increased interest in cover crops by Salinas Valley growers and increased scientific research on cover cropping. Brennan concluded by offering his assistance to the expert panel.
PUBLIC COMMENTS
The listening session then pivoted to briefer, 3-minute comments. Nineteen people including technical assistance providers, growers, and environmental/social justice advocates offered comments that continued to reveal the stark contrast in opinion between those who feel that data collected to date is insufficient to determine whether enforceable N application and discharge limits should be set and those who feel that the state has already waited too long to establish such limits.
Other concepts presented during public comment included:
- Many people advocated for keeping Rscavenge (the non-legume winter cover crop credit)
- Many people spoke in favor of developing an alternative compliance pathway for small and diversified operations, pointing out that this is allowed under the State Water Board’s precedential order.
- Regional boards should have some stability in requirements so growers aren’t chasing moving targets.
- N monitoring is valuable and can also be a burden on growers.
- Continued investment in innovative cover crop research is important.
- Field-level acreage data is needed from the Central Valley region to link N discharges with specific locations.
- ILRP can complement other state regulations such as the upcoming revision of the Central Valley region dairy order, which may increase compost availability, use of which can be incentivized by retaining the compost credit.
- The uniqueness of the nursery industry and challenges they have with N applied and removed.
The next expert panel listening session has not yet been scheduled but is expected to be held in late 2025 or early 2026.
