By Jane Sooby
Day 2 of the Second Statewide Agricultural Expert Panel’s “Kick Off Meeting” convened August 14, 2025, at Sacramento State University Downtown Campus. The panel has been convened to advise the State Water Board on next steps for the Irrigated Lands Regulatory Program (ILRP). (Read article on Day 1 here.)
The day was heavy on data. Themes addressed throughout the day included
- whether or not sufficient data exists to move forward with setting nitrogen (N) application and discharge targets and limits
- challenges with interpreting data collected thus far due to discrepancies in how data are reported
- the need to include acreage and location data with N data to be able to calculate field-level results and to independently verify calculations submitted by third parties
- the relative value of the metrics N applied (A) minus N removed (R) [A-R] and A/R
- the need for regional flexibility in monitoring and reporting
The meeting opened with Enrique Salmón, head of the American Indian Studies Program at California State University–East Bay and originator of the concept of “kincentric ecology,” presenting an indigenous perspective on land, water, and food.
Dr. Salmón noted that because indigenous people viewed everything including plants, animals, and water as being related and being on the same level of importance, there is no word in Native languages that expresses the concept of “wild” or “wilderness.” This kinship is the basis of kincentric ecology. He described Native land management practices including controlled burning, pruning, and coppicing.
The rest of the day was devoted to presentations of data and public comment.
State Water Board Data
State Water Board staff started with an overview of their analysis of available ILRP nitrogen (N) data, which the State Water Board required in its order that remanded portions of the Central Coast Water Board’s ag order and established the Second Expert Panel.
Environmental Scientist Kelsey Moore provided an overview of N reporting requirements, select data gathered between 2020 and 2022, and a comparison of N application rates for cauliflower in the Central Coast and Central Valley regions which showed similar rates in both regions with most growers applying within CDFA-recommended N fertilizer rates.
Moore ended by presenting one of staff’s conclusions: that the second expert panel should be convened as quickly as possible while there is still flexibility in how ILRP is structured.
Laleh Rastegarzadeh, Water Resources Control Engineer, shared a table of dates that each regional board adopted their ag order and the data collected in each region. She then described the data and reporting challenges staff encountered when analyzing the data, including
- Data is not in machine-readable format
- Third-party coalitions use 20 different reporting formats
- There is no standardization of crop names, making comparisons difficult
Rastegarzadeh reported that staff are working to complete a data analysis tool that will graph the data for the expert panel.
Read a letter from the Natural Resources Defense Council calling for the State Water Board to supply the Second Expert Panel with sufficient data to thoroughly analyze the ILRP.
Regional Water Board Data
Central Coast Region
Data presentations continued with Mary Hamilton and Elaine Sahl reporting from the Central Coast Regional Water Board. ILRP Program Manager Sahl presented nitrate data from on-farm domestic wells that demonstrate groundwater quality is not improving and that nitrate loading continues to be excessive. Forty-four percent of ranches had at least one well that exceeded the Maximum Contaminant Level (MCL) of 10 milligrams nitrate nitrogen (NO3-N) per liter.
Sahl stated that the Central Coast Water Board has been gathering data since 2012 when Ag Order 2.0 was put into place and that they have “plenty of data,” all accessible through their website.
Sahl said that “Overapplication of synthetic fertilizer is the primary driver of nitrogen loading” and that staff is “Ready for targets and limits to address nitrogen loading in our region.”
Sahl presented a graph of nitrogen applied (A) minus nitrogen removed (R) for lettuce grown in 2024 that included a line indicating the A/R ratio, which is a unitless metric that the State Water Board has put forth as the primary metric for assessing nitrogen discharge levels. The graph shows that A/R does not uniformly reflect N discharge nor inform a grower about the level of loading that is occurring on their ranch.
Displaying a graph showing N fertilizer rates applied to conventional lettuce, Sahl noted that there are areas where growers are over-applying the recommended N levels for the crop.
Sahl then turned her attention to other elements of Ag Order 4.0 that were remanded by the State Water Board, including
- discounts for compost and organic fertilizer applications to account for their slow release of N over time
- credits for N removal practices including N-scavenging cover crops, treatment systems, and others not yet quantified
- incentives including a compliance pathway that does not count N carried in irrigation water in order to incentivize pump and fertilize.
Sahl stated, “A lot of work has gone into these science-based approaches for credits.”
Sahl’s claim that “Overapplication of synthetic fertilizer is the primary driver of nitrogen loading” was later challenged by Sarah Lopez of the Central Coast region’s third party, Preservation, Inc., who cited the example of a grower who had to apply fertilizer multiple times after sequential storms leached the applied N, requiring re-application. “In the grower’s mind, they’re not overapplying,” she said. “They’re trying to meet crop needs. Now that we’ve called their attention to that, they can manage that in a future season.”
Central Valley Region
Eric Warren, ILRP Program Manager for the Central Valley Regional Water Board, presented data collected by coalitions in the region. He noted
- a loss of 100,000 acres enrolled in the ILRP since 2014 as a result of multiple industry pressures
- a 30% reduction in the metric A-R reported since 2019 and a reduction in the average value for A-R from 59 lb/acre to 41 lb/acre
Warren stated that the reduction in A-R reflects a decrease in nitrogen loading to groundwater; however, the reason for this decrease is still not clear and more data are needed from both wet and dry years to understand why this is happening.
Warren concluded by crediting reduced A-R to Irrigation and Nitrogen Management Plan requirements, grower education, data collection, and an “iterative non-point source” approach to reducing N loading without imposing limits.
Expert panelist Ali Montazar asked Warren if the reduced N loading is reflected in water quality measurements. Warren responded that a regional collaborative is collecting groundwater data and so far the impacts are not showing up in the groundwater samples. He noted that it will take many years before the reduced N loading is visible in groundwater quality and that water quality measured now is “reflective of farm practices many years ago.”
San Diego Region
Next, Kaylee Popovich, Environmental Scientist, and Cole Rodriguez, Water Resource Control Engineer with the San Diego Regional Water Board, presented data on the farming operations in their region. They requested guidance from the expert panel on alternative compliance methods because the precedential requirements for the ILRP are not a good fit for the many small-scale, highly diversified operations there.
Approved Third-Party Program Data
Central Coast Region
Sarah Lopez, Executive Director of the Central Coast region’s third party Preservation, Inc., reported that 93% of ranches so far meet the Ag Order 4.0 target of A-R= 500 lbs/A and 54% meet the target of A-R=200 lbs/A. She described Preservation, Inc.’s procedures for gathering data from their farmers including phone calls to follow up with those whose numbers are above or below average to verify their information. Lopez stated that it takes “at least three rounds of contact events before 90% of our growers understand that there are new requirements.”
Lopez noted, “There’s a lot of grumbling and complaining about the forms and navigating GeoTracker” and that the regulatory system is particularly difficult for growers who are elderly, lack a college education, or speak a language other than English.
Lopez was the only presenter to break out data on use of organic fertilizers and compost, noting that plant available N was 71% and 5% of the amount applied, respectively, with the balance being held in the soil matrix and available for remineralization by subsequent crops.
Lopez observed that high N in irrigation water may drive the high A-R report. She also observed that outliers almost always result from an error in entering the data.
Lopez raised a number of unanswered questions about targets and limits including whether they would be implemented on the basis of crop or land unit and if they would be determined based on protectiveness versus feasibility.
Central Valley Region
David Cory, a farmer and attorney with the Central Valley Salinity Coalition, presented data from the Central Valley region gathered by 14 coalitions. He described the data gathered and shared an image of the summary report template that is filled out after harvest. Yield data are used as a surrogate for the N removed metric (R).
Cory described a Groundwater Protection Program (GWP) Formula developed by 13 coalitions to determine GWP values and targets for high-priority townships that integrates two models, CV-Soil and Water Assessment Tool (SWAT) and CV-Non-Point Source Assessment Tool (NPSAT). He also described how ILRP connects with the nitrate control portion of the CV-Salinity Alternatives for Long-term Sustainability (CV-SALTS) Salt Control Program.
He reviewed the outreach and education that the coalitions use to communicate with growers and shared an example of a graph they send to every grower showing where they land on the A/R curve relative to the majority of growers.
Cory pointed out that areas that already have elevated levels of nitrates will take decades to remediate even if growers were to end N use today.
Colorado River Region
Melissa Turner, President, MLJ Environmental, presented data gathered in the Colorado River Region which includes Imperial and Coachella valleys. Turner noted that the region is in an early stage of regulation compared to other regions. Echoing an issue raised by presenters from the San Diego region, Turner said that reporting is challenging for small farms that grow a diversity of crops and that growers feel they’re forced into a one-size-fits-all regulation that was designed for other regions. She gave the example of the Imperial Valley, where the groundwater in most of the region is too salty to grow crops so growers only can irrigate with surface water.
Another challenge for growers in the area is that, to date, only three coefficients have been developed for the many crops grown in the region. Coefficients are crop-specific multipliers that calculate the amount of N removed (the metric R) by a given crop yield.
Turner concluded that there are insufficient data to set enforceable limits and that regional differences require site-specific approaches instead of blanket policies.
NGO and Environmental Justice Program Data
Iris Stewart-Frey, Water Resources Professor, Santa Clara University, and Jake Dialesandro, Water Justice Science Fellow, California Rural Legal Assistance, Inc. and Lecturer, Santa Clara University, presented an analysis of data that they argue support science-based N application and discharge limits. The data, gathered from state water board, CV-SALTS, Central Coast and Central Valley regional data, shows
- N pollution continues to worsen, disproportionately affecting disadvantaged communities
- There is a statistically significant, positive relationship between N discharge as measured by A-R and N concentrations in groundwater wells
- Sufficient data exists to set science-backed N application and discharge limits
They offered recommendations for data reporting including standardizing reporting, follow up on inconsistent reporting, and reporting acreage data.
The final presenter was Daniel Rath, Soil Scientist with the Natural Resources Defense Council, who presented information on N application and N discharge limits in other regions including the European Union and New Zealand. Among other findings, he reported that N discharge limits have improved EU surface and groundwater quality at the same time agricultural output has increased.
Public Comment
Most commenters represented environmental justice organizations or communities impacted by high nitrate levels in their groundwater supply. They stated that sufficient evidence exists to set N application and discharge limits and also supported public release of acreage data.
Christopher D’Aiuto of Provost & Pritchard Consulting Group raised a number of issues and concluded by saying that agriculture cannot solve the problem of groundwater nitrate contamination alone, that a basin-wide, all-discharger approach is needed.
