The Expert Panel process and nitrogen regulation

Dan Munk UCCE Fresno County

December 9-10 2014

Panel Background • SBX2 1 (2008, Perata) required SWRCB to develop pilot projects focused on

nitrate mgt. in the Tulare Basin and Salinas Valley and to report findings of the project including recommendations.

• 15 recommendations in 4 areas: 1. Provide safe drinking water 2. Monitoring, notification and assessment 3. Nitrogen tracking and reporting 4. Protecting groundwater

• Recommendation 14: convene a panel of experts to assess existing agricultural nitrate control programs and develop Recommendations to ensure that ongoing efforts are protective of groundwater quality.

• Certain issues related to impacts of agricultural discharges on surface water.

Role of Panel

• Review the Irrigated Lands Regulatory Program (ILRP). • Evaluate ongoing ag control measures that address nitrate in groundwater. • Evaluate and address other risks to water quality posed by agricultural practices. • Address questions posed by the State Water Board in its order regarding the

petitions of the Central Coast Regional Water Board. • Address questions developed by an Advisory Committee, other agencies and the

public as approved by the State Water Board. • Propose new agricultural control measures, if necessary. • Conduct three public meetings to take public comment. • Write the final report on findings and summary of project discoveries and recommendations. Note: The Panel was given no authority or power to write regulations or

requirements of any nature.

Questions to the Panel 1. How can risk to or vulnerability of groundwater best be determined in the context of a regulatory program such as the Irrigated Lands Regulatory Program (ILRP)? 2. Evaluate and develop recommendations for the current approaches taken to assessing

risk to or vulnerability of groundwater. 3. How can risk to or vulnerability of surface water best be determined in the context of a regulatory program such as the ILRP? 4. Evaluate and develop recommendations for the current approaches taken to assessing

risk to or vulnerability of surface water. 5. What management practices are expected to be implemented and under what

circumstances for the control of nitrogen? 6. What management practices are recommended for consideration by growers when they

are selecting practices to put in place for the control of nitrogen? 7. Evaluate and make recommendations regarding the usage of various nitrogen

management and accounting practices.

Questions to the Panel 8. Evaluate and make recommendations regarding the most effective methods for

ensuring growers have the knowledge required for effectively implementing recommended management practices.

9. What measurements can be used to verify that the implementations of management practices for nitrogen are as effective as possible?

10. Evaluate and make recommendations regarding the usage of various verification measurements of nitrogen control.

11. Evaluate the relative merits, and make recommendations regarding the usage of, surface water measurement systems derived from either receiving water

12. Evaluate and make recommendations on how best to integrate the results of the NitrogenTracking and Reporting System Task Force with any above recommendation regarding management practices and verification measures.

13. Evaluate and make recommendations on the reporting requirements to report budgeting and recording of nitrogen application on a management block basis versus reporting aggregated numbers on a nitrate loading risk unit level.

• Public mtg comments (5) • Work Sessions (4) • Written Comments

Aquifer Characteristics

The following points were repeatedly discussed with regard to the role of various models and groundwater monitoring data: [Q10] • Lag times between deep percolation of nitrates and the nitrates reaching the top of

the aquifer typically range from a year to up to extremes of several hundred years. • While there can always be exceptions, it cannot be assumed that groundwater

quality near the water table is reflective of management practices and the concentrations in deep percolating water, immediately above the groundwater monitoring point. Instead, many explanations and examples exist regarding the complex mixing of aquifer flows and the heterogeneous nature of the subsurface.

• Groundwater simulation model results are only approximate even on very large scales.

• California aquifer physical characteristics are very complex and even with large studies are poorly defined.

Monitoring first Encountered GW

• Very expensive • What does it tell us? • High N concentrations may indicate excellent

management. • What does it do to solve problem?

Changing Ag Landscape

Changing Ag Landscape

Considerations by panel

• Modeling root zone N dynamics • Monitor 1st encountered GW • Model GW to determine N Sources • Use of Proxy Measures

RECOMMENDED REGULATORY PROGRAM

1. Establishment of coalitions to serve as the intermediate body between farmers and the Regional Boards.

2. Adoption of the A/R ratio as the primary metric for evaluating progress on source control, with eventual impact on the groundwater quality. [Q9]

A/R =Nitrogen Applied/ (Nitrogen Removed via harvest) + (Nitrogen sequestered in the

permanent wood of perennial crops) 3. Development of a very strong, comprehensive, and sustained

educational and outreach program. Such a program will require different materials and presentation techniques for different audiences, such as individuals who may need certification, managers of irrigation/nutrient plans, irrigators, and farmers/managers. [Q8]

Recommended Regulatory Program 4. Creation and implementation of nitrogen/water management plans that

are truly plans rather than just a listing of best management practices. These must be customized by features such as crop and locale.

5. Reporting of key values (i.e., crop type, acreage, total nitrogen applied, and total nitrogen removed) by farms to the coalitions.

6. Trend monitoring of groundwater nitrate concentrations to track general aquifer conditions over multiple years.

7. Targeted research that will directly help the agricultural community to maintain and/or improve yields while simultaneously decreasing the A/R ratio on individual fields.

8. Use of multi-year reported values and monitored trends by the coalitions to inform the agricultural community of progress, to improve understanding of what is reasonable to attain and expect, and to sharpen improvement efforts.

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o AR-ratios not known for most crops, irrigation systems, conditions

o No vetted sampling protocols for most basic information (e.g., harvest removal)

o N-uptake vs. harvest removal o Historically, goal to maximize crop

yield and quality o Groundwater quality adds new

dimension

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o 100s of existing, vetted on-farm conservation practices

o More research unnecessary (i.e., detailed instrumentation of the root zone, groundwater monitoring, …)

Alternate Furrow Irrigation

Torpedos

Need to understand and remove barriers to adoption (where possible) o Education o Cap. cost, O&M, return on investment o Farm logistics o Land tenure o Social o Farm external (e.g., water district)

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On-farm reduction of N-mass emissions needs on-farm expertise and irrigation & nutrient management every day

Need customized Farm Irrigation and Nutrient Assessments …

o Individualized options for improvement o Qualified professionals o Achievable goals o Long-term collaboration with farmers o Boots on the ground

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Who will design and administer this program? o Curricula, target audiences o Venues, formats, frequencies o Materials, certification process o Standardization o Continuing education

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ILRP Approach Proposed New Path

• universal AR-ratio w/o consideration of current ratios for different crops/conditions, vetted data objectives, or sampling protocols

• recognizes critical role for education, awareness, and ultimate reduction of mass emissions to groundwater

• recognizes current limitations and need for program development prior to broad regulatory implementation

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ILRP Approach Proposed New Path

• emphasizes RWQCBs' ability to track management practices

• emphasizes on-farm development and implementation of custom irrigation and nutrient management plans

• recognizes complexity and promotes individualized solutions

• recognizes current lack of expertise

• provides higher level of accountability

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ILRP Approach Proposed New Path

• not included • emphasizes fundamental need for comprehensive education and certification program

• emphasizes positive involvement of the farming community while setting high standards

• sets clear expectations and consequences

• provides increased enforceability

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ILRP Approach Proposed New Path

• extensive field research and highly instrumented test sites

• recognizes limitations of assessment

• questions need for extensive field research

• uses the AR-ratio as the critical metric

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ILRP Approach Proposed New Path

• based on AR-ratio, management plans

• dependent on non-verifiable data and check-lists evaluated by non-agronomic staff that is remote from actual farm activities

• based on AR-ratio, review and assessment of actual MP implementation by competent professionals

• requires verifiable education, testing and certification tailored to different audiences

• stresses verifiability of key data (e.g., via externally documented fertilizer purchases)

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1) Partial nitrogen mass balance oProxy- or surrogate measurement for groundwater monitoring oRecognizes critical role of good water and nutrient management on

a field-scale to control deep percolation 2) Representative practice evaluation

o Investigate the relationship between partial N-mass balance and actual deep percolation/mass emissions to groundwater

oExtensive research (field trials, replicates, control groups) and data collection through detailed instrumentation of the vadose zone and groundwater monitoring

3) Long-term trend monitoring in regional well network oDelineate sub-regional and land use-specific differences oAssure compliance with broader groundwater quality objectives oRecognizes long time frames

ohttp://www.itrc.org/swrcb/panel.htm

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AR Ratio = 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴 𝑁𝑁𝐴𝐴𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝐴𝐴𝑁𝑁𝑅𝑅𝐴𝐴𝑅𝑅𝑁𝑁𝑅𝑅𝐴𝐴𝐴𝐴 𝑁𝑁𝐴𝐴𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝐴𝐴𝑁𝑁

Applied N = all sources including atmospheric deposition

Removed N = harvest + sequestered in the permanent wood of perennial crops This is a very partial mass balance o Focuses on a few key variables o Does not try to estimate the many chemical reactions,

mineralization rates, changes in storage o Does not calculate mass emissions below the root zone

Advantages of Approach and Recommendations

• Results from partial N balance approach provide some absolute, discrete values to work with (benchmarks)

• Measurements provide an indication of status of groundwater contamination

• Relative proportions of N pools can be portrayed at gross scale to improve understanding of N dynamics

• Provides methodical approach for estimating amount of N that should be applied