City Council
259 N. Wilma Avenue
Ripon, CA 95366
MEMO
To: Honorable City Council
From: James Pease, Public Works Director
Date: 10/08/2024
Subject: Nitrate Control Program
RECOMMENDED ACTION:
Authorize staff to proceed with joining the Local Management Zone (Pathway B) with other permittees to work together to reduce nitrate loading as required by the Central Valley Regional Water Quality Control Board, including signing the Valley Water Collaborative Contribution Agreement and paying the annual fee as required by the agreement.
BACKGROUND:
Increased agricultural, industrial, and municipal activities have resulted in dramatic increases in nitrate in groundwater throughout the Central Valley. Many residential well water users in the Central Valley rely on groundwater for drinking water, and some of them experience unsafe levels of nitrate. Nitrate is a tasteless, odorless, and invisible chemical that can cause health effects when found in high levels in drinking water. Nitrate is common in fertilizers and waste discharges in the Central Valley.
In May 2018, the Central Valley Regional Water Quality Control Board (CVRWQCB) adopted Resolution R5-2018-0034, approving new Salt and Nitrate Control Programs. The Nitrate Control Program (NCP) was developed to address nitrate accumulation issues in groundwater throughout the Central Valley Region. The goal of the Nitrate Control Program is to provide safe drinking water supplies, reduce nitrate impacts to water supplies and restore groundwater quality where reasonable and feasible.
The City of Ripon is subject to the Nitrate Control Program requirements for the City’s wastewater discharge from the City’s wastewater treatment plant to groundwater. The program covers the entire Central Valley Region and is broken into separate basins/sub-basins. Priority 1 Sub-basins began the program in 2021 and Priority 2 Sub-basins are required to begin the program in 2024. The City of Ripon is included in the Eastern San Joaquin Priority 2 Sub-basin Zone.
DISCUSSION/ANALYSIS:
In December of 2023 the City received the attached Notice to Comply letter from the CVRWQCB with a limited amount of time to select one of two pathways for compliance of the NCP.
The NCP Notice to Comply requires a choice between two compliance pathways:
Pathway A is an individual option that would require significant costly upgrades to the wastewater treatment plant in order to meet the nitrate standard.
Pathway B allows the City to join a Local Management Zone with other Permittees to work together to reduce nitrate loading and to provide replacement drinking water to communities and individuals whose wells are impacted by nitrates.
Staff reached out to our consultant Stantec who assists with the quarterly and annual reports for the City wastewater treatment plant to discuss the feasibility of Pathway A. It would require a large and highly complicated study to try and come up with findings that show how the City wastewater treatment plant does not contribute to the nitrate problem in the surrounding groundwater. Due to our wastewater treatment processes and the current nitrate levels in the groundwater surrounding the plant the most likely outcome would include significant upgrades to the plant and updating our existing discharge permit.
Staff recommends choosing Pathway B and approving the voluntary contribution agreement for participation in the Eastern San Joaquin Basin Management Zone administered by Valley Water Collaborative. Valley Water Collaborative is a collaborative management zone comprised of irrigated lands, dairies, wineries, industrial processors, and wastewater treatment plant permitted discharges. Pathway B allows more time for dischargers to reduce and eliminate nitrate contamination within the management zone.
The Valley Water Collaborative budget for 2024 is $220,220 which will fund the Preliminary Management Zone Proposal (PMZP) due on December 28, 2024. The PMZP will include identification of participating permitted dischargers, initial assessment of nitrate conditions in groundwater, potentially impacted public water supplies/domestic wells where nitrate exceeds water quality objectives, existing nitrate management practices of participating permitted dischargers, and an Early Action Plan (EAP) to ensure safe drinking water in the short-term while long-term solutions are developed and implemented as required by CVRWQCB.
Implementation of the EAP begins February 26, 2025, which will include an education aspect, free well testing, and free bottled water for those affected by nitrates above the accepted levels.
The Final Management Zone Proposal (FMZP) is due December 2025. The Valley Water Collaborative preliminary budget for 2025 is $397,668.
By December 2026, each priority sub-basin is required to submit a management zone implementation plan (MZIP) to the Regional Water Board. Early action plan implementation will continue until long-term drinking water solutions are implemented under the MZIP. The plan will first prioritize finding solutions for dischargers contributing the highest amount of nitrates into the groundwater within the management zone.
FISCAL IMPACT:
The Management Zone will be funded through the participating communities and industries who are required to comply with the NCP including municipalities, irrigated lands, dairies, wineries and industrial processors. The annual fees will vary based on the expenses necessary for plans and implementation, they are determined by type of industry and permitted flow. The 2024 annual fee for the City of Ripon is $2,500 which will be funded through the Sewer Enterprise Operating Fund. The Management Zone 2025 annual fee for the City of Ripon is estimated to be around $5,000. Moving forward into 2026 and beyond we anticipate slight increases in expenses as the implementation plan progresses.
Attachments:
1. Notice to Comply
2. Valley Water Collaborative Agreement