Nutrients

Nutrients in the San Francisco Bay are a major issue for the Bay Area water quality community.  Historically, the San Francisco Bay has not been adversely impacted by nutrient loading even though it is nutrient-enriched compared to other estuaries around the country. Stakeholders in the Region wish to better understand this resiliency, and whether it may be threatened in the future. Numerous scientific studies are being conducted by several entities, including the Regional Monitoring Program, to understand the impact of nutrients on the San Francisco Bay.  BACWA members are major contributors to help fund the studies.  While these studies are ongoing, BACWA leadership is working with regulators to ensure that future nutrient effluent limits are based on sound science.

This page provides a central location to access BACWA’s library of documents related to nutrients, links to nutrient efforts around the Bay Area, as well as nutrient-related presentations from previous meetings.

3rd Nutrient Watershed Permit

The third Nutrient Watershed Permit was adopted on July 10,  2024 and requires reduction in nutrient loading to the in the San Francisco Bay. Resources related to the 3rd Nutrient Watershed Permit are listed below:

• BACWA Press Release on Nutrient Watershed Permit (July 2024)
• Handout on Nutrient Watershed Permit (March 2024)
• Nutrient Infographic (March 2024)
• Regional Water Board Memo on Numeric Translation of Narrative Objective (April 2024)
• BACWA Comments on Nutrient Removal Timelines (Jan 2024)
• Nutrient Fact Sheet (Jan 2023)

2nd Nutrient Watershed Permit – 2019

The second Nutrient Watershed Permit was adopted on May 8, 2019, and went into effect on July 1, 2019.  The permit has four central tenets:

1. Nutrient Monitoring– Each agency is responsible for its own effluent monitoring, as required by the Permit. Some monitoring parameters changed from the first Nutrient Watershed Permit:

• New influent monitoring requirements for agencies rated >10 mgd
• Effluent monitoring of TKN and soluble reactive phosphorus monitoring no longer required
• Reporting year now lines up with water year (October 1 to September 30), whereas previously it was permit year (July 1 to June 30)

2. Reporting – BACWA will continue to provide the group annual report, due each year on February 1.  Agencies will input their data into  the Group Annual Report Data Input Workbook, updated for the monitoring parameters in the 2nd Watershed Permit and provided to agencies.

3. Support for Scientific Studies – In compliance with the Permit, BACWA is funding scientific studies associated with the San Francisco Bay Nutrient Management Strategy. The governance structure for the studies is illustrated by the following graphic:

Other ongoing Regional Scientific Efforts that are included in the orange box include the Regional Monitoring Program (RMP) Nutrient Strategy, Surface Water Ambient Monitoring Program (SWAMP) Suisun Bay Workplan, and the San Francisco Bay Nutrient Numeric Endpoints (NNE) Development which is part of the Statewide initiative to address nutrients. The level of support for the science increased from $880K/yr in 1st Watershed Permit, to $2.2M/yr in 2nd Watershed Permit

4. Special Studies – Two new studies were required in the Watershed Permit:

• Regional Evaluation of Potential Nutrient Discharge Reduction by Natural Systems
• Regional Evaluation of Potential Nutrient Discharge Reduction by Water Recycling

These 2nd Nutrient Watershed Permit studies were completed in June 2023 and are available here.

All permit compliance activities, other than individual monitoring, to be funded by BACWA through the Nutrient Surcharge.

In addition to the above requirements, the 2nd Nutrient Watershed Permit Fact Sheet established a baseline against which early actions can be measured. The baseline for each agency is its maximum dry season average of total inorganic nitrogen from the period 2014-2017. The Fact Sheet includes “Load Targets”, which reflect loads 15% higher than the baseline, and which agencies are expected to be able to meet in 2024. Depending on the results of the Science Program, the Regional Water Board may establish load caps in the 2024 permit. If the loads caps are based on the Load Targets, the Regional Water Board may adjust them if necessary to account for decreased recycled water demand, increased biosolids management, increased daytime worker population, or new or expanded waste-to-energy programs. The Fact Sheet also identifies “Early Actors”, which are agencies committed to taking action to reduce nutrients by 2024. These agencies will likely not be required to further reduce nutrients prior to actions taken by other agencies in their subembayment.

 1st Nutrient Watershed Permit – 2014

The first  Nutrients Watershed Permit required identification of treatment optimization and upgrade opportunities for all major dischargers – BACWA worked with a consultant team led by HDR to perform the Regional Optimization and Upgrade Studies that were required by the watershed permit. The consultant team conducted site visits throughout Spring and Summer of 2015 to identify optimization, upgrade and sidestream treatment alternatives for all the facilities that were required to participated in the Studies. Individual Facility Reports were included in the final Optimization/Upgrade Report as appendices, and were summarized in the main body of the Report. The Final Nutrient Treatment by Optimization and Upgrade Study report was submitted to the Regional Water Board on June 26 ,2018.