As an outgrowth of the Nitrogen/TDS Task Force, the agencies responsible for implementing the Basin Plan Amendments formed the Basin Monitoring Task Force, and SAWPA was identified to administer/facilitate that effort.

As follow up to the Nitrogen TDS Task Force efforts, a new Task Force was formed in August 2004 consisting of 17 water and wastewater agencies in the Santa Ana Watershed to compile and collect monitoring data to evaluate the water quality of the Santa Ana River on an annual basis, and the groundwater basins throughout the watershed every three years. The 17 agencies responsible for completing these tasks and the actual tasks were included in the RWQCB Basin Plan as a result of the January 2004 Nitrogen and TDS Basin Plan Amendment.
Regulatory Links
RWQCB

The Task Force is administered by SAWPA and meets monthly. The primary work tasks include the following:
Preparation of an annual water quality report for the Santa Ana River Reaches 2, 4 & 5 necessary to assure compliance with both surface water objectives of the defined river reaches and the underlying groundwater objectives.
Preparation of a watershed-wide TDS/Nitrogen ambient water quality update every three years to determine the current ambient groundwater quality in the watershed for TDS/Nitrogen.
The completion of a watershed-wide TDS/Nitrogen groundwater monitoring program and annual SAR report is intended to assess current water quality, to determine whether TDS/Nitrate-Nitrogen water quality objectives for management zones are being met or exceeded, and to update assimilative capacity findings.
Stakeholders
- City of Riverside
- Colton/San Bernardino Regional Tertiary Treatment and Water Reclamation Authority
- Eastern Municipal Water District
- Elsinore Valley Municipal Water District
- Inland Empire Utilities Agency
- Irvine Ranch Water District
Taskforce Agenda Packets and Meeting Notes
Santa Ana River Water Quality Reports
These reports fulfill the requirement to prepare an Annual Report of Santa Ana River Water Quality pursuant to the 2004 Basin Plan Amendment. Contained within these reports are water quality data required to implement the surface water monitoring program necessary to determine compliance with the nitrogen and TDS objectives of the SAR and, thereby, the effectiveness of the wasteload allocations.
2021 Report | Appendix B: Water Quality and Flow Data
2020 Report | Appendix B: Water Quality and Flow Data
2019 Report | Appendix B: Water Quality and Flow Data
Recomputation of Ambient Water Quality (AWQ) Reports
As part of the agreement to adopt the 2004 Basin Plan amendment, the affected parties have agreed to recompute ambient water quality for individual management zones every three years. The determination of current ambient quality shall be accomplished using methodology consistent with that employed by the TIN/TDS Taskforce (20-year running averages) to develop the TDS and nitrate water quality objectives included in the 2004 Basin Plan.
Santa Ana River Wasteload Allocation Model (WLAM) Reports
Wasteload allocations for regulating discharges of TDS and total inorganic nitrogen (TIN) to the Santa Ana River, and thence to groundwater management zones recharged by the River, are an important component of salt management for the Santa Ana Basin.
- 2019 Santa Ana River Wasteload Allocation Model Summary Report
- Summary Report Part 1 of 3: Text
- Summary Report Part 2 of 3: Figures and Tables
- Summary Report Part 3 of 3: Appendices
- Appendix B Data
- Supplemental Report
- Addendum to the 2008 Santa Ana River Wasteload Allocation – Model Report: Scenario 7 (July 2010)
- Addendum to the 2008 Santa Ana River Wasteload Allocation – Model Report: Scenario 8 (January 2015)
Miscellaneous
- Quantification of Nitrogen Removal Under Recycled Water Ponds
- Nitrogen Losses from Recycled Water Systems
- Volume-Weighted TDS Concentration of POTW Discharge above Prado Dam during August-September memo, June 2015, WEI Inc.
- 2010 Preliminary Assessment of Assimilative Capacity for TDS and Nitrogen in the San Timoteo Management Zone, Wildermuth Environmental Inc.
For further information about this project, please contact Mark Norton
Email: First name initial last name @sawpa.org | Example: jsmith@sawpa.org