SMR Nutrient Initiative Group Investigative Order Workplan

1. SMR Nutrient Initiative Group Investigative Order Workplan Matt Yeager, D.Env Senior Flood Control Planner Riverside County Flood Control and Water Conservation District June 26, 2019

2. Tentative IO R9-2019-0007 • Purpose of the IO • …to assess the condition of the Estuary and to evaluate the linkage between nutrient loading trends resulting from implementation actions by…(the MS4 Permittees) • Estimated Costs $450K / year; for 4 yrs • More on costs in SAG meeting • Requires a Monitoring and Assessment Workplan • Monitoring and Assessment Workplan Questions • Monitoring Requirements • Estuary • SMR (River and Watershed) • Workplan Submittals

3. Tentative IO R9-2019-0007 • Compliance Dates • Workplan due within 6 months • Submit to SD Water Board by November 9 (11thMon) • Begin Monitoring within 60 days of Workplan approval • Regional Board review (30 days?) • 4 “water years” of monitoring (Oct 1 – Sep 30) • Start date = October 1, 2010? • 3 Annual Reports required starting January 31, 2021 • Final Report due March 31, 2024 • Monitoring and Assessment Workplan Questions

4. Monitoring and Assessment Workplan Questions • Is watershed mass loading of total nitrogen and total phosphorous to the River and Estuary reduced to levels that do not exceed the calculated assimilative capacity of the Estuary? • Do monitoring results confirm the assumption that the implementation and enforcement of existing NPDES permits and WDRs is sufficient to bring about the necessary nutrient load reductions to restore the Estuary in accordance with the schedule…? • Are the Estuary numeric targets in Finding 16 and the Draft Staff Report for macroalgal biomass, dissolved oxygen, and Benthic Community Condition being achieved and sustained? • If not, based on available information, what are the primary stressors causing unsatisfactory conditions?

5. TAC Review of Workplan • Workplanmust include: • Maps showing proposed monitoring locations and associated GIS data. • List of monitoring parameters. • Frequency of monitoring events. • Methods to be used to collect and analyze monitoring data. • A Quality Assurance Project Plan (QAPP) • An assessment of trends with projections for when the numeric targets would be achieved, or an explanation indicating why data is insufficient to do so.

6. TAC Review of Workplan • Workplan Development Schedule • Draft Workplan by August 15, 2019 • Review by TAC • Discuss at August 28 TAC meeting • Revised Draft Workplan by October 4 • Review by TAC as needed • Discuss at TAC meeting or by teleconference • Revise, finalize, and submit November 11 • QAPP will be prepared in Parallel • Clarify this requirement

7. TAC Review of Workplan • Any Recommendations/Direction from the TAC? • Monitoring requirements • Methods/Labs • Sampling Contractors • Review/Coordination

8. (Draft Revised)Monitoring Requirements

9. (Draft Revised)Monitoring Requirements Deleted Footnotes [1] Evaluate the use of depth, berm height, or other data as indicators of the condition at the mouth of the estuary (end member condition = fully open or fully closed). [2] Water quality parameters will be measured from November – April at intervals as determined during development of the Work Plan. [3] Sampling frequency will be evaluated following completion of one year of sampling; frequencies for subsequent years will be determined in coordination with the SMRNIG TAC and SAG. [4]Macroalgal sampling protocol will be developed by Camp Pendleton in coordination with the Regional Board and the SMRNIG TAC as part of the Work Plan.

10. Monitoring and Assessment Workplan Questions • Monitoring of resurfacing groundwater discharge rates and groundwater total nitrogen and total phosphorus mass loading into the Estuary, to confirm that resurfacing groundwater is no longer a significant source of nutrient loading to the Estuary. Camp Pendleton must monitor resurfacing groundwater nutrient loading into the Estuary from the former Stuart Mesa Agricultural Fields. Data from existing monitoring and modeling efforts may be used to estimate resurfacing groundwater nutrient loading into the Estuary from the Santa Margarita Valley Groundwater Basin. • What does this mean?

11. Questions/Discussion

12. SMRNIG Document Website--Intro • The Santa Margarita Watershed Nutrient Initiative – Stakeholder Group, composed of a broad range of stakeholders with diverse interests, was formed in 2012 to address nutrient issues in the Santa Margarita River Watershed. This Stakeholder Group, with support from a Technical Advisory Committee, is working through a collaborative, inclusive, and regional process, using state of the science techniques, to develop regulatory targets and monitoring programs, and to recommend management approaches to ensure that the biological, chemical, and physical integrity of the Santa Margarita River and its tributaries are protected.The Group currently is focused on the initial phase of this project, Phase 1, which targets the development of the methods that are used to prepare and implement a workplan to use a nutrient numeric endpoint (NNE) methodology to understand nutrient impacts to the SMR Lagoon. • Technical investigations were initiated in 2006 by the San Diego Lagoons Investigative Order (R9-2006-0076). Phases I and II of follow-up grant-funded technical work developed models to apply a nutrient numeric endpoint methodology to evaluate nutrient impacts to the SMR Lagoon, collected comparable data for nutrient loading and transport processes, and developed regulatory targets for the Lagoon. Through evaluation of the model simulations and discussions during the collaborative development of the targets, the stakeholders have achieved a greater understanding of the seasonal impact of nutrients on the beneficial uses. Phase I and II efforts were conducted from 2011 to 2018 and were supported by Proposition 84 IRWM grant funds. • In early 2019, the group initiated Phase III of the Project, which extends the work conducted for the Lagoon in Phases I and II to explore a range of biostimulatory targets that are protective of beneficial uses in the Santa Margarita River main stem under the present climate conditions and under climate change and/or extreme climate scenarios. Phase III will also identify potential restoration actions to improve biointegrity and reduce eutrophication, and will calculate load and waste load allocations required to meet the proposed biostimulatory targets. The technical work in Phase III is being funded by the San Diego Water Board.

13. SAGWorkplan Discussion • MS4s required to prepare/submit Workplan • Weston under contract to start Workplan • USMC Camp Pendleton working on GW monitoring • Schedule (submit November 11, 2019) • Who conducts the monitoring? TBD • Cost sharing for estuary monitoring? TBD • Expect to prepare an Agreement

14. Cost Estimate

15. Cost Estimate

16. Cost Estimate

17. Cost Estimate • Total = $1,839,828 (4 years) • River Monitoring = $516,168 • Estuary Monitoring = $843,172 • Continuous = $296,740 • Surface and algal = $363,820 • Sediment = $182,612 • GW Monitoring = $171,300 • Monitoring = $155,300 (4 yrs) • Model runs = $16,000 (2 runs; yrs 1 and 4) • Administration = $309,188 • Reporting = $247,898 • Proj Management = $61,290

18. Cost Allocation Factors • Watershed area • Population • Land use • Nutrient load

19. Questions/Discussion