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

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

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

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?

TAC Review of Workplan Workplan must 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.

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

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

(Draft Revised)Monitoring Requirements Program Element Parameter Duration/ Time Frame Depth Sites Frequency Method   Resurfacing Groundwater Monitoring Discharge rates, and total and dissolved inorganic N and P Loading Into Estuary As needed N/A Former Stuart Mesa Agricultural Fields & Santa Margarita Valley Basin Biannual: Winter dry and summer dry monitoring Applicable Standard Methods Monitoring efforts include a QAPP and must be led by State Certified Geologist Estuary Monitoring Dissolved Oxygen (mg/l and percent saturation), temperature, pH, Salinity/conductivity, turbidity, water depth, and degree of tidal muting or influence April – October and during winter period (including 3 monitoring periods) Near surface ~ 0.5 meters 2 sites: I-5 bridge and Stuart Mesa bridge Continuous monitoring at 15 min. intervals Data sonde with optical sensor. In accordance with applicable SCCWRP Southern California Bight Regional Monitoring Protocols Estuary surface water chlorophyll a, total and dissolved inorganic N and P concentrations. April – October (monthly?) and 3 times during winter dry weather Applicable SWAMP and Standard Methods Macroalgal Biomass April – October Intertidal and or subtidal as appropriate within the three regions of Estuary - below I-5 bridge, above Stuart Mesa bridge until vegetation changes, and between the two bridges. Macroalgal biomass samples harvested representatively from each of three regions. Monthly Standard Operating Procedure (SOP) for Macroalgal Collection in Estuarine Environments. SCCWRP Technical Report #872 Estuary Monitoring (Cont.) Estuary Benthic Community Condition, Sediment %OC, sediment %N and %P, and sediment grain size. At depths that align with the Macroalgal sampling (so that relationships between Benthic Community Condition and other parameters may be logically inferred). Three randomly distributed sites for each of three regions in estuary. Once per year in the late summer Standard methods (Sediment Quality Assessment Technical Support Manual, SCCWRP Tech Report 582, 2009). Additional accepted methods that may be developed.

(Draft Revised)Monitoring Requirements Program Element Parameter Duration/ Time Frame Depth Sites Frequency Method   Santa Margarita River Monitoring River water flow, temperature, conductivity, ambient total and dissolved inorganic N and P. Monthly (May – October) and Bi-monthly (November – March)   N/A A minimum of one site for San Diego County, Riverside County, and USMC Base Camp Pendleton. Continuous flow Monthly May to October and Bi-monthly thereafter  (including November, January and March) Standard Operating Procedures for the collection of field data for bioassessments of California wadable streams: benthic macroinvertebrates, algae, and physical habitat (Bioassessment SOP). 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.

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?

Questions/Discussion

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.

SAG Workplan 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

Cost Estimate

Cost Estimate Task No. Description Year 1 Cost Year 2 Cost Year 3 Cost Year 4 Cost Total 1 Estuary Continuous Monitoring $74,185 $296,740 2 Estuary Surface Water Quality & Algal Biomass Monitoring $90,955 $363,820 3 Estuary Sediment Monitoring $45,653 $182,612 4 Santa Margarita River Monitoring $140,299 $123,496 $129,277 $516,568 5 Monitoring Plan and QAPP Preparation $36,372 $0 6 Annual Report Preparation $51,872 $65,962 $221,578 7 CEDEN Data $6,530 $26,120 8 Project Management & Meetings $15,480 $61,920 $461,346 $408,171 $428,042 $1,705,730

Total 4 Year Estimated Costs Cost Estimate Category Year 1 Cost Year 2 Cost Year 3 Cost Year 4 Cost Total 4 Year Estimated Costs Prepare Workplan and QAPP $36,372 $0 Field Work and Program Management Effort $259,887 $244,645 $250,165 $999,342 Laboratory Analysis, Materials, Supplies $105,385 $105,124 $106,685 $422,317 Report Preparation and CEDEN $58,402 $72,492 $247,698 Total $460,046 $408,171 $429,342 $1,705,730

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

Cost Allocation Factors Watershed area Population Land use Nutrient load

Questions/Discussion