Santa Margarita Region MS4 Permit – Pyrethroids Evaluation Jason E. Uhley, P.E. Riverside County Flood Control & Water Conservation District

 Santa Margarita Watershed Overview  Permit Requirements  Ongoing Activities Presentation Outline

Issued within RWQCB jurisdiction on Countywide Basis  Santa Ana Region – Santa Ana RWQCB  Santa Margarita Region – San Diego RWQCB  Whitewater River Region – Colorado RWQCB Introduction to NPDES MS4 Permits

General Watershed Information Total Area740 sq. mi. Riv. Co. Area540 sq. mi. Riv. Co. Population260,000 Watershed-Wide Non- Urban Land Use 93% Hydrologic ModificationYes Average Annual Rainfall10-12” in valleys Rainfall2.6” ImpairmentsNutrients, Metals, Turbidity Santa Margarita

Unique Conditions in the Santa Margarita Watershed  Ephemeral – Receiving waters typically dry  Limited rising groundwater near SMR  No connectivity with urban runoff during dry conditions Introduction to NPDES MS4 Permits

 Issued to municipal operators of MS4 (cities and County)  Regulates stormwater and non-stormwater discharges  Eliminate non-stormwater discharges  Manage stormwater discharges  Santa Margarita NPDES MS4 Permit (SD RWQCB)  County of Riverside  Cities of Temecula, Murrieta and now Wildomar  RCFC&WCD NPDES MS4 Basics

Permittee Structure RCFC&WCD Principal Permittee Murrieta Co-Permittee Temecula Co-Permittee County Co-Permittee

Typical Permit Compliance Programs Address:  Legal Authority  Elimination of Illegal Connections/Discharges  Construction Inspection  Business Inspection  Municipal Facility and Activity BMPs  New Development BMPs  Public Education and Outreach  Watershed Monitoring/Annual Reporting Introduction to NPDES MS4 Permits

 Permit Requires Monitoring at Major Receiving Waters  Chemistry  Bioassessment  Toxicity  If Toxicity detected, must conduct TIE  After TIE verifies source, Toxicity Reduction Evaluation required Basic Monitoring Program

Monitoring Locations

 – Persistent Toxicity detected in wet weather flows  – Pyrethroids determined as likely source  Initiated direct measurements for pyrethroids, TRE Notes: 1) Have not conducted sediment toxicity tests 2) Toxicity not detected during dry weather, however, receiving waters are limited to rising groundwater – no connectivity with urban runoff – during dry conditions Monitoring Results to Date

 Monitoring  TIEs to verify persistence  Pyrethroids testing to assist with source tracking  Regulatory  CDPR Labeling Requirements  CASQA Pesticides Sub-committee  Education and Outreach  HHW/ABOP  Coordinate with Ag Commissioner and UC Cooperative Extension  Require IPM for municipal operations  Point of Sale Outreach  General Education/Outreach Ongoing Activities

 Toxicity Reduction Evaluation  Continued evaluation of persistence and magnitude of toxicity  Literature Review  Source Evaluation and Tracking  Pyrethroids monitoring  Surveys of various representative land uses  Evaluate store sales, Ag. Commissioner, and CDPR data  Develop new BMPs  Public Outreach  Continued lobbying of CDPR, EPA Ongoing Activities

 Annualized Costs$135,525  Toxicity Testing - $20,700  TIE - $69,625  Pyrethroids Monitoring $14,000  TRE Cost - $31,200  BMP Implementation – To Be Determined Ongoing Activities