Santa Margarita Region MS4 Permit – Pyrethroids Evaluation
Jason E. Uhley, P.E.Jason E. Uhley, P.E.Riverside County Flood Control & Water Riverside County Flood Control & Water
Conservation DistrictConservation 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 Area 740 sq. mi.
Riv. Co. Area 540 sq. mi.
Riv. Co. Population 260,000
Watershed-Wide Non-Urban Land Use
93%
Hydrologic Modification Yes
Average Annual Rainfall 10-12” in valleys
2006-2007 Rainfall 2.6”
Impairments Nutrients, 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 StructureRCFC&WCD
Principal Permittee
MurrietaCo-Permittee
TemeculaCo-Permittee
CountyCo-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
2005-2006 – Persistent Toxicity detected in wet weather flows
2006-2007 – Pyrethroids determined as likely source
2007-2008 - 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