Model Stormwater Monitoring for Municipal
Separate Stormwater Systems in Southern California

This project describes a common design framework for municipal urban runoff programs and Regional Board staff to use in developing and/or revising program monitoring requirements for assessing receiving waters impacts, status and trends, toxicity, mass emissions, and source identification. The goal was to achieve a basic degree of comparability across southern California stormwater management agencies, while maintaining an individual programs ability to adapt to site-specific and local concerns.

The development of the model monitoring program was organized through the Southern California Stormwater Monitoring Coalition (SMC) and State Water Resources Control Board, which impaneled a technical committee including representatives from:

• Regional Water Quality Control Boards (Los Angeles, Santa Ana, San Diego)
• State Water Resources Control Board
• Municipal permittees (Counties of Ventura, Los Angeles, San Bernardino, Riverside, Orange, and San Diego)
• Heal the Bay
• Southern California Coastal Water Research Project (SCCWRP)

The technical guidance is presented in three documents:

• Monitoring Design Document - provides the approach, rationale, and methodology for developing the model monitoring program, which is structured around five fundamental management questions.
• Laboratory Manual - uses a performance-based quality assurance approach for setting accuracy, precision, and sensitivity goals for a common list of constituents.
• Information Management Manual - uses standardized data transfer formats for agencies to share information.

The technical committee provided many useful tools for agencies to implement the new designs at the local level including decision trees, adaptive monitoring triggers for increasing or decreasing effort, a ranking system for prioritizing toxicity identification efforts or bacterial source identification, and strategic incorporation of the model program based on existing monitoring effort. Two of the tools are available as stand alone products including:

• SDTF compliant database
• Power analysis tool for determining sampling frequency to detect trends (coming soon).