1. Summary

The goal of the project is to design the most efficient forensic and real-time monitoring and evaluation program for the Russian River watershed to identify: 1) potential primary sources of potentially pathogenic fecal bacteria (e.g., dairies, municipal waste/runoff, recreational sites), 2) potential secondary sources (e.g., benthic sediments, periphyton, side channels, stock ponds), and 3) contributing factors (e.g., agricultural fertilizer, managed flows, water temperature, available organic material). The proposed evaluation program will resolve spatio-temporal issues, problems with source identification, potential load allocations, and factors that contribute to in-stream exacerbation or remediation of the problem. The program will be designed to support TMDL planning and implementation.

Identification of pathogen sources, transport mechanisms and pathways, and storage sites in a complex watershed requires concurrent scientific assessment of many physical, chemical, and biological characteristics of the watershed. Currently in the Russian River watershed there is incomplete understanding of the actual sources of potentially-pathogenic fecal organisms and pathways for exposure of local populations. The scientific literature provides some coverage of the relevant issues in the Russian River watershed. Critical research issues in the technical and scientific literature include: 1) identifying major source areas and types of fecal matter sources during different seasons, 2) transport mechanisms and processes in surface and sub-surface waters, 3) extent of contribution and locations of bacterial hold-over and storage from winter storm runoff to summer loads, 4) identification of vertebrate host species for pathogenic organisms in various places and times, 5) relationship between environmental factors and measured bacterial concentrations, 6) use and identification of appropriate indicator fecal bacteria species and strains, and 7) whether a testable model (conceptual and physical) can be created that explains bacterial conditions.

There are 3 main areas of investigation that should be pursued in the pre-TMDL investigation: 1) spatio-temporal localization of sources and hold-over bacterial reservoirs throughout the watershed; 2) appropriate identification techniques for index organisms (including identification method and host-strain relationships); and 3) adequate monitoring program for monitoring TMDL implementation effectiveness (including sampling frequencies, locations, and index organisms). These investigations can be feasibly pursued for a normal water-year with a bacteria monitoring program that includes a subsequent data analysis and interpretation phase.