Timeline: 2007-2008
Client/Partner: AMEC
Study Location: Los Angeles River Watershed
Role: Lab Manager

Summary (Report Excerpt):

Recreational beneficial uses in the Los Angeles River (LA River) are impaired due to elevated concentrations of fecal coliform and E. coli. A Bacteria Total Maximum Daily Load (TMDL) for the LA River is being developed by the Los Angeles Region – Regional Water Quality Control Board (RWQCB) in cooperation with the Cleaner Rivers through Effective Stakeholder-led TMDLs (CREST) stakeholder group. In order to assist with dry weather source assessment and implementation of the TMDL, a Bacteria Source Identification (BSI) Study was developed and conducted through the CREST stakeholder process. The CREST stakeholder group involved in the Study included USEPA, RWQCB, City of Los Angeles and other watershed cities, LA County, Caltrans, Heal the Bay, Southern California Coastal Water Research Program (SCCWRP), the University of California, Davis, and others. The overall goal of the BSI Study was to increase the accuracy of the to-be-developed LA River Bacteria TMDL and improve the likelihood of success for future bacteria source control efforts associated with the TMDL’s implementation plan. That is, the study was designed to characterize the bacteria inputs to the LA River, support the development of a TMDL source assessment, and assist with prioritization of the types and locations of TMDL implementation actions. The BSI Study employed a microbial source tracking “toolkit” that assisted with identification of human versus non-human inputs including potentially-pathogenic human viruses. The dataset collected during the BSI Study is unprecedented within the LA River watershed in terms of the number and type of sampling locations, application of cutting-edge laboratory methods, and detail of gathered GIS information. In fact, the BSI Study is one of the most advanced microbial source tracking studies of urban runoff conducted to date.

Alexander Schriewer was the responsible contact person for sample processing, data analysis and reporting to create the source tracking and human pathogens database at the University of California, Davis.

Other companies and organizations involved:

  • Larry Walker and Associates
  • CH2MHill
  • CRG Marine Laboratories
  • CREST Stakeholders: USEPA, RWQCB, City of Los Angeles and other watershed cities, LA County, Caltrans, Heal the Bay, Southern California Coastal Water Research Program, the University of California, Davis and others

Report:

CREST (2008) Los Angeles River Bacteria Source Identification Study: Final Report, November 2008.