Identification and Control of Non-Point Sources of Microbial Pollution in a Coastal Watershed

EPA Grant Number: R828011
Title: Identification and Control of Non-Point Sources of Microbial Pollution in a Coastal Watershed
Investigators: Sanders, Brett , Horne, Alex , Keller, Robin , Sobsey, Mark D.
Current Investigators: Sanders, Brett , Grant, Stanley B. , Horne, Alex , Keller, Robin , Sobsey, Mark D.
Institution: University of California - Irvine , University of California - Berkeley , University of North Carolina at Chapel Hill
EPA Project Officer: Hiscock, Michael
Project Period: August 1, 2000 through July 31, 2003 (Extended to January 31, 2005)
Project Amount: $895,234
RFA: Water and Watersheds (1999) RFA Text |  Recipients Lists
Research Category: Water and Watersheds , Water


We propose (1) to characterize the spatiotemporal variability of microbial pollution in urban runoff and to identify the association between pathogens and indicator organisms, (2) to develop a novel strategy to control the impact of urban runoff on the microbial water quality of coastal wetlands and beaches during non-storm periods, and (3) to develop a multiple-objective decision model to aid stakeholders in selecting strategies to mitigate microbial pollution problems in coastal waters.


A well-defined and controllable system of flood control channels and a constructed marsh in Southern California will be utilized as the test site. The flood control infrastructure includes a network of pump stations with forebays that are engineered to lift runoff from below sea-level sub-basins and into tidally influenced flood control channels which drain to the sea. A sampling survey of forebay water and channel water will be undertaken to ascertain the spatiotemporal variability of pathogens (enteric viruses) and indicator microorganisms (Escherichia coli, enterococci, spores of Clostridium perfringens, fecal coliform, and male-specific and somatic bacteriophage) present in the watershed, with the goal of ascertaining the association between pathogen levels and indicator organisms both at the inlet to the open channel waterways, and at the outlet where runoff drains to the near-shore region. The control approach involves combining active and passive control strategies to mitigate the impact of urban runoff that is transported by flood control channels, through a constructed wetland, and into a recreational near-shore area. Pump station operation schedules that minimize the impact of urban runoff on coastal water quality will be determined, and the principal mechanisms responsible for pathogen removal by tidally influenced constructed wetlands will be identified through a series of microcosm studies. Stakeholders will be interviewed or surveyed to evaluate preferences towards various objectives associated with active and passive control strategies, and a decision making model will be developed to assess the efficacy of existing control alternatives and to identify previously unrecognized approaches for water quality control.

Expected Results:

Because flood control channels are a ubiquitous feature of urban watersheds and constructed wetlands have become an important resource for pollution mitigation, the primary data, control strategies, and stakeholder information obtained in this study could lead to regional and National strategies for reducing the adverse impact of urban runoff on coastal water quality.

Publications and Presentations:

Publications have been submitted on this project: View all 21 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 7 journal articles for this project

Supplemental Keywords:

urban runoff, non-point sources, coastal wetlands, flood control channels, active control, passive control, decision model., RFA, Scientific Discipline, Geographic Area, Water, Ground Water, Water & Watershed, Environmental Chemistry, State, Wet Weather Flows, Environmental Monitoring, Engineering, Watersheds, clostridium, pathogens, ecosystem modeling, fate and transport, coastal watershed, flood control, contaminant transport, suburban watersheds, bacteriophage, escherichia coli (e. coli), enterocci, man-made wetlands, urban runoff, decision making, runoff, pollution identification and control, recreational area, tidal influence, fecal coliform, decision model, microbial pollution, stormwater drainage, forebay water, non-point sources, water quality, California (CA), indicator organisms, stakeholders, active control, storm water, pump stations

Progress and Final Reports:

  • 2001 Progress Report
  • 2002
  • 2003
  • 2004
  • Final Report