Grantee Research Project Results
Dynamics of Point and Non-Point Source Fecal Pollution from an Urban Watershed in Southern CaliforniaEPA Grant Number: F5A10035
Title: Dynamics of Point and Non-Point Source Fecal Pollution from an Urban Watershed in Southern California
Investigators: Surbeck, Cristiane Q.
Institution: University of California - Irvine
EPA Project Officer: Hahn, Intaek
Project Period: September 1, 2005 through September 1, 2008
Project Amount: $98,804
RFA: STAR Graduate Fellowships (2005) RFA Text | Recipients Lists
Research Category: Academic Fellowships
Urban runoff has been recognized as a major source of pollutants to sensitive receiving waters. This project is motivated by the observation that storm water discharged from the Santa Ana River affects coastal water quality at economically important beaches along the Pacific Ocean in southern California. The occurrence of this pollution is complex because it happens in an urban watershed, where the movement of surface water is influenced by a complex network of flood-control, water reclamation, and wastewater treatment infrastructure. In this project, we study suspended particles and fecal indicators from point and non-point sources of pollution in the Santa Ana River and tributaries.
The objective of this project is to study the occurrence patterns and transport behavior of suspended particles and fecal indicators in the Santa Ana River watershed in southern California in order to better understand how to control and treat pollution into receiving waters. Results of this project will be shared with local county authorities to facilitate the establishment of water quality standards, or TMDLs (total maximum daily loads).
Field data will be collected during dry and wet weather from different sites in the Santa Ana River watershed and include stream discharge, rainfall, suspended particle size spectra, suspended solids, fecal indicator bacteria, fecal indicator viruses, and human viral pathogens. The data collected will undergo statistical analysis and will be interpreted based on existing knowledge of microbiology and sediment transport theory.
Some expected results are the following:
- We will verify whether fecal indicator loadings scale as a power-law with stream discharge. This has been established at two sites within this project and will likely be confirmed at other sites in the near future. This scaling signifies that fecal indicator concentrations can be estimated if the stream discharge is known.
- We will provide a framework for determining whether particles in storm water runoff within rivers originate from bed erosion, bank erosion, or a combination of both.
- We will assess whether wastewater treatment plant disinfection processes are killing fecal indicator bacteria before discharging treated effluent or if these bacteria are only temporarily inactivated and will re-grow once reintroduced into a river system.