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RESEARCH FOR MANAGING URBAN WATERSHED MICROBIAL CONTAMINATION (PROJECT 1: MANAGING URBAN WATERSHED PATHOGEN CONTAMINATION: 2. EFFECT OF LAND USE AND SEASON ON MICROORGANISM CONCENTRATION ON URBAN STORMWATER RUNOFF; 3. MICROORGANISM DIE-OFF RATES UNDER VARIOUS CONDITIONS.
Citation:
Selvakumar*, A, M Borst*, R D. Arnone*, J. F. Walling, AND M K. Stinson*. RESEARCH FOR MANAGING URBAN WATERSHED MICROBIAL CONTAMINATION (PROJECT 1: MANAGING URBAN WATERSHED PATHOGEN CONTAMINATION: 2. EFFECT OF LAND USE AND SEASON ON MICROORGANISM CONCENTRATION ON URBAN STORMWATER RUNOFF; 3. MICROORGANISM DIE-OFF RATES UNDER VARIOUS CONDITIONS. Presented at WSWRD Peer Review, Cincinnati, OH, September 26 - 29, 2004.
Impact/Purpose:
To inform the public.
Description:
The Water Supply and Water Resources Division (WSWRD) developed a document entitled Managing Urban Watershed Pathogen Contamination (EPA 600/R-03/111). This document provides information to support specific steps of the total maximum daily load (TMDL) process for meeting water quality standards for microorganisms in urban watersheds. The final document is available through the internet at: www.epa.gov/ORD/NRMRL/pubs/index.html.
In the second project WSWRD investigated differences in pathogen and indicator organism concentrations in stormwater runoff between different urban land uses and seasons. The year-long study showed microorganism concentrations in runoff from high-density residentail areas are higher than those associated with low-density residential and landscaped commercial areas. Concentrations of microorganisms were affected by the season during which the samples were collected with the lowest concentrations observed during winter.
The third study estimated the die-off rate constants for identified organisms in stormwater and measured the influence of temperature, salinity, and light. These are the environmental parameters most often identified in the literature as affecting the decay rate constant. Results indicate that fecal coliform, E. coli, and enterocci persisted at higher levels at lower temperatures, the die-off rate constants increased with increasing temperatures. Decay rates do not vary with salinity. The experiments examining die-off due to sunlight are completed and the data reduction is in progress.