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Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations
Published on: September 11, 2016
Intra-storm variability in microbial partitioning and microbial loading rates
Leigh-Anne H Krometis1, Gregory W Characklis, Otto D Simmons
1Department of Environmental Sciences and Engineering, School of Public Health, Rosenau Hall-CB #7431, University of North Carolina, Chapel Hill, NC 27599-7431, USA. krometis@email.unc.edu
Water Research
|December 5, 2006
Summary
Microbial association with settleable particles in stormwater varies by organism type but remains consistent during storms. Early storm stages exhibit higher particle-associated microbial loading rates, significantly impacting water quality.
Area of Science:
- Environmental microbiology
- Water quality analysis
- Stormwater management
Background:
- Microbial transport in aquatic environments is heavily influenced by association with particulate matter.
- Understanding microbial partitioning to particles is crucial for assessing water contamination and ecological risk.
Purpose of the Study:
- To quantify the fraction of microbes associated with settleable particles in stormwater.
- To investigate how microbial partitioning behavior changes during storm events.
- To estimate microbial loading rates and cumulative loads during storms.
Main Methods:
- Analysis of stormwater samples collected during three distinct storm events at two sites.
- Utilized a calibrated centrifugation method to determine the percentage of microbes attached to settleable particles.
- Quantified five different indicator organisms, including fecal coliforms, Escherichia coli, enterococci, Clostridium perfringens spores, and total coliphage.
Main Results:
- Microbial partitioning to settleable particles varied by organism: Clostridium perfringens spores (approx. 65%), fecal coliforms, E. coli, enterococci (approx. 40%), and total coliphage (approx. 13%).
- Partitioning percentages remained relatively constant for each organism type throughout the storm events.
- Higher concentrations of settleable particles and microbes at the storm's onset resulted in elevated early-stage loading rates of particle-associated microbes.
Conclusions:
- Stormwater particle characteristics significantly influence microbial fate and transport, with distinct partitioning behaviors among different microbial groups.
- Early storm stages pose a higher risk for particle-associated microbial loading, necessitating consideration in stormwater infrastructure design.
- Single storm events can contribute microbial loads equivalent to months or years of dry-weather conditions, highlighting the substantial impact of storm events on water quality.
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