Keywords

Integrated Environmental Modeling; Watershed modeling; QMRA; Pathogens; FIB

Location

Session H1: Environmental Modeling, Software, and Data to Support Quantitative Microbial Risk Assessments (QMRAs)

Start Date

16-6-2014 10:40 AM

End Date

16-6-2014 12:00 PM

Abstract

We evaluated the potential for human illness from a hypothetical recreational exposure to freshwater that was impacted by land-applied, agricultural animal fecal material. The scenario included 1) fresh cattle manure, pig slurry, or chicken litter (fecal material) land-applied, adjacent to a freshwater waterbody at standard agronomic rates (based on nutrient management); 2) fecal materials containing fecal indicator bacteria (FIB) and pathogens of public health concern (reference pathogens) at levels reported in peer-reviewed literature; 3) FIB and reference pathogens mobilized via runoff at rates estimated from our rainfall simulation experiments; 4) primary recreational contact (e.g., swimming) occurring in undiluted runoff at the edge of the waterbody or in diluted runoff containing specific reference levels of FIB in the waterbody; and 5) exposure to reference pathogens occurring through ingestion of water during recreation. We present quantitative microbial risk assessment (QMRA) model results based on this exposure scenario. We also compare results to our previously published work addressing direct contamination to freshwater. Finally, we discuss management considerations and implications for site-specific water quality criteria.

 
Jun 16th, 10:40 AM Jun 16th, 12:00 PM

Quantitative Microbial Risk Assessment of Freshwater Impacted by Animal Fecal Material

Session H1: Environmental Modeling, Software, and Data to Support Quantitative Microbial Risk Assessments (QMRAs)

We evaluated the potential for human illness from a hypothetical recreational exposure to freshwater that was impacted by land-applied, agricultural animal fecal material. The scenario included 1) fresh cattle manure, pig slurry, or chicken litter (fecal material) land-applied, adjacent to a freshwater waterbody at standard agronomic rates (based on nutrient management); 2) fecal materials containing fecal indicator bacteria (FIB) and pathogens of public health concern (reference pathogens) at levels reported in peer-reviewed literature; 3) FIB and reference pathogens mobilized via runoff at rates estimated from our rainfall simulation experiments; 4) primary recreational contact (e.g., swimming) occurring in undiluted runoff at the edge of the waterbody or in diluted runoff containing specific reference levels of FIB in the waterbody; and 5) exposure to reference pathogens occurring through ingestion of water during recreation. We present quantitative microbial risk assessment (QMRA) model results based on this exposure scenario. We also compare results to our previously published work addressing direct contamination to freshwater. Finally, we discuss management considerations and implications for site-specific water quality criteria.