title: Source tracking swine fecal waste in surface water proximal to swine concentrated animal feeding operations.
abstract: Swine farming has gone through many changes in the last few decades, resulting in operations with a high animal density known as confined animal feeding operations (CAFOs). These operations produce a large quantity of fecal waste whose environmental impacts are not well understood. The purpose of this study was to investigate microbial water quality in surface waters proximal to swine CAFOs including microbial source tracking of fecal microbes specific to swine. For one year, surface water samples at up- and downstream sites proximal to swine CAFO lagoon waste land application sites were tested for fecal indicator bacteria (fecal coliforms, Escherichia coli and Enterococcus) and candidate swine-specific microbial source-tracking (MST) markers (Bacteroidales Pig-1-Bac, Pig-2-Bac, and Pig-Bac-2, and methanogen P23-2). Testing of 187 samples showed high fecal indicator bacteria concentrations at both up- and downstream sites. Overall, 40%, 23%, and 61% of samples exceeded state and federal recreational water quality guidelines for fecal coliforms, E. coli, and Enterococcus, respectively. Pig-1-Bac and Pig-2-Bac showed the highest specificity to swine fecal wastes and were 2.47 (95% confidence interval [CI]=1.03, 5.94) and 2.30 times (95% CI=0.90, 5.88) as prevalent proximal down- than proximal upstream of swine CAFOs, respectively. Pig-1-Bac and Pig-2-Bac were also 2.87 (95% CI=1.21, 6.80) and 3.36 (95% CI=1.34, 8.41) times as prevalent when 48 hour antecedent rainfall was greater than versus less than the mean, respectively. Results suggest diffuse and overall poor sanitary quality of surface waters where swine CAFO density is high. Pig-1-Bac and Pig-2-Bac are useful for tracking off-site conveyance of swine fecal wastes into surface waters proximal to and downstream of swine CAFOs and during rain events.
authors.affiliation: Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA; Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA. Electronic address: cheaney1@jhu.edu.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Heaney
authors.affiliation: Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Myers
authors.affiliation: Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Steve
authors.initials: S
authors.lastname: Wing
authors.affiliation: Rural Empowerment Association for Community Help (REACH), Warsaw, NC, USA.
authors.forename: Devon
authors.initials: D
authors.lastname: Hall
authors.affiliation: Rural Empowerment Association for Community Help (REACH), Warsaw, NC, USA.
authors.forename: Dothula
authors.initials: D
authors.lastname: Baron
authors.affiliation: Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Jill R
authors.initials: JR
authors.lastname: Stewart
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D041963:Bacteroidetes; D016983:Enterococcus; D004784:Environmental Monitoring / Q000379:methods*; D004926:Escherichia coli; D005243:Feces; D012722:Sewage / Q000032:analysis*; D013552:Swine; D014871:Water Microbiology; D014876:Water Pollution / Q000032:analysis* / Q000706:statistics & numerical data
chemical_list: D012722:Sewage
keywords: Concentrated animal feeding operation; E. coli; Enterococcus; Fecal pollution; Microbial source tracking; Run-off; Swine; Water quality