Linking fecal bacteria in rivers to landscape, geochemical, and hydrologic factors and sources at the basin scale.
Proc Natl Acad Sci U S A
; 112(33): 10419-24, 2015 Aug 18.
Article
en En
| MEDLINE
| ID: mdl-26240328
ABSTRACT
Linking fecal indicator bacteria concentrations in large mixed-use watersheds back to diffuse human sources, such as septic systems, has met limited success. In this study, 64 rivers that drain 84% of Michigan's Lower Peninsula were sampled under baseflow conditions for Escherichia coli, Bacteroides thetaiotaomicron (a human source-tracking marker), landscape characteristics, and geochemical and hydrologic variables. E. coli and B. thetaiotaomicron were routinely detected in sampled rivers and an E. coli reference level was defined (1.4 log10 most probable numberâ
100 mL(-1)). Using classification and regression tree analysis and demographic estimates of wastewater treatments per watershed, septic systems seem to be the primary driver of fecal bacteria levels. In particular, watersheds with more than 1,621 septic systems exhibited significantly higher concentrations of B. thetaiotaomicron. This information is vital for evaluating water quality and health implications, determining the impacts of septic systems on watersheds, and improving management decisions for locating, constructing, and maintaining on-site wastewater treatment systems.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Microbiología del Agua
/
Contaminantes del Agua
/
Agua
/
Heces
Tipo de estudio:
Prognostic_studies
País/Región como asunto:
America do norte
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
2015
Tipo del documento:
Article