TY - JOUR
T1 - Modeling riverine pathogen fate and transport in Mexican rural communities and associated public health implications
AU - Robles-Morua, Agustin
AU - Mayer, Alex S.
AU - Auer, Martin T.
AU - Vivoni, Enrique
N1 - Funding Information:
We gratefully acknowledge the support of the Mexican federal government of the first author through a CONACYT PhD fellowship. The assistance of Mr. Ryan Biehl while a MS student in the field aspects of this work is acknowledged. Mr. Biehl was supported by an NSF S-STEM fellowship ( NSF award DUE-0806569 ). The assistance of Ms. Cara Shonsey in conducting the QUAL2K simulations is acknowledged as well.
PY - 2012/12/30
Y1 - 2012/12/30
N2 - The discharge of untreated or poorly treated wastewater to river systems remains a major problem affecting public and environmental health, particularly in rural communities of less developed countries. One of the primary goals in setting policies for wastewater management is to reduce risks to human health associated with microbial contamination of receiving water. In this study, we apply a surface water quality model to develop an Escherichia coli based indicator that reflects the quality of surface water and the potential impact to recreational users in a large, rural river in northwest Mexico (upper Sonora River). The model assesses the relative importance of streamflow variations and the uncertainty in E. coli removal coefficient parameters for the predictions of E. coli concentrations in the river. Given the sparse information on streamflow, we use a physically-based, distributed hydrologic model to generate tributary contributions to the river. We determined the best estimate and uncertainty of E. coli removal rates to explore the impacts of parameter uncertainty on the transport of E. coli downstream from two wastewater discharge zones. Our results depict the regions in the river that are in noncompliance with fresh water pathogen norms. The impact of streamflow variability and uncertainty in the removal rates of pathogen indicators was used to derive a range of river distances in noncompliance. The comparison between two sites with different streamflow behaviors was used to illustrate the impacts of streamflow spatiotemporal variability on pathogen indicators. We derive a simple relationship that can be used to assess the relative importance of dilution (ratio of wastewater discharge to river discharge) and pathogen removal (ratio of residence time to reaction time).
AB - The discharge of untreated or poorly treated wastewater to river systems remains a major problem affecting public and environmental health, particularly in rural communities of less developed countries. One of the primary goals in setting policies for wastewater management is to reduce risks to human health associated with microbial contamination of receiving water. In this study, we apply a surface water quality model to develop an Escherichia coli based indicator that reflects the quality of surface water and the potential impact to recreational users in a large, rural river in northwest Mexico (upper Sonora River). The model assesses the relative importance of streamflow variations and the uncertainty in E. coli removal coefficient parameters for the predictions of E. coli concentrations in the river. Given the sparse information on streamflow, we use a physically-based, distributed hydrologic model to generate tributary contributions to the river. We determined the best estimate and uncertainty of E. coli removal rates to explore the impacts of parameter uncertainty on the transport of E. coli downstream from two wastewater discharge zones. Our results depict the regions in the river that are in noncompliance with fresh water pathogen norms. The impact of streamflow variability and uncertainty in the removal rates of pathogen indicators was used to derive a range of river distances in noncompliance. The comparison between two sites with different streamflow behaviors was used to illustrate the impacts of streamflow spatiotemporal variability on pathogen indicators. We derive a simple relationship that can be used to assess the relative importance of dilution (ratio of wastewater discharge to river discharge) and pathogen removal (ratio of residence time to reaction time).
KW - Pathogen fate and transport
KW - Wastewater contamination
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U2 - 10.1016/j.jenvman.2012.08.035
DO - 10.1016/j.jenvman.2012.08.035
M3 - Article
C2 - 22996002
AN - SCOPUS:84864743293
SN - 0301-4797
VL - 113
SP - 61
EP - 70
JO - Journal of Environmental Management
JF - Journal of Environmental Management
ER -