Effects of Climate and Sewer Condition on Virus Transport to Groundwater

Abstract

Pathogen contamination from leaky sanitary sewers poses a threat to groundwater quality in urban areas, yet the spatial and temporal dimensions of this contamination are not well understood. In this study, 16 monitoring wells and six municipal wells were repeatedly sampled for human enteric viruses. Viruses were detected infrequently, in 17 of 455 samples, compared to previous sampling at these wells. Thirteen of the 22 wells sampled were virus-positive at least once. While the highest virus concentrations occurred in shallower wells, shallow and deep wells were virus-positive at similar rates. Virus presence in groundwater was temporally coincident, with 16 of 17 virus-positive samples collected in a six-month period. Detections were associated with precipitation and occurred infrequently during a prolonged drought. The study purposely included sites with sewers of differing age and material. The rates of virus detections in groundwater were similar at all study sites during this study. However, a relationship between sewer age and virus detections emerged when compared to data from an earlier study, conducted during high precipitation conditions. Taken together, these data indicate that sewer condition and climate affect urban groundwater contamination by human enteric viruses.

Drinking water quality from rural handpump-boreholes in Africa

“…The reasons for this are uncertain, but could be linked to more intense rainfall and/or flooding under wetter conditions (Bridgman et al 1995, Wu et al 2016 and the activation of rapid recharge pathways and/or shallower groundwater tables under wetter climate conditions (Gotkowitz et al 2016, Cuthbert et al 2019. It has been previously suggested that under wetter climatic conditions, microbiological contamination may be higher (Gotkowitz et al 2016), and with higher contamination during the wet season (e.g. Sorensen et al 2015aSorensen et al , 2015b.…”

High levels of sewage contamination released from urban areas after storm events: A quantitative survey with sewage specific bacterial indicators

“…This leaking sewage can infiltrate drinking water distribution pipes under conditions of low water pressure or when there is a water main break [ 61 ]. Sewage can also contaminate groundwater that is used as a drinking water source, which is of high concern [ 18 , 19 , 59 , 62 ], particularly if it is untreated [ 63 ]. Drinking water systems, along with wastewater and sewer conveyance infrastructure, are ranked as a D− and D, respectively, by the American Association of Civil Engineers [ 64 ], and can be expected to deteriorate further over time without significant investments.…”

“…Human fecal contamination, i.e., untreated sewage, has the highest potential to cause disease because humans are the reservoirs for many human pathogens [ 17 ], although agricultural runoff can also carry zoonotic pathogens [ 10 ]. In urban areas, untreated sewage released from failing sewer infrastructure can leach into soil and migrate into groundwater [ 18 , 19 ] and into drinking water distribution systems under conditions of reduced pressure [ 20 ]. Stormwater systems have been found to be frequently contaminated by sanitary sewage as a result of infiltration of leaking sewage or illicit cross-connections, resulting in untreated sewage discharging directly into rivers and streams [ 21 , 22 ].…”

Présence de virus humains et indicateur microbien dans les systèmes aquifères utilisés pour l’alimentation en eau potable: méta-analyze de 12 études internationales

“…It constitutes about 95% of the world’s accessible freshwater (Chilton and Seiler 2006 ; Howard et al 2006 ; McKay 2011 ) and is often used with little or no treatment (Pedley et al 2006 ). Contamination of groundwater with human enteric viruses is a global issue (Blaschke et al 2016 ; Gotkowitz et al 2016 ; Hynds et al 2014 ; USEPA 2006a , b ), as consumption of contaminated water can result in elevated rates of endemic illness and waterborne disease outbreaks in affected communities (Beer et al 2015 ; Borchardt et al 2011 ; Cho et al 2014 ; Guzman-Herrador et al 2015 ; Hilborn et al 2013 ; Jack et al 2013 ; Wallender et al 2014 ; Zhou et al 2012 ). Enteric viruses implicated in waterborne outbreaks include enteroviruses, hepatitis A, rotavirus, and norovirus (Craun et al 2010 ; Hejkal et al 1982 ), but others such as adenoviruses, Aichi virus 1, hepatitis E, and reoviruses, potentially are capable of groundwater-borne transmission.…”

“…Viral and other pathogens and microbial indicators enter aquifers through multiple sources and pathways, including leachates from sanitary landfills, on-site septic waste treatment discharges, broken sewage lines, runoff from urban, agricultural and natural areas, and water reuse by direct injection of inadequately treated wastewater into aquifers (Borchardt et al 2012 ; Costan-Longares et al 2008 ; Gotkowitz et al 2016 ). Fecal contamination from the surface may also get into groundwater through improperly constructed, protected, or maintained wells (Hynds et al 2014 ).…”