Wastewater compounds in urban shallow groundwater wells correspond to exfiltration probabilities of nearby sewers

Abstract

Wastewater compounds are frequently detected in urban shallow groundwater. Sources include sewage or reclaimed wastewater, but origins are often unknown. In a prior study, wastewater compounds were quantified in waters sampled from shallow groundwater wells in a small coastal California city. Here, we resampled those wells and expanded sample analyses to include sewage- or reclaimed water-specific indicators, i.e. pharmaceutical and personal care product chemicals or disinfection byproducts. Also, we developed a geographic information system (GIS)-based model of sanitary sewer exfiltration probability--combining a published pipe failure model accounting for sewer pipe size, age, materials of construction, with interpolated depths to groundwater--to determine if sewer system attributes relate to wastewater compounds in urban shallow groundwater. Across the wells, groundwater samples contained varying wastewater compounds, including acesulfame, sucralose, bisphenol A, 4-tert-octylphenol, estrone and perfluorobutanesulfonic acid (PFBS). Fecal indicator bacterial concentrations and toxicological bioactivities were less than known benchmarks. However, the reclaimed water in this study was positive for all bioactivity tested. Excluding one well intruded by seawater, the similarity of groundwater to sewage, based on multiple indicators, increased with increasing sanitary sewer exfiltration probability (modeled from infrastructure within ca. 300 m of each well). In the absence of direct exfiltration or defect measurements, sewer exfiltration probabilities modeled from the collection system's physical data can indicate potential locations where urban shallow groundwater is contaminated by sewage.

An assessment of the replicability of a standard and modified sanitary risk protocol for groundwater sources in Greater Accra

“…Sanitary risk observation items for wells and boreholes were drawn from the exemplar protocols provided by the WHO (World Health Organization 1997 ). We then added observable contamination hazards potentially found in urban and peri-urban areas including: Presence of ‘flying toilets’, or defecation in polyethylene bags (Tumwebaze et al 2013 ), an excreta containment option for urban households lacking sanitation or diapers, also a growing waste management issue in low and middle income countries (Reese et al 2015 ) Locations of storm drains and blockages to storm drains, both associated with contamination of shallow urban groundwaters (Wakida and Lerner 2005 ; Kulabako et al 2007 ) Locations of sewerage pipes and leaky sewers (Wakida and Lerner 2005 ), associated with shallow urban groundwater contamination in the USA (Lee et al 2015 ) …”

“…Locations of sewerage pipes and leaky sewers (Wakida and Lerner 2005 ), associated with shallow urban groundwater contamination in the USA (Lee et al 2015 )…”

Biodegradation of the artificial sweetener acesulfame in biological wastewater treatment and sandfilters

“…After ingestion and absorption from the gut, ACE is largely excreted unchanged in urine without undergoing any metabolism ( Renwick, 1986 , von Rymon Lipinski and Hanger, 2001 ) and is therefore present in wastewater in notable concentrations. On a worldwide scale, concentrations in the range of 10–100 μg/L in wastewater treatment plant (WWTP) influents and effluents have been observed in more than 20 countries ( Arbeláez et al., 2015 , Buerge et al., 2009 , Gan et al., 2013 , Kokotou and Thomaidis, 2013 , Lee et al., 2015 , Ordonez et al., 2012 , Scheurer et al., 2009 , Tran et al., 2014b , Xu et al., 2016 ) with a maximum concentration of 2.5 mg/L ( Loos et al., 2013 ). As a consequence, ACE can be ubiquitously detected in anthropogenically influenced rivers and groundwater with concentrations up to the double-digit μg/L-range in surface waters, when these are highly impacted by wastewater discharge ( Voloshenko-Rossin et al., 2015 , Prasse et al., 2011 , Engelhardt et al., 2013 ).…”

Artificial Sweeteners Reveal Septic System Effluent in Rural Groundwater

“…Artificial sweeteners have been detected in rivers, lakes, and groundwater where wastewater is known to discharge (Brorström‐Lundén et al, 2008; Buerge et al, 2009; Scheurer et al, 2009; Oppenheimer et al, 2011; Spoelstra et al, 2013; Robertson et al, 2013; Van Stempvoort et al, 2013). They have also been found in the groundwater underlying urban areas with leaky sewer systems (Wolf et al, 2012; Tran et al, 2014; Lee et al, 2015) and as a component of landfill leachate (Roy et al, 2014; Clarke et al, 2015). …”