Assessment of virus removal by managed aquifer recharge at three full-scale operations

Abstract

Managed aquifer recharge (MAR) systems such as riverbank filtration and soil-aquifer treatment all involve the use of natural subsurface systems to improve the quality of recharged water (i.e. surface water, stormwater, reclaimed water) before reuse. During MAR, water is either infiltrated via basins, subsurface injected or abstracted from wells adjacent to rivers. The goal of this study was to assess the removal of selected enteric viruses and a potential surrogate for virus removal at three full-scale MAR systems located in different regions of the United States (Arizona, Colorado, and California). Samples of source water (i.e., river water receiving treated wastewater and reclaimed water) before recharge and recovered groundwater at all three sites were tested for adenoviruses, enteroviruses, Aichi viruses and pepper mild mottle virus (PMMoV) by quantitative polymerase chain reaction (qPCR). Samples of groundwater positive for any virus were also tested for the presence of infectious virus by cell culture. PMMoV was the most commonly detected virus in the groundwater samples. Infectious enteric viruses (reovirus) were only detected in one groundwater sample with a subsurface residence time of 5 days. The results suggested that in groundwater with a residence time of greater than 14 days all of the viruses are removed below detection indicating a 1 to greater than 5 log removal depending upon the type of virus. Given its behavior, PMMoV may be suitable to serve as a conservative tracer of enteric virus removal in managed aquifer treatment systems.

Faecal pollution along the southeastern coast of Florida and insight into the use of pepper mild mottle virus as an indicator

“…Similar to previous studies, the results of this investigation suggest that PMMoV is a useful indicator of faecal pollution because its high concentrations in human wastewater circumvent the likelihood of false-negative results associated with the inefficiency of virus concentration and genetic purification methodologies (Rosario et al 2009;Hamza et al 2011;Haramoto et al 2013;Betancourt et al 2014;Kuroda et al 2015). Additionally, SIMPER analyses demonstrated that PMMoV concentrations contributed the most to the significant differences observed in water quality among inlet and ocean outfall sites, which suggests its usefulness as a domestic wastewater MST marker in comparison to the other faecal indicators and MST markers analysed.…”

“…In addition to measuring enterococci by both culturing and qPCR, the following microbial source tracking (MST) markers were analysed using (RT-)qPCR: pepper mild mottle virus (PMMoV; 100% sensitivity and specificity ranging from 90 to 92% for humans), human polyomavirus (HPyV; 100% sensitivity and specificity for domestic wastewater), Dog Bacteroidales (DogBact; 100% sensitivity and ≥55% specificity), CowM2 (≥98% sensitivity and 100% specificity) and two human Bacteroidales assays (HF183, 100% sensitivity and 60% specificity; BacHum, 100% sensitivity and 97% specificity; reviewed in Harwood et al 2013;Schriewer et al 2013). PMMoV has been proposed as an alternative indicator of human faecal pollution in Asia, Europe and the Americas (Rosario et al 2009;Hamza et al 2011;Haramoto et al 2013;Betancourt et al 2014;Kitajima et al 2014;Kuroda et al 2015) because its high concentrations facilitate sensitive detection in contaminated environmental waters and circumvent the false-negative results typically encountered with the use of reference viral pathogens (Rosario et al 2009;Hamza et al 2011;Haramoto et al 2013;Betancourt et al 2014;Kuroda et al 2015). PMMoV has been proposed as an alternative indicator of human faecal pollution in Asia, Europe and the Americas (Rosario et al 2009;Hamza et al 2011;Haramoto et al 2013;Betancourt et al 2014;Kitajima et al 2014;Kuroda et al 2015) because its high concentrations facilitate sensitive detection in contaminated environmental waters and circumvent the false-negative results typically encountered with the use of reference viral pathogens (Rosario et al 2009;Hamza et al 2011;Haramoto et al 2013;Betancourt et al 2014;Kuroda et al 2015).…”

Breakthrough of cyanobacteria in bank filtration

“…Thus, the higher log removals cannot be considered as an indication of better performance of bank filtration for indicator bacteria, especially considering their relatively small cell size. Given that E. coli were below detection limits in well water, it was useful to monitor a series of bacterial indicators since aerobic bacterial spores and total coliforms have also been shown to be appropriate indicators in filtration studies (Bauer et al, 2011;Betancourt et al, 2014;Jenkins et al, 2011). Cyanobacteria log removals may provide a more robust estimate of the potential log removals of other types of bacteria such as indicators given that all well water samples were above detection limits for cyanobacteria.…”

Rethinking the Significance of Reovirus in Water and Wastewater

“…Fout et al (1996) found ReoV to be the most common viruses in groundwater in the United Food Environ Virol States. Studies at managed aquifer sites also suggest that they may travel further than other enteric viruses in the subsurface (Betancourt et al 2014). However, their role in human disease is unclear, but given the role of bats in emerging zoonotic diseases such as SARS, Ebola, and MERS and zoonotic potential (including bats) of ReoV, additional studies on routes of human exposure are needed.…”