Water Resources Research Act Program

Details for Project ID 2018HI480B

Evaluation of Pepper mild mottle viruses as a sewage marker in Hawaii

Institute: Hawaii
Year Established: 2018 Start Date: 2018-03-01 End Date: 2019-02-28
Total Federal Funds: $20,017 Total Non-Federal Funds: $56,057

Principal Investigators: Marek Kirs

Project Summary: Currently microbial water quality is evaluated using fecal indicator bacteria such as total coliforms, Escherichia coli and enterococci, as there are too many sewage-borne pathogens to target with individual tests. While abundant in sewage, these bacteria are also abundant in animal feces as well as in extra-enteric environments such as tropical soils. There is need for methods which can reliably use to determine contamination source as the health risk associated with indicator bacteria depends from the source. Also appropriate management techniques can be applied once the source of contaminants has been identified. Pepper mild mottle viruses (PMMV), which like noroviruses contain single stranded positive sense RNA, have been suggested as sewage specific markers due to high prevalence and concentrations in human feces and sewage. A study of twelve WWTPS throughout the coastal US has shown that PMMV concentrations in all wastewater treatment plants exceeded one million copies per ml. These concentrations are much higher when compared to any human viruses proposed as sewage indicators. Furthermore, in contrast to human enteric viruses for which distribution is dependent on current illness rates and tends to exhibit seasonality, the concentration of PMMV appear to exhibit no seasonality and remain stable in urban wastewater throughout a year. Due to the high concentrations and stability in sewage, utilization of PMMV as health risk indicators and microbial source tracking markers has been recommended. In addition, PMMV have been recommended as a tool study virus transport as well as efficiency of wastewater and drinking water treatment. Also utilization of PMMV as drinking water quality indicators have been suggested. Although the potential to utilize PMMV as sewage-tracers is high, the concentrations of PMMV in Hawaii wastewater samples (WWTP, cesspools) have not been determined. Also, when considering PMMV as surrogates for enteric RNA viruses such as norviruses, there is a need to identify the die-off rates as well as the effectiveness of current treatment methods to remove these types of enteric viruses, as these parameters are expected to differ from the ones established for indicator bacteria.