Conference Agenda

Clean Water Services is onboarding several methods to quantify viral removal, deactivation, and disinfection through our wastewater treatment facilities. Coliphages are viruses specific to E. coli that are commonly used as surrogates for human pathogenic viruses due to their similar fate and transport through wastewater treatment facilities as well as in the ambient environment. The US EPA is continuing the process of developing coliphage as fecal indicators for recreational water quality criteria. Coliphages are thought to be equal to the EPA’s currently recommended bacterial indicators when detecting fecal contamination, while providing more direct indicators of viral abundance in treated wastewater than bacterial methods. The current EPA method for quantifying coliphage is laborious and time-consuming, with sample processing requiring several days from starting preparation until final data becomes available. Optimized molecular methods are far faster and higher throughput, greatly reducing staff time required for monitoring and reducing time for data delivery from a scale of days to hours.

The goals of this project were to (1) onboard the EPA method for quantifying coliphage (EPA 1643, culture-based plaque assay) in our Water Quality Laboratory, (2) develop a multiplex droplet digital PCR-based molecular method to quantify coliphage based on published quantitative PCR methods, and (3) identify an optimal viral concentration method to aid in quantifying viruses in dilute samples (e.g., plant effluent). We will share our data on different viral concentration methods to prepare plant effluent for molecular analysis, and describe the influence that the initial viral concentration method may have on final viral quantification. The plaque assay and molecular methods will be used through the spring and summer of this year for influent and effluent characterization.

This presentation will detail the process of onboarding two different viral detection methods: the plaque assay and the molecular method, and a comparison of the data. This work is anticipated to be of interest to facilities looking toward viral detection methods in anticipation of future regulatory limits.