Yarmouth Tests Wastewater to Understand Local Covid-19 Trends
With state/federal grant funding, Yarmouth is testing our town’s wastewater for signs of the COVID-19 virus.
Who else is doing this?
While the testing technology is fairly new, it’s now being used in a number of towns and cities including Augusta, Portland, and Boston.
Montana’s Healthy Gallatin Program has been testing waste water in Gallatin County for COVID-19 since March. They capture this data weekly for Bozeman, Big Sky, and West Yellowstone.
It is also being used at the University of Arizona, where it detected evidence of the virus in a student dormitory’s wastewater and allowed the University to intervene very early to prevent a larger outbreak.
What does wastewater testing tell us?
People pay little mind to a toilet flush once its contents disappear into the maze of pipes that lead to a municipal sewage treatment plant to be processed. But that wastewater is a valuable resource in combatting the COVID-19 pandemic, according to researchers at Montana State University.
The results of their weekly tests suggest that wastewater measurements are a reliable early indicator of the local presence of the virus and disease. Presence of COVID-19 virus in wastewater tracked well with outbreaks of the disease in the Montana cities they tested.
Because asymptomatic or pre-symptomatic individuals can be infected with COVID-19 virus and spread the virus and disease for a week or more before showing symptoms, early detection of increased levels of the virus in wastewater could help health officials identify potential outbreaks of COVID-19 and intervene early to isolate infected individuals, quarantine contacts, and implement social distancing and other measures to reduce virus transmission before a tide of sickened patients seek testing and medical treatment.
This project is undertaken in collaboration with the Yarmouth Community Coronavirus Task Force and the Town of Yarmouth, with funding from the Keep Maine Healthy program. Yarmouth tests wastewater weekly and will continue to do so for the next six months.
The wastewater sample is gathered at the town level and not tied to any specific site. The level of the COVID-19 virus over time will be useful as an indicator of the presence of COVID-19 in our community during this time period.
The testing began the week of 9/21/2020.
The process
The process is fairly simple. Samples are captured at the Yarmouth Wastewater Treatment Facility and sent to a lab at St. Joseph College to isolate RNA (genetic material) from the wastewater and then test the RNA for SARS-CoV-2 specific RNA (SARS-CoV-2 is the coronavirus that causes COVID-19).
Two parts of the nucleocapsid gene (N1 and N2) from the SARS-Co-V-2 genome must be found in the sample to be considered positive.
When the virus is found in a sample, the lab estimates how many viral particles are present. This helps us understand whether viral levels found in wastewater are going up, staying the same, or going down from week to week.
Limitations of the information
Testing results only represent the people in the Yarmouth community who use the wastewater system—not those on private septic systems–so that wastewater results do not reflect all new infections and cases of COVID-19 in the town.
Wastewater testing is one promising piece of the complex COVID-19 puzzle. We’re still learning about this new virus, how it spreads, and how our actions impact the number of new confirmed cases.
The Yarmouth Community Coronavirus Task Force members, the town leadership, and the health officer will use these test results, along with many other pieces of information, to decide how best to support the health of the town. More information will be available as the project progresses.