GAMBIER – A week after tests of Gambier’s wastewater hit its highest numbers yet for the presence of COVID-19, the village’s positive cases for the virus tripled.
Municipal authorities and public health officials are looking at the use of wastewater testing as something of an early warning system for spikes in the virus.
Joan Slonczewski, a professor of biology with Kenyon College, said Gambier’s tests so far indicate that wastewater sampling may be able to show an outbreak is underway even before medical testing results are known.
Ohio National Guard specialists Courtney Murphy, left and Camilla Forbush conducts a swab test and specimen collection during a drive-thru COVID-19 test at the Knox County Fairgrounds on Saturday, August 8. No additional testing sites or date have been announced for the remainder of August.
[cvl]
“We may propose that we predicted a spike in (cases),” Slonczewski said. “It looks as though the wastewater tests rise a week ahead of the cases.”
KPH Health Commissioner Julie Miller said the health department’s environmental health division is investigating how the tests can be used.
“We’re watching it to learn more about it and what we can gain from it,” Miller said. “We’re looking at it from the preventative perspective, what it can allow us to do.”
If KPH can see a surge ahead of medical test data, it can see where to focus resources and urge heightened use of preventative measures, such as face masks.
Nate Overholt, KPH director of environmental health, said his division is starting with the technical aspects.
“It’s more about getting a better grasp of what is being done and how it is being done, what data is being provided,” he said.
Gambier and Mount Vernon started testing months ago. At first, Gambier was taking one sample a day, Village Administrator RC Wise said. That only reflects what is coming through the plant at that moment, however. They now take composite samples, drawing from wastewater twice on one day of the week to get a broader reading.
Mount Vernon has also gone to composite sampling, drawing from the wastewater every two hours for one day a week.
There are still some unanswered questions about the testing. Slonczewski noted that it is “highly experimental.” Mount Vernon Utilities Superintendant Mathias Orndorf said that the treatment plant also accepts wastewater from haulers who pump septic systems and portable toilets, and it is not known how the water, coming from outside sources, could affect test results. He noted that there were probably “one or two” samples that were taken while haulers were dumping wastewater at the plant.
All of Gambier’s tests have found significant traces of COVID-19. Mount Vernon’s testing, however, has found less than trace amounts despite their having 120 positive identified cases to date. A problem may be that 17,000 people are living in the city and that such a large population might dilute traces of the coronavirus.
KPH’s case data numbers are identified by zip code, which means the positive cases that count for Gambier or Mount Vernon could be residing outside town limits and do not use the wastewater systems.
Gambier’s numbers are predicting fewer or no cases the next time KPH reports. After hitting the spike on July 25, the next week’s results saw a sharp drop, Slonczewski said.