ST. LOUIS – New data from wastewater tests in the St. Louis area shows a stunning drop in COVID-19 viral load levels. Just last week, viral loads were at a near-record level. This week, those same tests indicate a 36% decline in the presence of COVID-19 genetic material; the first reported decrease in six weeks.

And while just one week of new data is not enough to determine if the omicron variant has peaked in St. Louis, this information tends to track with other data sources like confirmed COVID cases and hospitalizations.

It’s considered a noninvasive way to measure the presence of COVID-19 without relying on people to get tested.

The Missouri Department of Natural Resources (DNR) provides the wastewater treatment facilities with the kits, boxes, bags, and tubes in order for the lab to test the samples. Once they receive the data, usually within a matter of hours, they upload the information to the Missouri Department of Health and Senior Services (DHSS), who then passes it along to local health departments.

Wastewater testing involves collecting samples from treatment plants, then filtering and processing those samples, and finally measuring any trace amounts of COVID-19 genetic material. Samples are collected twice an hour at MSD’s seven wastewater plants across the St. Louis area, either by hand or by machine.

From those collections, samples go to a University of Missouri-Columbia lab for testing every week. DHSS tracks the findings as part of a federally-funded study.

Graph showing COVID-19 viral load from June 2020 to Jan. 2022
Courtesy: Metropolitan Sewer District, the Missouri Department of Health and Senior Services, and the Missouri Department of Natural Resources.

And while these tests do detect the presence of the virus, studies from the University of Missouri-Columbia show there is no risk of infection from wastewater. According to the Centers for Disease Control and Prevention (CDC), there have been no reported cases of COVID being spread through wastewater.

A DHSS spokesperson said wastewater testing continues to be one of two key programs the state continues to use to identify variants as they emerge. It’s also considered a leading indicator for infection rate data since the presence of COVID genetic material can be found in the waste of asymptomatic and presymptomatic carriers.