City to test sewage for COVID-causing virus

TRAVERSE CITY — Testing sewage for the virus that causes COVID-19 could provide an early warning of infection flare-ups in the Traverse City area.

That’s why the city, Grand Traverse County Health Department and the state are partnering through Dec. 30 to look for the virus within a system that serves roughly 45,000 residents across the city and six townships, not to mention commercial users.

Their data will contribute to a statewide effort to track the virus over broad areas by testing in numerous other sewer systems, county health department Environmental Health Director Dan Thorell said.

Determining the presence and prevalence of the disease in certain areas provides another sorely needed data point beyond confirmed cases and positive test rates from individual swabs, Thorell said.

“So over time, I think it’s going to be very useful to kind of get a baseline of what’s going on when you first start the study, and then watching those trends over time to see what’s actually happening out there, so it’s just another tool in the toolbox,” he said.

The data from the pilot project could show the health department where more individual tests or targeted education efforts are needed, he said.

Weekly sampling from 10 points of the sewage system already started and analyses begin next week, Elizabeth Hart said. She’s project manager for Jacobs, the company that operates the Traverse City Regional Wastewater Treatment Plant.

The plant treats sewage from the city and Acme, Blair, East Bay, Elmwood, Garfield and Peninsula townships, as previously reported.

Up to $172,000 in grant money will pay for the analyzer equipment, a hood for handling samples and a special freezer for them, Hart said. It’ll also cover the cost of reagents and the labor involved in the research.

“I think that everything we can learn about this virus that’s affecting everybody so dramatically could help to even possibly save lives in the future, so I think that any way that we can possibly better understand how it lives within our community, the better off we’ll be,” she said.

Federal Coronavirus Relief Fund money paid for the grant, as is the case for cities around the state taking part in the project, said Shannon Briggs, a toxicologist for the state Department of Environment, Great Lakes and Energy’s Water Resources Division.

The list of participants wasn’t final as of Friday but should be announced shortly, Briggs said.

A few Michigan cities tested sewage for the virus earlier in the year, Briggs said. The idea of the surveillance program is to do the same in cities across the state, and make sure each participant’s using the same methods so the results are comparable.

Checking sewage for SARS-CoV-2, as the virus behind the pandemic is named, gives an earlier warning because people shed the virus in their feces three to 10 days before symptoms show, Briggs said.

“So that’s where people are looking at wastewater monitoring as an earlier detection of how is a virus impacting a population, because one of the other things that’s happening is, when we monitor this virus in wastewater, they can quantify the virus, so it’s not just positive or negative,” she said.

Knowing the quantity of the virus within samples provides the kind of data that scientists can use to build forecasting models, Briggs said.

The equipment uses a technique known as droplet digital polymerase chain reaction, which can identify genetic material to pinpoint a specific virus and not just SARS-CoV-2, Briggs said. That means health departments can use the equipment for other purposes, like identifying the source of fecal contamination at beaches.

Thorell said that kind of source tracking could show if animal droppings are to blame for repeated beach closures, or something else, like sewage getting into a storm drain.

“The idea is to get proficient in the use and in the knowledge surrounding PCR methods, and at the end of this project looking for SARS-CoV-2, to be able to keep it to use it for other things,” he said.