Sampling of Utah wastewater shows rise in coronavirus

The Utah Department of Health is using wastewater to track the spread of the coronavirus. (Winston Armani, KSL-TV)

SALT LAKE CITY — COVID-19 is intensifying again in our communities. You can see it in the clinical testing data, and the Utah Department of Health can even confirm it in our sewage.

Every time we flush the toilet, the Utah Department of Health gathers more data on COVID-19 in our communities.

A year ago, scientists in Utah discovered they can track the coronavirus in our sewage. Now, they use that data to identify trends and confront the virus.

"We have been seeing very consistent increases certainly through August," said Nathan LaCross, who manages the wastewater surveillance program for the Utah Department of Health.

Shortly after COVID-19 emerged in Utah, researchers started testing incoming wastewater for the coronavirus at 10 treatment plants statewide.

"We're seeing broad and really pretty sustained increases just about everywhere that we're sampling in the state," LaCross said. "That is certainly of concern."

High levels of coronavirus in the wastewater indicate higher levels of COVID-19 cases in those communities.

"It's reminiscent of the patterns that we saw last fall, as well, where we also saw broad increases through much of the state," the program manager said.

The surveillance acts as a leading indicator, even an early warning system about the level of virus in the community.

"Increases in the wastewater often precede corresponding increases in cases in that same area. So it often provides us with a number of days of extra time to respond that we wouldn't otherwise have," LaCross said.

A look at the data at shows increases in Salt Lake City and other areas indicated in red. Testing shows the presence of coronavirus in the wastewater in Tooele, among other communities, but not trending up there.

"The earlier that we are able to intervene in areas that have increasing transmission, the more effective those interventions are going to be."

Wastewater surveillance doesn't just monitor people who decide to get tested. It monitors everyone who uses the system. Health officials get anonymous signals from the waste of those who are symptomatic or asymptomatic.

"They may not even know they're infected," LaCross said. "But they may still be able to transmit it. As long as they're shedding the virus in the sewage, we're going to be able to detect it."

Community-wide sampling helps independently corroborate what they're seeing in clinical testing. It helps them estimate the prevalence of infection in a community without testing everyone.

"We're seeing trends that are very similar to what we saw last fall," LaCross said.

Right now, they're sampling 33 sites in the state twice a week, which covers nearly 90% of the state's population.

"Which is a huge number of people to sample, especially for the resources that we're putting into it," the program manager said.

You can find the data for the wastewater treatment plant in your community at

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Jed Boal


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