University of Minnesota tests whether coronavirus is moving into drinking water

Researchers plan to test Minnesota's groundwater systems to determine whether the novel coronavirus that causes COVID-19 is lurking in the damp cold and slipping into any drinking water.

The sampling will start as soon as the project financing is approved by Gov. Tim Walz, with the first results expected by the end of May.

University of Minnesota researchers are concerned the virus remains in septic systems and sewers after infected people flush it down drains. From there the virus may be leaking through cracks in sewer pipes and the normal discharges of septic systems and work its way into drinking water.

That doesn't present a problem to much of the state, where groundwater in community wells is disinfected with chlorine or ultraviolet light, for example, and treated many times over before it is ever used for drinking.

But it does pose a risk for people who rely on private wells and, to a lesser extent, to those who live in rural communities where water utilities don't disinfect water before it is piped to homes, said Raymond Hozalski and Timothy LaPara, the U microbiologists leading the project.

About 1 in 5 Minnesotans, or around 1 million people, rely on private wells for their water.

Health officials say most private well owners don't disinfect, and they estimate there are about 270 community water systems around the state that don't disinfect, most of them in rural areas with fewer than 1,000 people.

"We fear these are susceptible to contamination and there is an opportunity for these pathogens to get people sick," LaPara told legislators Thursday.

State health officials said they don't see a big threat.

For one, the virus is fragile in the environment, which is why a good hand-washing with soap can get rid of it, said Anita Anderson, an engineer with the Minnesota Department of Health's drinking water protection program. Plus, water is not the primary way infection occurs. It's person-to-person contact, she said.

Anderson said "it's not completely implausible" that the U study would turn up evidence of the pathogen, but she doubts levels would be high enough to pose a big health risk. There's no evidence that anyone has contracted COVID-19 through drinking water, she said.

There are no state or federal requirements to disinfect, she said.

"People should still be using their drinking water as normal right now, especially to wash your hands and to drink," Anderson said.

The Centers for Disease Control and Prevention (CDC) maintains that the coronavirus has not been detected in drinking water. "Conventional water treatment methods that use filtration and disinfection, such as those in most municipal drinking water systems, should remove or inactivate the virus that causes COVID-19," it says on its website.

The CDC also says that available information suggests that "standard municipal and individual septic system wastewater treatment practices should inactivate the virus that causes COVID-19."

The new U research is being paid for with $59,000 from the state's lottery-backed Environment and Natural Resources Trust Fund. The commission that directs the spending approved the money at a meeting Thursday, drawing from an account for "emerging issues." Spending for those projects requires approval by the governor.

The request was sent to Walz, and his staff indicated he would approve it, said Becca Nash, director of the 17-member commission.

Nash said that the official guidance has been that public water supplies have robust systems for disinfecting drinking water.

"There's a gap in understanding what happens with the water that's not treated," Nash said. "I think these guys are on the front lines."

While it's unclear how long this new coronavirus remains active in the environment, there is plenty of evidence that viruses can survive months — even years — in groundwater aquifers, LaPara testified to the commission Thursday. He called it a "curiosity."

"We don't know why, but viruses, if you want to preserve them, the conditions of a groundwater aquifer are almost ideal for preserving these things long term."

"That leads to a public health concern specifically with undisinfected water supplies — some public and particularly private."

Recent research in other parts of the world, such as Australia, have found that "substantial quantities" of the coronavirus are making it into untreated municipal sewage, Hozalski said.

In Minnesota, the vast majority of all that sewage eventually winds up at a treatment plant where the virus would stand little, if any, chance of surviving.

The potential problem comes from leaking pipes and from intentional leaks from private septic systems designed to slowly discharge waste into the ground. In either case, the virus could travel into groundwater that gets tapped for drinking.

Researchers in Wisconsin found that numerous viruses from human fecal matter are being "recycled" into drinking water that is not disinfected, Hozalski said.

The speed of the work will depend on how quickly researchers can get the equipment they need. They will try to test water supplies from as wide a swath as possible across the state, focusing on geographies most at risk, such as the porous limestone regions of southeastern Minnesota where wastewater can quickly reach groundwater. LaPara told the commission Thursday that the research team is coordinating with state health officials who will help communicate results to the public.

"This is sensitive information, obviously," LaPara said. "And we do not want to communicate the information that we get and obtain in a way that would lead to public panic or even misinformation."

Jennifer Bjorhus • 612-673-4683 jennifer.bjorhus@startribune.com

Greg Stanley • 612-673-4882 greg.stanley@startribune.com