The COVID-19 pandemic may feel like a distant memory for most Pocatello residents, but something unusual is showing up in the city’s wastewater — and public health officials are paying attention.

According to data released last week by the Centers for Disease Control and Prevention’s National Wastewater Surveillance System, Bannock County is currently listed as having very high levels of COVID-19 in its wastewater — the highest category on the CDC’s five-tier scale.

It’s worth noting that the CDC’s designation for Bannock County is based entirely on testing conducted in Pocatello, which is the only city in the county participating in the national surveillance program. No other communities in Bannock County are being tested. Whether the rest of the county mirrors what Pocatello’s wastewater is showing is unknown — though given that Pocatello is by far the county’s largest city and its regional hub, the numbers are likely representative of broader trends in the area.

Pocatello is one of only five sites in the entire country currently showing very high COVID levels in wastewater, making it a significant outlier not just within Idaho but nationally.

The readings are striking not only because they stand in sharp contrast to the low COVID activity being reported locally in terms of actual cases and hospitalizations, but because the rest of Idaho is showing low to very low COVID levels at its other four wastewater testing sites. With COVID activity low in most areas of the country as of early June, Pocatello’s very high reading stands out as one of the most elevated in the nation.

“Very high” is the CDC’s most severe wastewater classification, indicating the highest measurable concentration of COVID viral material in the wastewater system. Wastewater monitoring can detect the virus spreading from person to person within a community earlier than clinical testing and before sick people go to their doctor or hospital — and it can also detect infections in people who have no symptoms at all.

Idaho currently has five locations that test wastewater for COVID-19. Two are in Ada County, one in Latah County and one in Kootenai County. Pocatello — the county seat and largest city in Bannock County — is the fifth testing site and currently the only one in the state showing very high levels.

The disconnect between the wastewater data and the reported case numbers is puzzling but not necessarily alarming — at least not yet. Southeastern Idaho has reported approximately 115 COVID cases since mid-November 2025, with fewer than 10 cases reported in all of May. Only two local people, both Bingham County residents, have died of COVID so far this year.

Local health officials are currently characterizing COVID activity in the region as low. No surge in hospitalizations has been reported.

That gap between high wastewater readings and low reported cases isn’t unusual and can happen for several reasons.

People infected with COVID shed the virus in their feces — sometimes for days before developing symptoms or ever seeking testing. Historical trends show that when COVID levels increase in wastewater, COVID infections in the community typically increase five to seven days later. In other words, wastewater is an early warning system — not a current case count.

The low case numbers may also simply reflect the reality that fewer people are getting tested for COVID than during the height of the pandemic. Home tests don’t get reported, and many people with mild symptoms never seek medical care.

The COVID circulating in the community may be more widespread than the official case count suggests.

Pocatello’s elevated readings are also coming at a time when COVID is quietly on the rise nationally. As of early June 2026, the CDC has noted it remains possible that there could be larger increases this summer, particularly if a variant that the immune system no longer recognizes becomes more common. Summer COVID spikes have become a regular pattern in recent years, with the highest levels typically concentrated in the Western United States. The good news, public health experts note, is that deaths and hospitalizations have been gradually declining across the U.S. each season even as COVID continues to circulate.

Local health officials have not yet issued any precautions to Southeast Idaho residents in response to the very high COVID levels in Pocatello’s wastewater.

But given the elevated wastewater readings, local residents should take some basic precautions — particularly those who are elderly, immunocompromised or have underlying health conditions. Staying current on COVID vaccinations and updated boosters is the most important step. Those at higher risk should consult with their health care provider about whether additional precautions make sense for their situation. Masking in crowded indoor settings is worth considering, particularly when visiting vulnerable family members. If you feel sick, test before attending gatherings. COVID tests remain widely available at pharmacies and clinics throughout the region. Improving ventilation in indoor spaces when possible also reduces risk.

The very high wastewater reading in Pocatello is an anomaly that warrants monitoring. Whether it signals a coming uptick in cases — as wastewater data historically has — or represents a temporary spike that recedes without a corresponding wave of illness remains to be seen. Increased COVID wastewater levels indicate a higher risk of infection, but the data alone cannot tell us how many people are infected or predict with certainty what comes next.

What public health officials and residents can do is watch the numbers closely, take reasonable precautions and remember that the wastewater system is telling us something — even if we’re not entirely sure yet what that something means.

For up-to-date COVID wastewater data, visit the CDC’s National Wastewater Surveillance System at cdc.gov/nwss. Southeastern Idaho Public Health can be reached at 208-233-9080.