Pierce Health To Begin Tracking Wastewater For COVID-19

PUYALLUP, WA — The Tacoma-Pierce County Health Department, Washington State Department of Health and City of Puyallup have all teamed up to begin a new program that uses wastewater to better determine the community spread of COVID-19.

As the health department explains, more and more residents have been switching to taking their COVID-19 tests at home, especially now that those tests are easily accessible and often free. However, not everyone who tests positive at home ends up reporting their infection to the health department, and as a result they may not have an accurate assessment of the current community infection level.

"We know our case rate is rising. But by how much? Without accurate case reporting, we might not know the true size of case surges until hospitals are struggling with a wave of new COVID-19 patients," wrote TPCHD's COVID Project Manager, Jennifer Johnson.

One way they can get a better assessment on community spread that doesn't rely on self reporting, is by testing wastewater for COVID-19. Under the joint partnership, the health department has begun sampling at the Puyallup Water Pollution Control Plant. Another facility will be added soon, organizers said. Samples are collected twice a week and sent to the DOH for analysis. After about two weeks the health department will have enough data to study COVID-19 trends, meaning TPCHD should see its first results in early June.

While wastewater testing helps paint a broad picture of community spread, it does have some limitations as well. It can't track COVID-19 spread by neighborhood, ethnicity, age or socioeconomic variability., and weather conditions can dilute samples.

Still, any tool that helps health leaders understand more about community infection is big asset, Johnson said.

"Our goal is to provide you with information to keep you and your family as safe as possible," Johnson wrote. "Even with these limitations, data from wastewater testing combined with other COVID-19 data give us, local healthcare facilities and you valuable information."

Tracking community transmission is especially important right now, as Pierce County is seeing a new surge in COVID-19 infections that put the county into the CDC's "medium" risk category.

Pierce County is not alone in seeing higher case counts. The statewide case count has quadrupled over the last two months, and other large counties like Snohomish County and King County have also recently been bumped into the medium bracket.

While the health department waits for the new data to come in, they're urging everyone to continue following COVID-19 safety guidelines like:

• Wear a mask in public indoor spaces.
• Stay home if you're sick.
• Get tested if you experience symptoms or were exposed.
• Get vaccinated or get your booster if you're already vaccinated.