When at-home COVID-19 tests are hard to find and lines at testing centers stretch on for hours in Marlyand, what you flush down the toilet could be the next best thing to determine how fast the coronavirus is spreading in the southeast .

That’s right: Public health officials in counties across the country are turning to your wastewater to determine the prevalence of COVID-19 in communities.

In fact, experts think sewage might be the key to better understanding the overall public health of cities and neighborhoods, especially in underserved areas that don’t have equal access to care, according to an NBC News report.

“Every time an infected person uses the toilet, they’re flushing this information down the toilet, where it’s collecting and aggregating and mixing with excrement from thousands of other people,” Newsha Ghaeli, a co-founder and president of Biobot Analytics, told NBC News.

“Even if you can’t access a test, you’re still pooping,” Ghaeli continued. “It doesn’t depend on you having access to health care or health insurance.”