This is an excerpt from the June 8, 2020, episode of What's Up With Water. This episode reports on sewage surveillance as a way to monitor the new coronavirus. It’s attracting a lot of attention, but has some obstacles to overcome before it is widely used for public health decisions. In hundreds of cities worldwide, health departments and researchers are turning to sewage to better understand the spread of the virus in their communities. This is possible because people infected with SARS-CoV-2 shed particles of the virus in their stool.