Sewage has become a COVID-19 tool. American colleges and universities have struggled to cope with the COVID-19 epidemic as students returned to campus in 2020. Most colleges are unable to provide widespread testing and contact tracing. Testing all students, faculty, and staff on a campus is prohibitively expensive.¹

As a result, many colleges and universities have turned to a different approach. Those infected with COVID-19 shed viral particles in their waste.² Evidence of these viral particles can be tested by sampling wastewater.³ Testing sewage offers a reliable method for identifying outbreaks and is cheaper and easier to administer than a mass testing and contact tracing program

The reliance on wastewater testing during a pandemic makes sense at a time when no national program on mass testing and contact tracing exists.⁴ And as COVID-19 is likely to affect the population well into 2021, state and local governments have considered or started sewage testing.⁵ But emergency measures have a tendency to stick around after the crises that prompted them diminish. COVID-19’s public health crisis will end. But the incentives to monitor wastewater will continue.⁶

This essay argues that sewage testing will outlive the pandemic and become a part of a general policing surveillance infrastructure. We risk adopting this surveillance method without taking care to assess the legal and policy questions raised by its use. Wastewater can provide early clues not just for COVID-19 outbreaks, but also for the presence (and assumed use) of opioids, methamphetamines, and other illegal drugs.⁷ Sewage testing at the University of California, San Diego, recently led to an alert that an infected person was “someone who used a restroom [at a specified residence hall] from 6 a.m. and 9:30 a.m. on Sept. 2.”⁸ Now replace “methamphetamine” for “COVID-19.”

Systematically looking for evidence of criminal activity in sewage “may be a goldmine for law enforcement authorities.”⁹ COVID-19 is the current object of wastewater surveillance. However, the use of sewage testing now—by public universities, counties, and other government entities—can be readily repurposed from the detection of COVID-19 to other substances of interest to law enforcement agencies.