Lines must drawn: public health vs privacy

Movie stars and criminals have learned the hard way that they shouldn't expect any privacy rights for things that go into their trash cans.

It has been well settled under federal law for decades that there is no reasonable expectation of privacy in garbage left at the "outside curtilage" of a home or business. California v Greenwood, 486 U.S. 35 (1988). Justice Byron White famously wrote in the opinion, "It is common knowledge that plastic garbage bags left along a public street are readily accessible to animals, children, scavengers, snoops, and other members of the public." The opinion reasoned that the plaintiff had left his trash for collection in a public area, and that any claimed expectation of privacy in discarded items is not objectively. California law concurs.

But what about things that go into the toilet? Turns out there may be no privacy there either. For years, cities have been analyzing wastewater to determine the presence of chemicals, heavy metals and microorganisms so the water can be treated for human consumption or release.

These practices gained greater public notice recently when governments began using wastewater analysis to determine levels of COVID-19 in their communities. Last year, the U.S. Department of Health and Human Services and the Centers for Disease Control and Prevention contracted with AquaVitas, LLC, a wastewater analytics company, for a nationwide study of wastewater in the U.S. The study analyzed wastewater from hundreds of treatment plants in at least 42 states representing approximately 30% of the U.S. population.

HHS says that wastewater testing predicts COVID-19 cases five to 11 days ahead of clinical testing. Such predictive analysis gives public officials a planning advantage and the ability to quickly target a response, according to HHS. Wastewater testing also assists COVID-19 prediction for communities lacking testing facilities or supplies.

The city of Tempe, Arizona has its own wastewater testing program. In conjunction with scientists from Arizona State University's Biodesign Institute, Tempe has created a citywide wastewater analysis program that tracks fluctuations in COVID-19 levels on a weekly basis. The analysis yields the number of COVID-19 gene copies per liter of water in seven collection areas throughout the city.

Tempe is quick to point out that wastewater analysis does not identify the source of COVID-19 in wastewater and does not provide an exact indicator of the number of people who "contributed" the COVID-19 materials. But it could.

Wastewater could be collected from a single neighborhood, building or home. While collecting wastewater to help public health officials track COVID-19 levels during a pandemic may be acceptable, using such techniques to screen for illegal drug use or signs of other activities or personal characteristics might not. It's not hard to imagine how such data could be misused by insurance companies to raise rates or deny coverage for targeted areas of a city, as an example.

The new and advanced ability to extract and analyze genetic material from wastewater poses clear privacy concerns. Currently there are no rules on how granular a wastewater study can be, who owns genetic data extracted from wastewater, or how such data can be used.

California has one of the most expansive privacy laws in the country -- the California Consumer Privacy Act, which took effect Jan. 1, 2020. The CCPA provides privacy protection for biometric information, defined as "an individual's physiological, biological, or behavioral characteristics," including DNA, imagery of the iris, retina, fingerprint, face, hand, palm, vein patterns, and voice recordings, faceprint keystroke patterns or rhythms, gait patterns or rhythms, and sleep, health, or exercise data that contain identifying information. Cal. Civ. Code Section 1798.140(b).

Presumably the CCPA covers an individual's poop. But it only gives consumers the right to control the collection and use of personal information for marketing purposes by businesses engaged primarily the collect of data for marketing that have gross annual revenues in excess of $25 million. Cal. Civ. Code Section 1798.120, 121; 1798.140(c). It doesn't protect against collection or use of data from wastewater by governments or other non-commercial entities.

Many might argue that not much sensitive information could be gleaned from human waste, so who cares. Wastewater analysis, however, could reveal unique characteristics. For example, an investigator could identify individuals undergoing medical treatment that uses radioactive materials or medical imaging contrast agents according to experts.

Unlike commercial transactions where a person understands he or she is generating personal data, using the toilet appears to be a private experience. Moreover, it's impossible to avoid "contributing" biological data. There's no equivalent to shredding paper before it goes to the trash can. Right now, anyone with the expertise is free to peer into your waste stream without your knowledge or consent.

If we can use technology to combat deadly viruses, we should. But before wastewater analysis technology becomes any more widespread, lines should be drawn between public health monitoring and individual surveillance. 