We are more than halfway through the year and coronavirus is still dominating headlines. Most recently, the Water Research Foundation (WRF) issued a set of recommended best practices for wastewater surveillance of the genetic signal of SARS-CoV-2 in sewersheds as an indication of the presence of COVID-19 within a community. The information, provided by global experts, offered insight on the current state of knowledge on wastewater sampling, molecular genetics tools, interpretation of results, and communication of this information for use by public agencies and utilities.
Wastewater surveillance is not new. The practice has been used to successfully monitor illicit drug use in some communities, for example. Now, with a number of recent studies showing high levels of viral shedding in fecal samples from COVID-19 patients, sewage could predict the location of the virus’ next outbreak. Since shedding occurs early in the disease’s progression, well before patients show any symptoms, a community’s wastewater could provide an indication that infection levels are rising in the area, even before individuals have been tested.
Several academic research groups and private companies have begun sampling and monitoring wastewater for coronavirus markers in recent months, and even the U.S. EPA is joining in. In a six-month pilot project with the city of Cincinnati, Ohio, the agency is hoping to develop a coronavirus test method to “inform public health decisions,” an EPA scientist said. Working alongside the Metropolitan Sewer District of Greater Cincinnati, EPA scientists are seeking to learn how long the virus lives in wastewater, how to test sewage consistently for the virus, and how to factor wastewater systems where sewage is diluted by industrial waste or stormwater before reaching the treatment plant into this sort of research.
It’s worth noting that the actual wastewater poses no threat to treatment plant employees, since standard methods of treatment are sufficient to kill the virus in wastewater.
And, while wastewater surveillance is promising, it is by no means a silver bullet in our defense against coronavirus, as WRF’s research states: “While the use of wastewater surveillance to identify a decrease in disease occurrence is also technically feasible, it may be complicated by the persistence of fecal shedding of SARS-CoV-2 RNA long after individuals have recovered from infection. In other words, wastewater surveillance is an effective leading indicator of COVID-19 emergence but may be a lagging indicator of subsidence, at least relative to clinical data.”
Though it has complicated some of our work, the pandemic has created greater public and media interest in wastewater operations.
“A focus on effective communication strategies with the public health community, elected officials, wastewater professionals, the media, and the public is a critical component of efforts to utilize wastewater surveillance for tracking [disease] trends,” WRF CEO Peter Grevatt recently told me.
Among WRF’s next steps, Grevatt said, are efforts to provide a standard method of testing across wastewater utilities.
And who could be better than water professionals to communicate these complex issues to a variety of audiences? While this is certainly a strange time for all of us, the work we do is more important than ever, and people are listening. So, talk the talk, and engage as often as possible with your community stakeholders about what you do. We are all in this together.
Thanks for reading! WW
