POTSDAM — For two months, a team of local researchers has collected wastewater samples from colleges and municipal treatment facilities every week, extracting genetic material of the novel coronavirus.
Developed at Clarkson University late this summer and launched in October, the wastewater monitoring program has facilitated regular testing of samples from Clarkson, SUNY Canton, St. Lawrence University, the North Country School in Lake Placid and the villages of Canton and Potsdam.
Samples have been collected every Monday and Thursday in St. Lawrence County, and every Sunday from the North Country School. A total of about 400 samples have been drawn at the north country sites, all brought to Rowley Laboratories at Clarkson, where the testing process takes place and results are rendered within 12 to 24 hours.
With college students now home until January, Shane W. Rogers said, campus wastewater surveillance will relax over the break, but municipal sampling will continue.
A Clarkson associate professor of civil and environmental engineering, Mr. Rogers has led a team of young scientists, comprised of post-doctoral Research Associate Hema Ravindran, graduate lab technicians, undergraduate interns, engineering students and Geographic Information System students and faculty coordinating mapping of sewer and sampling networks.
“We’ve been fortunate to have very low levels this fall — until very recently,” Mr. Rogers said, adding that the current surge in COVID-19 cases from individual testing on campuses and in the county are reflected by increased concentrations of the virus in wastewater samples.
Infected individuals, he said, typically start shedding the virus a few days before they show symptoms, or if asymptomatic, without even realizing they may be positive. Detecting traces of the virus in wastewater — an early warning sign for case escalation — represents the “undercurrent of undetected virus” in communities.
“People need to realize that,” Mr. Rogers said. “The virus is here.”
Wastewater testing for the novel coronavirus has been launched on college campuses and in municipalities around the world, as the virus is known to shed in the feces of infected individuals.
On campuses, the focus has been monitoring residential buildings for potential clusters where increased individual testing should be targeted. When cases were identified and students placed in quarantine halls this semester, Mr. Rogers said, observable increases in virus concentration in wastewater were noted mid-infection, as were decreases when quarantined students began to recover.
Municipal wastewater testing is less targeted and samples can be more inconsistent because of rain dilution and groundwater infiltration, but is useful for tracking general changes in the virus’ presence.
In Canton, detectable traces of virus were not identified in village wastewater samples until early November, village Mayor Michael E. Dalton said this week. Keeping track, he said, is especially helpful for reinforcing the importance of community-wide adherence to public health measures like ever-important mask wearing, social distancing, virtual gatherings and good hygiene.
About 1,500 metered lines — not reflective of the number of users as several users can be metered together — all flow to the village wastewater facility adjacent to Partridge Run Golf & Country Club on Sullivan Drive.
With sampling systems already in place for health and environmental compliance at municipal facilities, collection is convenient for Clarkson researchers, Mr. Rogers said. On campuses, above ground, insulated sampling sites have been set up and are now being further winterized.
On collection days, the samplers pump wastewater into a container housed in a controlled temperature station. Internal controls maintain a temperature of 4 degrees Celsius, about 39 degrees Fahrenheit. The samples are kept chilled to slow virus decay, but not frozen, as repeated freezing and thawing can lead to faster virus degradation, Mr. Rogers said.
With fecal matter diluted by sink and shower drainage and flushed fluid, the samples are reconcentrated and virus RNA is extracted, amplified and read in the lab. The process, Mr. Rogers said is essentially the same process used to test nasal swabs, with calibration of equipment adjusted for virus RNA detection in sewage rather than people.
This semester’s data will be used for wastewater epidemiology research and to evaluate the overall process for potential improvements to Clarkson’s methods, the professor said. Regular sampling of campus wastewater is set to resume when students return for the spring semester.
The program, he said, was designed “as another layer of protection” to supplement continued individual testing, sanitation procedures and social expectations.
COVID-19, the respiratory disease caused by the SARS-CoV-2 virus, or novel coronavirus, has killed more than 260,000 people in the United States, and about 34,000 in New York since February.
In St. Lawrence County, the Public Health Department reports 153 active cases and nine deaths as of Wednesday.
“The best advice is for everyone to pay attention to the possibility that they, their family or friends may be carrying the virus,” Mr. Rogers said. “Unless everybody does their part, we won’t be able to get it under control.”