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When it comes to tracking COVID-19, SMCSD is flush with data

District Lab Technician Randy Hart preparing samples for the UC Berkeley COVID-19 study.

As part of the ongoing efforts to detect and stop the spread of COVID-19, the District is participating in a UC Berkeley study to test for the novel coronavirus in wastewater. In addition to airborne droplets, coronavirus can be shed through the digestive tract and into our sewers. Researchers hope that by monitoring for dead COVID-19 cells in wastewater they can help identify outbreaks in their very early stages, possibly even before they show up in regional case counts.

Wastewater Does Not Spread COVID-19. Although viral particles can be detected in wastewater, the Centers for Disease Control and Prevention (CDC) have assured the public that “there is no information to date that anyone has become sick with COVID-19 because of direct exposure to treated or untreated wastewater.”

Early Warning System. Because the testing samples pooled wastewater from the entire service area, it cannot identify individual homes or businesses that might be the source of detected virus particles. So, while it cannot identify individual infections, like a nasal swab, centralized wastewater testing could provide a safe and unintrusive early warning system to help county officials understand where COVID-19 might be spreading in the community, and how fast: the more virus detected in the wastewater, the more likely a widespread outbreak could be underway. Early detection can help public health officials make decisions about how to allocate resources, like testing centers, where they are most needed.

Low Cost, Fast Testing. The random samples are collected at regular intervals and shipped to a central testing location at the Berkeley Water Center. There, the COVID-WEB team uses a technique that rapidly stabilizes and concentrates any viral RNA present in a sample so it can be measured in the lab. The technique uses table salt, ethanol, and other low-cost, easily obtained materials, making it less expensive and more sustainable than techniques that rely on complex or expensive reagents.  The test is also very sensitive and very fast; turnaround is down to about three days per sample.

SMCSD Is One Of Six Agencies in Marin County Participating in the Study. Agencies in Alameda, Contra Costa, and San Francisco Counties are also participating. The Berkeley team is rapidly expanding capacity in order to give public health officials another weapon in the battle against COVID-19 in the Bay Area. Wastewater testing may also give scientists a tool for tracking virus strains as they mutate.

For More Information

Marin Independent Journal: Marin health officials use sewer water to trace virus spread

Berkeley News: UC Berkeley launches pop-up lab to monitor Bay Area sewage for COVID-19

Wastewater Epidemiology for the Bay Area: