Environmental researchers around the world have demonstrated a correlation between SARS-CoV-2 RNA concentrations found in wastewater and COVID-19 case reports. Since August 2020, CDPHE’s Communicable Disease branch and Water Quality Control Division have been working with Colorado wastewater utilities and local universities to monitor wastewater for SARS-CoV-2 levels in Colorado communities. The result of this work culminated in the Colorado Wastewater Surveillance Collaborative. This wastewater data is used by the State and local public health agencies (LPHAs), in conjunction with case report data, to more accurately estimate trends of disease within a community. This data also gives local public health partners an early warning system for increasing disease levels in their communities as it can identify cases prior to case report data being available. In addition, the CDPHE lab performs whole genome sequencing on all positive wastewater samples for identification of mutations indicative of variants of concern.
Participating wastewater utilities collect wastewater samples twice per week from 24-hour composite samples collected just before the wastewater enters the water treatment plant. The samples are made up of a mixture from all the homes and businesses served by that wastewater utility, making this form of COVID-19 monitoring more efficient than clinical testing. CDPHE’s wastewater program also has potential to expand to neighborhood or even building-level monitoring. We are currently partnering with the University of Denver to perform wastewater sampling at two major correctional facilities in Denver.
Wastewater data can capture cases in communities where testing is unavailable, underutilized, or from asymptomatic individuals who may not seek testing. Wastewater data has been used by local public health agencies (LPHAs) to target testing and vaccination campaigns. Tri-County Health Department utilized wastewater data in a series of social media posts in nine targeted zip codes. The wastewater data was successful in generating a higher than usual community engagement in these posts. The Wastewater Surveillance Team at CDPHE is creating reports to send to LPHAs when elevated concentrations of SARS-CoV-2 are identified.
Data from the wastewater samples are available to the public via an interactive online dashboard. Currently, CDPHE is partnering with 21 wastewater utilities with plans to expand to more in the future. Wastewater disease monitoring is a vital part of understanding trends in COVID-19. In the future, we hope to expand and monitor for other communicable diseases. To learn more about the CDPHE Wastewater Monitoring Project please visit our frequently asked question page.
➽ Kevin Andresen, MPH Wastewater Surveillance Coordinator Communicable Disease Branch
