How can health officials determine the amount of COVID-19 in a community? Health officials use many ways to determine the impact of COVID-19, such as the number of cases, number of hospitalizations, and wastewater data!

How does wastewater testing work?

  • When you have COVID-19, you shed the virus in your feces which goes down your drain and into the community sewer system.
  • Samples of wastewater are collected at water treatment plants and tested for the amount of COVID-19 virus present before the water is cleaned.
  • Health officials track the amount of virus over time to see if it is going up or down at the community level.

Why wastewater?

  • We know some people do not have symptoms when they have COVID-19 and with the popularity of at-home tests, many COVID-19 cases may not be reported.
  • Whether or not you know you have symptoms, COVID-19 virus can be detected in feces and other bodily waste. Therefore, wastewater testing helps health officials determine the amount of COVID-19 in the community.
  • Wastewater testing complements other COVID-19 data such as the number of cases and hospitalizations. Wastewater testing cannot determine the actual number of COVID-19 cases in a community.

Where is wastewater tested in the United States?

  • Lots of places! The colorful dots on the map below represent all of the water treatment plants that report COVID-19 virus levels to the Centers for Disease Control and Prevention (CDC).
  • As of October 10, 2023 there are a total of 1,726 wastewater sampling sites in the United States.

Map Source: Centers for Disease Control and Prevention

Is the wastewater in Medina County tested?

  • While many individuals in Medina County have personal septic systems that do not contribute waste to a public sewer system, one water treatment plant reports COVID-19 virus levels in community wastewater. The plant services about 35,000 Medina County residents.
  • The data from this treatment plant is available through the CDC’s COVID Data Tracker.

Additional resources

1 – Wastewater Surveillance Testing Methods | National Wastewater Surveillance System | CDC

2 – CDC COVID Data Tracker: Wastewater Surveillance

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