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Wastewater (sewage) can be tested to detect traces of infectious diseases circulating in a community, even if people don’t have symptoms. You can use these data as an early warning that levels of infections may be increasing or decreasing in your community.

Wastewater COVID-19 National and Regional Trends

COVID-19 Wastewater Monitoring in the U.S.

Region with the highest wastewater viral activity level for COVID-19:
From DB

This chart shows national and regional trends of wastewater viral activity levels of SARS-COV-2 (the virus that causes COVID-19).

Wastewater monitoring can detect viruses spreading from one person to another within a community earlier than clinical testing and before people who are sick go to their doctor or hospital. It can also detect infections without symptoms. If you see increased wastewater viral activity levels, it might indicate that there is a higher risk of infection. See how to protect yourself from respiratory viruses.

About the Wastewater Viral Activity Level: The wastewater viral activity level indicates whether the amount of virus in the wastewater is minimal, low, moderate, high, or very high. The wastewater viral activity levels may indicate the risk of infection in an area. The wastewater viral activity levels are categorized as follows:

  • Up to 1.5 – Minimal
  • Greater than 1.5 and up to 3 – Low
  • Greater than 3 and up to 4.5 – Moderate
  • Greater than 4.5 and up to 8 – High
  • Greater than 8 – Very High

National and regional data represent the median values across all wastewater treatment plants in the respective area. To learn more on how the wastewater viral activity level is calculated, see Data Methods.

Regions: States and territories are grouped into the following U.S Census Bureau regions:

  • West: Alaska, Arizona, California, Colorado, Guam, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, Wyoming (N=14)
  • Midwest: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, Wisconsin (N=12)
  • Northeast: Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Puerto Rico, Rhode Island, Vermont (N=10)
  • South: Arkansas, Alabama, Delaware, District of Columbia, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, West Virginia (N=17)