Wastewater surveillance is a tool that was originally developed in the 1940s to monitor sewage for polio and other various viral pathogens. Today, it's helping us to monitor our region for the prevalence of the COVID-19 virus. You can learn more about wastewater testing programs by visiting the CDC's National Wastewater Surveillance Systems (NWSS) page.
We've teamed up with wastewater epidemiologists, Biobot Analytics, to process samples from several locations in Mariposa and Yosemite on a regular basis. Reports will be updated below as they become available.
If you have any questions about our program, please call the CoVID-19 information line: 209-259-1332
Wastewater surveillance in Mariposa and Yosemite will be put on hold during the winter months when they are less people visiting the county. We expect to resume the testing in Spring 2021.
Data last updated: 4/21/2021
* please note that this data does not include a sample taken from the El Portal site that was recorded on August 10th at 13,257,797 genome copies per liter of sewage. This does not include a sample taken from the Wawona site that was recoded on November 30th at 1,440,103.