We have several local cities and towns monitoring sewage for Covid infection levels. It is interesting to note that sewage can be monitored for Covid variant type.
Scientists Find Traces of Omicron in Sewage From Sacramento and Merced
https://www.kqed.org/news/11898161/...-omicron-in-sewage-from-sacramento-and-merced
Scientists Find Traces of Omicron in Sewage From Sacramento and Merced
https://www.kqed.org/news/11898161/...-omicron-in-sewage-from-sacramento-and-merced