“Professor and microbiologists Gertjan Medema worked on the study in Amersfoort, in the Netherlands and said tests from one sewage plant could potentially represent one million people.”

 

https://www.dailymail.co.uk/news/article-8216485/Poo-testing-help-traces-coronavirus-days-people-symptoms.html

Excellent if it works. I've heard of similar tracking for drugs, some parts of cities had more traces of substances in the waste waters.

 

The theory is solid, ingested SARS-CoV-2 would exit through the exhaust pipe and end up in the sewage. The question is, how would they be able to detect it, RT-PCR or CRISPR on random samples? Seems a bit far fetched.