[cblades]

You don't need live viruses, just their RNA.

[kardos]

... so do we know how fast the RNA degrades in sewer conditions?

[epmaybe]

very, very fast.

[marcosdumay]

Slowly enough to not matter. Unless something is degrading it, RNA can last years.

[ddrt]

I’m pretty sure ribonucleases are found everywhere (even in sewage) so if enough are present it would break down all RNA fast. RNases come from skin and dust, for example.

[xkcd-sucks]

lol no, rna degrades if you so much as look at it. dna is quite a bit more stable.

https://www.bioline.com/rna-hints-and-tips/