2-4 days is actually a long time.
That entire branch of sewer is contaminated now for those patients.
Do any animals live in that sewer that might be able to be infected with coronavirus?
Do some cities pipe that stuff straight to a holding pond? Is the waste water ‘aerosolized’ at any point deliberately or inadvertently (falling down into a tank or something similar?)
What about cities with aging infrascture that have sewer leaks all the time? And the workers who have to clean that up?
Nightmare situation if true.
There’s a lot of other stuff in wastewater to worry about more (in wastewater) ...
Somewhat related (long read):
https://www.karger.com/Article/FullText/484899
Among many other things, viruses don’t like sunlight.
I don’t even want to know what lives in Chinese sewers. Calif inherited their wharf rats and they’re nasty critters. Makes lab rats look like cuddly mice. (and my vote is on rats as the unknown vector - those open market stalls are just too tempting for mr. wharf rat who craps and urinates where he eats and on what he eats).
Here, probably rats, possums, mice, snakes, alligators, nutria, roaches, mosquitoes, flies, bugs, lizards, although CV is supposed to prefer mammals. There is aeration of treatment ponds, either mechanical or static or both. Most I’ve ever seen are open and occasionally used by ducks and other birds until the fowl realize there’s no fish to be had.
But not to worry - China makes all the vaccines and viricides and...wait... uh oh
Then there are the variables for private systems. How close is the drinking water well to the neighbors’ septic system. Is there a different water source for lawn and garden watering. How deep is the well and where does that water come from.
What about the gray water running out onto the lawn or garden? Will any food being garden grown become contaminated. Of course, germy hands picking it and tending a garden would contaminate the food. How germy is the dishwashing and clothes washing water?