NYC has a combined sewer system [0] [1] that overflows when it rains more than .... ~1/10 of an inch per hour (iirc). The fecal-> aerosol transmission route is certainly very important: https://news.ycombinator.com/item?id=27156256

"Who do you share a bathroom with" is very important for tracking transmission. In NYC, everyone shares a bathroom.

[0] https://www1.nyc.gov/site/dep/water/combined-sewer-overflows...

[1] https://www.riverkeeper.org/campaigns/stop-polluters/sewage-...