Posted by IlliniRunner on November 8, 2023, 16:32:57, in reply to "This must be the case because all of the drain pipes in my home meet in one large pipe..."
Link: https://sfpuc.org/about-us/our-systems/sewer-system#:~:text=San%20Francisco%20is%20the%20only,about%20our%20combined%20sewer%20system.