One of the first Empires to actually have an effective drainage system in its city, and the subsequent others that it when it had conquered the locals was the Romans. They were very keen on public health have quickly realised that without it illness and disease soon followed. It was one of the reasons their legions were able to be so effective. They were fitter and heather so the disease and dysentry ridden Gauls and Celts were up against it from the start. What they could have all done with was a call from a Drainage Cleaning Company. Not that the Celts and Gauls would have bothered as they didn’t have them.
The Romans used a system of lead and clay pipes, combined with a stone channel or two to move water from rivers, streams and springs. They were able to direct them into Villas, if there was a local source like the one at Chedworth, but for major towns and cities this required a bit more engineering and also the use of an aqueduct or two.
This town and city toilets were therefore communal affairs where anyone could pop in and spend a sestertius (a Roman version of the penny) or make a larger deposit if they felt the need. Rows of long holes, with a warmer wooden bench with further holes on top ,was ready for several members of the town to use. It was actually a very good way of meeting people and doing commercial business or having a catch up. The river below, which was gravity fed, whisked the waste away.