Boy, in a place like this the waste of so many citizens and their livestock can add up faster than… well… a pile of crap!
Let us examine how Metamor Keep deals with their waste.
Within the confines of the Keep itself this little problem is taken care of by Kyia's magic and the internal water managment system that flows throughout the keep. Eventually all of the accrued waste is disposed of in a subterrainian river fed by glacial melt and some overflow from the Metamor River. This underground river carries it some distance under the mountains where it ends up in a lake. Beneath this lake is another river which finds its way to a volcanic system that serves to reduce the waste water and its contents to so much vapor that works its way upward through ancillary caverns and escapes in hundreds of locations throughout the Dragon Mountains.
But the Keeptowne and Euper do not have Kyia's handy magical managment system so they have come up with an entire new approach to waste removal. Perhaps not new in the overall view of the world setting, but it is nonetheless effective.
There are latrines pretty much everywhere, some of them within buildings but for the most part they are outside in alleys or other somewhat out-of-the-way locations that are easily accessed. These latrines are all at ground-level and can be as small as a single occupant outhouse to a large public latrine that can service a dozen or more at once. They are all essentially just open-drop constructions with both 'seats' to use and simple holes in the floor. Depending on the particular morph aspect of the user either of these are servicable.
It is a violation of the law to empty nightsoil into the streets in any city of the Northern Midlands. All privy and chamberpot contents are expected to be taken to a latrine for disposal.
Private latrines may just be deep holes in the ground in a person's yard (which must be spaced a fair distance from any well), but public latrines are all stationed above a sewage system that runs underneath the city, carrying the raw sewage from the latrines out to one of a dozen large plots of land south of the Keep & Euper (as the prevailing wind typically comes from the north) and emptied into compost heaps. Over the next few months the waste is composted.
One of the punishments meted out by the Wardens is for lawbreakers to work on one of these compost farms.
The resulting compost is free to anyone who wants it. This is generally gardeners and farmers around the area of the Keep resulting in unusually high crop yields within a day or two of Metamor Keep.