Nightsoil Collector

TW: this article discusses the disposal of bodily waste; those who prefer not to think on such topics may wish to avoid. In most of the world, a Nightsoil Collector is just that - someone with the unpleasant task of ensuring a city's worth of bodily waste is transported out of the city. In Caelester, this task has been transformed by a number of advancements in sanitation. Ancient aqueducts build by the Asurian Empire have been restored and improved upon, carrying clean water to a number of towers around the city built to contain a stockpile. From there, it enters a network of underground pipes and is distributed to buildings throughout the city. This enables the use of a contained sewer system that conducts waste through a separate network of pipes for disposal. The Nightsoil Collector's Guild operates all of these systems, and the importance of these systems is why they are among the handful of guilds not outlawed by the Steward.
While this system was heavily damaged by the earthquake 8 years ago, funding for its repair has been generously provided by the Steward (but only after the Guildmaster of the Nightsoil Collectors gave an extremely precise description of what would happen without such repairs). By now the network of tunnels that contains the water distribution and sewage collection systems has been properly shored up and leaks have been repaired. The slow process of proper reconstruction is still underway, occupying many of the Nightsoil Collectors time.
In the very depths of the sewage collection network lies the source of all this extravagance. Deep within ancient ruins below the city lies a field of intense necrotic energy that causes anything within it to decay at an incredible rate. On one side of this field, sewage is poured in, and on the other, a flammable liquid called Naphtha flows out. The guild processes this this substance to create lamp oil and tar, two products that can be sold for a substantial price.