Since the time of Connor and Brigid, outhouses have been built over relatively small cesspits, for purposes of defecation and urination. Over time, worms, insects, and microorganisms may help decompose the waste, which eventually becomes part of the soil. However, it should also be noted that after the use of outhouses, it is common to throw ash, sawdust, or grass clippings into the pit, to help cover the odor as well as aid in decomposition.
As the population of The Land grew, people began digging large, deep underground structures called sewers, for the collection of water and biological waste products. (Eventually it became common practice for sewers to be lined with stone or brick.) Outhouses would then be built over sewers rather than cesspits, though the decomposition process remained largely the same. When paved roads eventually began to be built within villages, they would include storm drains for rain water to also enter the sewers. The depositing of waste via both outhouses and storm drains was almost exclusively dependent upon gravity. While solid waste collects and undergoes decomposition in sewers, liquid waste may separate and drain into natural bodies of water, where it undergoes further decomposition by microorganisms. These bodies of water are generally separate from larger bodies such as rivers, seas, or oceans. They may include lakes, ponds, or marshes, which are generally not used as sources of water for drinking or washing, though in larger bodies of water where the dilution levels are high (so that the ratio of liquid waste to natural water is negligible) it may be safe for activities such as swimming or fishing. Such bodies may also empty into streams or rivers, by which point any harmful contaminants from waste material will have been eliminated. These bodies of water may also be used for crop irrigation, usually with the use of aqueducts.
In the late 880s, an engineer named Lyle of Monab developed a system for indoor plumbing, and other engineers designed treatment facilities to complement the natural purification of waste from sewers, thus reducing the time it took and providing an acceptable way of reusing waste in the plumbing system, which effectively reduced the consumption of water from sources such as rivers.