Editing Composting toilet (section)

== Uses of compost ==
[[File:Kiel-Hassee Erde mit Schubkarre (5708339858).jpg|thumb|Finished compost from a composting toilet ready for application as soil improvement in Kiel-Hassee, Germany]]
{{Main article|Uses of compost|Reuse of excreta}}
The material from composting toilets is a [[humus]]-like material, which can be suitable as a [[soil amendment]] for agriculture. Compost from residential composting toilets can be used in domestic gardens, and this is the main such use.

Enriching soil with compost adds substantial nitrogen, phosphorus, potassium, carbon and calcium. In this regard compost is equivalent to many [[fertilizers]] and [[manures]] purchased in garden stores. Compost from composting toilets has a higher nutrient availability than the dried feces that result from a [[urine-diverting dry toilet]].<ref name=":1" />

Urine is typically present, although some is lost via leaching and evaporation. Urine can contain up to 90 percent of the residual [[nitrogen]], up to 50 percent of the [[phosphorus]], and up to 70 percent of the [[potassium]].<ref>[http://www2.gtz.de/Dokumente/oe44/ecosan/en-fighting-urine-blindness-1998.pdf J.O. Drangert, Urine separation systems] {{webarchive|url=https://web.archive.org/web/20141222023233/http://www2.gtz.de/Dokumente/oe44/ecosan/en-fighting-urine-blindness-1998.pdf |date=2014-12-22 }}</ref>

[[Compost]] derived from these toilets has in principle the same uses as compost derived from other organic waste products, such as [[sewage sludge]] or municipal organic waste. However, users of waste-derived compost must consider the risk of pathogens.

===Pharmaceutical residues===
Waste-derived compost may contain [[Prescription drug|prescription]] [[pharmaceuticals]]. Such residues are also present in conventional [[sewage treatment]] effluent. This could [[groundwater pollution|contaminate groundwater]]. Among the medications that have been found in groundwater in recent years are [[antibiotic]]s, [[antidepressant]]s, [[blood thinner]]s, [[ACE inhibitor]]s, [[calcium-channel blocker]]s, [[digoxin]], [[estrogen]], [[progesterone]], [[testosterone (medication)|testosterone]], [[Ibuprofen]], [[caffeine]], [[carbamazepine]], [[fibrate]]s and [[cholesterol]]-reducing medications.<ref>{{cite book |title= Drugs in the Water |year= 2011|publisher= Harvard Health Letter |url=http://www.health.harvard.edu/newsletters/Harvard_Health_Letter/2011/June/drugs-in-the-water}}</ref> Between 30% and 95% of pharmaceuticals medications are excreted by the human body. Medications that are [[lipophilic]] (dissolved in fats) are more likely to reach groundwater by leaching from fecal wastes. Sewage treatment plants remove an average of 60% of these medications.<ref>Encyclopedia of Quantitative Risk Analysis and Assessment, Volume 1, edited by Edward L. Melnick, Brian S. Veritt, 2008</ref> The percentage of medications degraded during composting of waste has not yet been reported.