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<!{|style="float: left;"|{{Language-- table at top of page with logo, picture, Application level, Management level, and input-output tables -->box|english_link=Dehydration_Vaults|french_link=Chambre_de_déshydratation|spanish_link=Camaras_de_Deshidratacion|hindi_link=coming soon|malayalam_link=coming soon|tamil_link=coming soon | korean_link=coming soon | chinese_link=Coming soon | indonesian_link=Coming soon | japanese_link=Coming soon}}|}

Input1=Faeces |Input2=Dry Cleansing Materials| Organics |Input3=|Input4=|Input5=|

|[[Image:Dehydration_vaults.png |right|300px500px]]

[[Image:Icon_dehydration_vault.png |right|95px]]'''Dehydration vaults are used to collect, store and dry (dehydrate) faeces. Faeces will only dehydrate when the vaults are watertight to prevent external moisture from entering and when urine and anal cleansing water are diverted away from the vaults.''' [[Image:Vaults_and_chambers.PNG|thumb|right|150px|[[Vaults and chambers |Dy]], in South Africa(for credits, click the picture)80px]]

[[Image:'''Dehydrationvaults are used to collect, store and dry (dehydrate) faeces.PNG‎|thumb|right|150px|[[Dehydration |Dehydration]]Faeces will only dehydrate when the vaults are well ventilated, in Ecuador (for creditswatertight to prevent external moisture from entering, click and when urine and anal cleansing water are diverted away from the picture)]]vaults.'''

When urine is separated from faeces, the faeces dry quickly<br>[[Image:Vaults_and_chambers. In the absence of moisture, organisms cannot grow PNG|thumb|right|200px|[[Vaults and as suchchambers |Dy]], smells are minimized and pathogens are destroyed. Vaults used for drying faeces in the absence of urine have various local names. One of the most common names South Africa(for this technology is credits, click the Vietnamese Double Vaults.picture)]]

Excreta may When faeces are not mixed with urine and other liquids, they dry inside quickly. In the vault as a result absence of sun radiationmoisture, natural evaporation organisms cannot grow, pathogens are destroyed and ventilationsmells minimized. Absorbents such as limeThe use of two alternating vaults allows the faeces to dehydrate in one vault while the other vault fills. When one vault is full, the [[Urine Diverting Dry Toilet | Urine-Diverting Dry Toilet]] (UDDT, ash or dry soil should be added U.2) is moved to the chamber after each defecation second vault. While the second vault fills up, the faeces in the first vault dry and decrease in order to absorb moisturevolume. When the second vault is full, making the pile less compactfirst one is emptied and put back into service. The product from To prevent flies, minimize odours and encourage drying, a dehydration process is a kind small amount of mulchash, rich in humuslime, carbon, fibrous material, phosphorous and potassium. It dry soil or sawdust should be stored, sun-dried or composted in order used to kill off all pathogenscover faeces after each use.

===Design Considerations=== Dehydration vaults can be constructed indoors or with a separate superstructure. A family of 6 will produce 500L of faeces in approximately six months. For design purposes it vent pipe is recommended required to assume that one person will require almost 100L of faeces storage space every six monthsremove humidity from the vaults and control flies and odours. The vaults chambers should be slightly oversized to account airtight for airflow, visitors and the non-even distribution proper functioning of faeces in the chamberventilation. Each vault is sized They should be made of sealed brickwork or concrete to accommodate sixmonths ensure that surface runoff cannot enter. The WHO recommends a minimum storage time of faeces accumulation which in turn6 months if ash or lime are used as cover material (alkaline treatment), results in a six month drying time in otherwise the out-of-service vaultstorage should be for at least 1 year for warm climates (>20 °C average) and for 1.5 to 2 years for colder climates.

Two alternating vaults allow the In case of alkaline treatment, each vault is sized to accommodate at least 6 months of faeces to dehydrate accumulation. This results in one vault while the other vault fills. When one vault is full it is sealed with a lid 6 month storage and dehydration time in the UDDT (U2) is moved to the second out-of-service vault. While the second The vault fills updimensions should account for cover material, airflow, the uneven distribution of faeces in the first vault slowly dry , and decrease in volume. When the second vault is full, it is sealed, the dry material from the first vault is removed possibly visitors and the first vault is then put back into service. The vaults must be watertight to keep the faeces as dry as possiblecleansing materials. Chambers should It can be constructed assumed that one person will require around 50 L of sealed block or formed concrete to ensure that rainwater, surface run-off, greywater and urine are prevented from entering the vaultsstorage volume every 6 months. Urine can be collected in a bucket and discharge A minimum chamber height of 60 to the ground (garden) or stored in a tank 80 cm is recommended for future transport easy emptying and use. A vent is required access to help keep the vaults dry and control flies and odoursurine pipes.

- Significant reduction in pathogens<br>- Can be built and repaired with locally available materials. <br> - Because double pits are used alternately, their life is virtually unlimited. <br> - Potential for use of dried faeces as soil conditioner<br>- Good in rocky and/or flooded areas. <br> - Excavation of dried faeces is easier than faecal sludge. <br> - No real problems with flies or odours if used correctly(i.e. <br> - Does not require a constant source of water, kept dry). <br> - Suitable for all types of user (sitters, squatters, washers and wipers). <br> - Low (but variable) capital costs depending on materials; no or low operating costs. <br> - Small land area required. | con=- Requires education training and acceptance to be used correctly. <br> - Requires constant source of cover material, e.g. ash, sand or lime. <br> - Requires a place where urine and treated Manual removal of dried faeces can be used or discharged. <br> - Urine and faeces require manual removal. is required

==Adequacy=Appropriateness===Dehydration Vaults vaults can be installed in almost every setting , from rural to dense urban areas, because of the small land area required, the minimal odours and the ease of use. They If used in an urban context, this technology relies on a transport service for the dried faeces (and urine) since urban users normally do not have an interest and/or opportunity to use it locally. Dehydration vaults are especially appropriate for water -scarce and rocky areasor where the groundwater table is high. In They are also suitable in areas that are frequently flooded, Dehydration Vaults are appropriate because they are constructed built to be watertight. Furthermore, where there is no plot of land available, the vaults can be installed indoors, which also makes this technology applicable for colder climates (where leaving the house is less desirable). ==Health Aspects/Acceptance == Dehydration Vaults can be a clean, comfortable, and easy-to-use technology. When users are well educated and understand how the technology works they may be more willing to accept it as a viable sanitation solution. When the vaults are kept dry, there should be no problems with flies or odours. Faeces from the double vaults should be very dry and relatively safe to handle provided they were continuously covered with material and not allowed to get wet.

There ===Health Aspects/Acceptance=== Dehydration vaults can be a clean, comfortable, and easy-to-use technology. It is a low health risk for those whom have crucial, however, that the users are well trained to empty understand how the technology works and appreciate its benefits. When the vaults are kept dry, there should not be any problems with flies or change odours. After the urine containerrecommended storage time, the faeces should be very dry and relatively safe to handle, provided that they did not get wet. Faeces that have been dried for over one year also pose However, a low health riskremains. Single dehydration vaults or bins do not allow faeces to sufficiently dehydrate.

There is a risk however when using single ===Operation & Maintenance=== Just like the faeces which are dried, but not degraded in the vaults, that dry cleansing materials will not decompose in the top portion of chambers. Whenever the faeces will not material is intended to be fully dried applied onto fields without further treatment, it is recommended to separately collect and/or hygienizeddispose of the dry cleansing materials. Single vaults are not recommended (because of Occasionally, the need to handle fresh faeces) and that have accumulated beneath the toilet should, whenever possible be upgraded pushed to a double vaultthe sides of the chamber.

* Rieck, C., von Münch, E. and Hoffmann, H. (2012). [httphttps://zoomzapwww.susana.comorg/en/knowledge-hub/resources-and-publications/manualslibrary/SESdetails/download874 Technology Review of Urine-esp.php Manual del Sanitario Ecologico SecoDiverting Dry Toilets (UDDTs)].] A very comprehensive manual on dry chamber construction including detailed instruction Overview of Design, Operation, Management and material listsCosts. In SpanishDeutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, Eschborn, DE.

* GTZ Winblad, U. and Simpson-Hébert, M. (2005Eds.) (2004). [http://www.sanimapecosanres.netorg/xoops2pdf_files/uploads/gnavi/12_2Ecological_Sanitation_2004.pdf Urine diverting dry toilets programme disseminationEcological Sanitation. Revised and Enlarged Edition] (data sheet). GTZStockholm Environment Institute, GermanyStockholm, SE. General overview (A general description of Dehydration Chambers with some dimensioning various designs and materials lists.adaptations, especially Chapter 3)

* Winblad, U., and Simpson-Herbert, M. (eds.) WHO (20042006). [https://wikiwww.umnwho.eduint/water_sanitation_health/pubpublications/EWBgsuweg4/Ugandaen/SIDAGuidebookGuidelines for the Safe Use of Wastewater, Excreta and Greywater.pdf Ecological Sanitation - revised Volume 4: Excreta and enlarged editionGreywater Use in Agriculture]. SEIWorld Health Organization, Stockholm, Sweden. A general description of various designs and adaptationsGeneva, especially Chapter 3CH.

* [http://www.wecfwho.euint/index.php Women in Europe for a Common Future] (2006). [http:water_sanitation_health/publications/www.permacultuurnederland.orgguidelines-on-sanitation-and-health/permacultuurtken/urinedivert.pdf Urine diverting ToiletsWHO: Principles, Operation Guidelines on sanitation and Constructionhealth - 2018]. Photos and explanation of how to build a double vault and superstructure.

===Acknowledgements===