Adry toilet(ornon-flush toilet, no flush toiletortoilet without a flush) is atoiletwhich, unlike aflush toilet,does not use flush water.[1]Dry toilets do not use water to move excreta along or block odors.[2]They do not producesewage,and are not connected to asewer systemorseptic tank.Instead,excretafalls through a drop hole.[1]
![](https://upload.wikimedia.org/wikipedia/commons/thumb/6/62/Schematic_of_the_Dry_Toilet.png/330px-Schematic_of_the_Dry_Toilet.png)
A variety of dry toilets exist, ranging from simplebucket toiletsto specializedincineratingandfreezingtoilets.
Types
editTypes of dry toilet, listed in approximate order from simplest to most complex, include:
- Bucket toilet– The most basic kind of toilet. May have a toilet seat, with or without a lid. May be accompanied by material (e.g. wood ash, sawdust, or quick lime) to cover excreta after use.
- Pit latrine– excluding pour-flush versions with water seal
- Urine-diverting dry toilet– urine and fecescollected separately
- Composting toilet
- Container-based toilet– excreta is collected in sealable, removable containers (also called cartridges) which are later transported to waste treatment facilities
- Packaging toilet – packages feces separately after each use
- Incinerating toiletsandfreezing toilets– More complex technology than most dry toilets. Require electricity (or other suitable energy source) to function.
Other types of dry toilets are under development at universities, for example since 2012 funded by theBill and Melinda Gates Foundation.Such toilets are meant to operateoff-the-gridwithout connections to water, sewer, or electrical lines.[2]
Terminology
editOne important source states that the termdry toiletshould only refer to the user interface and not the subsequent storage and treatment steps.[1]However, in theWASHsector, the termdry toiletis used differently by different people. It often includes also the storage and treatment steps. For example, it is common that the termdry toiletis used to refer specifically to a urine-diverting dry toilet or a composting toilet.[3][4]
People also use the term to refer to a pit latrine without a water seal even though the pit of a pit latrine is not usually dry. The pit can become very wet because urine mixes with feces in the pit anddrainagemight be limited.[citation needed]Additionally,groundwaterorsurface watercan also get into the pit in the event of heavy rains or flooding. Sometimes households even discardgreywater(from showering) into the same pit.[citation needed]
Some publications use the termdry sanitationto denote a system that includes dry toilets (in particular urine-diverting dry toilets) connected to a system to manage the excreta.[3][4]Alternative terms arenon sewer-based sanitationornon-sewered sanitation(see alsofecal sludge management).
The termouthouserefers to a small structure, separate from a main building, which covers a pit toilet or a dry toilet. Although it strictly refers only to the structure above the toilet, it is often used to denote the entire toilet structure, i.e. including the hole in the ground in the case of a pit latrine.
Gallery
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Aurine-diverting dry toiletin South Africa.
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Composting toiletat Activism Festival 2010 in the mountains outside Jerusalem.
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Acomposting toiletschematic (Clivus Multrum).
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AnArborloofor later planting trees.
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Acontainer-based toiletorbucket toilet,another type of dry toilet.
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Schematic of a simplepit latrinewith a squatting pan and shelter.[5]
Uses
editDry toilets (in particular simple pit latrines) are used in developing countries in situations in which flush toilets connected to septic tanks or sewer systems are not possible or not desired, for example due to costs. Sewerage infrastructure costs can be very high in instances of unfavorable terrain or sprawling settlement patterns.
Dry toilets (in particular composting toilets) are also used in rural areas of developed countries, e.g. many Scandinavian countries (Sweden, Finland, Norway) for summer houses and in national parks.
Advantages
editDry toilets can be a suitable alternative towater-flushed toiletswhen water for flushing is of short supply.[6]Another reason for using dry toilets can be that the infrastructure to deal with the wastewater produced from flush toilets is too expensive to construct.[6]
Dry toilets are used for three main reasons instead of flush toilets:[4]
- To save water – when there is eitherwater scarcity,water is costly (such as inaridorsemi-aridclimates) or because the user wants to save water for environmental reasons. However, water savings from dry toilets might be insignificant compared to other possible water savings in households or within agricultural practices.
- To preventpollution of surface waterorgroundwater– dry toilets do not mix excreta with water and do not pollute groundwater (except for pit latrines which may pollute groundwater); they do not contribute toeutrophicationin surface water bodies.
- To enable safereuse of excreta,after the collected excreta orfecal sludgehas undergone further treatment for example by drying orcomposting.
Dry toilets and excreta management without sewers can offer more flexibility in construction than flush toilet and sewer-based systems.[3]It can be a suitable system in areas that face growingwater scarcitydue toclimate changesuch asLima,Peru.[3]
Challenges
editDry toilets do not have a water seal, thusodorsmay be a problem.[1]This is often the case for pit latrines, UDDTs or composting toilets if they are not designed well or not used properly.
Dry toilets that are connected to a pit (such as pit latrines) tend to make it very difficult to empty the pit in a safe manner when they are full (seefecal sludge management). On the other hand, dry toilets that are not connected to a pit (e.g. container-based toilets, UDDTs and composting toilets) usually have a safe method for emptying built into them as they are designed to be emptied on a regular and quite frequent basis (within days, weeks or months).
History
editThe history of dry toilets is essentially the same as the history oftoiletsin general (until the advent offlush toilets) as well as the history ofecological sanitationsystems with regards toreuse of excretain agriculture.
Dry earth closets
editDry earth closets were invented by English clergymanHenry Moule,who dedicated his life to improvingpublic sanitationafter witnessingthe cholera epidemics of 1849 and 1854.Impressed by theinsalubrityof the houses, especially during theGreat Stinkin the summer of 1858, he invented what he called the 'dry earth system'.[7]
In partnership with James Bannehr, he patented his device (No. 1316, dated 28 May 1860). Among his works bearing on the subject wereThe Advantages of the Dry Earth System(1868),The Impossibility overcome: or the Inoffensive, Safe, and Economical Disposal of the Refuse of Towns and Villages (1870), TheDry Earth System(1871),Town Refuse, the Remedy for Local Taxation(1872), andNational Health and Wealth promoted by the general adoption of the Dry Earth System(1873). His system was adopted in private houses, in rural districts, in military camps, in many hospitals, and extensively in theBritish Raj.[7]Ultimately, however, it failed to gain public support as attention turned to the water-flushedtoiletconnected to a sewer system.
In Germany, a dry toilet with a peat dispenser was marketed until after the Second World War. It was called "Metroclo" and was manufactured by Gefinal, Berlin.
Britain
editIn Britain, use of dry toilets continued in some areas, often urban areas, through to the 1940s. It seems that these were often emptied directly onto their gardens, where the excreta was used as fertilizer.[8]Sewer systems did not come to some rural areas in Britain until the 1950s or even after that.
Australia
editBrisbane,Australia was largely unsewered until the early 1970s, with many suburbs having a dry toilet (called adunny) behind each house.[9][10][11]AcademicGeorge Seddonclaimed that "the typical Australian back yard in the cities and country towns" had, throughout the first half of the twentieth century, "a dunny against the back fence, so that the pan could be collected from the dunny lane through a trap-door".[12]
References
edit- ^abcdeTilley, E.; Ulrich, L.; Lüthi, C.; Reymond, Ph.; Zurbrügg, C. (2014).Compendium of Sanitation Systems and Technologies(2nd Revised ed.). Swiss Federal Institute of Aquatic Science and Technology (Eawag), Duebendorf, Switzerland.ISBN978-3906484570.
- ^abShaw, R. (2014).A Collection of Contemporary Toilet Designs.EOOS and WEDC, Loughborough University, UK. p. 40.ISBN978-1843801559.
- ^abcdPlatzer, C., Hoffmann, H., Ticona, E. (2008).Alternatives to waterborne sanitation – a comparative study – limits and potentials.IRC Symposium: Sanitation for the urban poor – partnerships and governance, Delft, The Netherlands
- ^abcFlores, A. (2010).Towards sustainable sanitation: evaluating the sustainability of resource-oriented sanitation.PhD Thesis, University of Cambridge, UK
- ^WEDC.Latrine slabs: an engineer's guide, WEDC Guide 005(PDF).Water, Engineering and Development Centre The John Pickford Building School of Civil and Building Engineering Loughborough University. p. 22.ISBN978-1843801436.Archived(PDF)from the original on 4 March 2016.Retrieved22 May2016.
- ^abRieck, C., von Münch, E., Hoffmann, H. (2012). Technology review of urine-diverting dry toilets (UDDTs) – Overview on design, management, maintenance and costs. Deutsche Gesellschaft fuer Internationale Zusammenarbeit (GIZ) GmbH, Eschborn,Germany
- ^ab"Fordington, Biography, Rev Henry Moule, 1801–1880".freepages.genealogy.rootsweb.ancestry.Archived fromthe originalon 2011-05-09.Retrieved2017-03-29.
- ^Lewis, Dulcie (1996).Kent privies.Newbury: Countryside Books. p. 128.ISBN978-1853064197.
- ^"Observations « Carry the Bags".
- ^Essays in the Political Economy of Australian Capitalism.Vol. 2. Australia and New Zealand Book Company. 1978. p. 115.ISBN978-0855520564.Retrieved5 July2017.
- ^Smith, Graham (2011).Shadows of War on the Brisbane Line.Boolarong Press. pp. 183–184. Archived fromthe originalon 2017-03-11.Retrieved5 July2017.
- ^Craven, Ian; George Seddon (1994). "The Australian Back Yard".Australian Popular Culture.