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<small{|style="float: left;"|{{Language-title />box|english_link=Double_Ventilated_Improved_Pit|french_link=Latrine_améliorée_à_double_fosses_ventilées|spanish_link=Pozos_Doble_Mejorado_Ventilado|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}}<!-- table at top of page with logo, picture, Application level, Management level, and input-output tables -->|}

Input1=Excreta|Input2=Faeces |Input3=Anal cleansing waterCleansing Water| Input4= Dry Cleansing Materials |Input5=|Output1=Compost - EcoHumusPit Humus| Output2= | Output3= | Output4= | Output5=|english_link=Double_Ventilated_Improved_Pit|french_link=Latrine_améliorée_à_double_fosses_ventilées|spanish_link=Pozos_Doble_Mejorado_Ventilado

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

'''The Double VIP (S.4) has almost the same design as the [[Single Ventilated Improved Pit|Single VIP]] (S.3) with the added advantage of a second pit that allows the technology to be used continuously and allows for safer and easier emptying.'''

'''Design Considerations:''' The superstructure may either extend over both holes or it may be designed to move from one pit to the other. In either case, the pit that is not being filled should be fully covered and sealed to prevent water, garbage and animals (and/, or people) from falling into the pit. The ventilation of the two pits can be accomplished using one ventilation pipe moved back and forth between the pits , or each pit can be equipped with its own dedicated pipe. The two pits in the Double double VIP are continually used and should be well lined and supported to ensure longevity.

<br>{{procontable | pro=- Longer life than Single VIP (indefinite if maintained). <br> - Excavation of humus is easier than faecal sludge. <br> - Significant reduction in pathogens <br> - Potential for use of stored faecal material as soil conditioner. <br> - Flies and odours are significantly reduced (compared to non-ventilated pits). <br> - Can be built and repaired with locally available materials <br> - Does not require a constant source of water. <br> - Suitable for all types of user (sitters, squatters, washers and wipers). <br> - Can be built and repaired with locally available materials <br> - Can be used immediately after construction. <br> - Small land area required. | con= - Low/moderate reduction in pathogens. Manual removal of humus is required<br> - Possible contamination of groundwater<br> - Higher capital cost than Single VIP; reduced operating costs if self-emptied.

===AdequacyAppropriateness=== The Double VIP is more appropriate than the [[Single Ventilated Improved Pit|Single VIP]] for denser, peri-urban areas. The After the resting time, the soil-like material is manually emptied (it is dug out, not pumped out), so vacuum truck access to the pits is not necessary. The users can remove the pit material after a sufficient resting time of one or more years even though the treatment processes in the pit are not complete and the material is not entirely hygienic. The Double double VIP technology will only work properly if the two pits are used sequentially and not concurrently. Therefore, an adequate cover for the out of service pit is required. Double VIPs are especially appropriate when water is scarce and where there is a low groundwater table. They should be located in an area with a good breezeto allow for proper ventilation. They are not suited for rocky or compacted soils (that are difficult to dig) or for areas that flood frequently.

===Operation & Maintenance=== 

<br>{|style="border: 2px solid #e0e0e0; width: 7040%; text-align: justify; background-color: #f5f5f5e9f5fd;" cellpadding="2"<!--rsr logo here-->|- style="vertical-align: top" |[[Image:rsr 474akvorsr logo_lite.jpgpng|thumbcenter|none|200px|<font size="2"><center>Project 474</center></font>60px|link=http://www.akvo.org/products/rsr/project/474/]]|'''Akvo RSR Project:''' [http://www.akvo.org/rsr/<!--project/474/ Health & Sanitation project]SLOPB aims to improve the health of women and children in the Barisal Division. The project area is among the poorest in Bangladesh, access to health facilities and sanitation is very low. The government is not very eager to improve its performance in the project area. This programme has an integrated approach: at the preventive side, attention will be paid both to WASH (both hardware as well as software) and to health (awareness raising, education, referral systems).blocks here-->|}  {|- style="width: 70%; textvertical-align: justify; background-color: #f5f5f5;bottom" |[[Image:rsr project 360.jpg|thumb|nonecenter|200px140px|<font size="2"><center>[http://rsr.akvo.org/project/360/ RSR Project 360]<br>WASH Facilities at Kajiado Schools</center></font>|link=http://wwwrsr.akvo.org/rsr/project/360/]]|'''Akvo RSR Project[[Image:''' project 474.jpg |thumb|center|140px|<font size="2"><center>[http://wwwrsr.akvo.org/rsrproject/474/RSR Project 474]<br>Health & Sanitation project</center></font>|link=http:/360/ WASH Facilities at Kajiado Schools]The Maasai communities generally do not prioritize hand washing or digging pit latrinesrsr. Natural water sources are unprotected and shared with animals, posing serious health risksakvo. Many schools in the area do not have safe and adequate water and sanitation facilities. NOSIM aims to increase water availability for school children, to reduce incidencesorg/project/474/impact of WASH-related disease through construction of rainwater harvesting and sanitation facilities, plus awareness raising through WASH Clubs.]]

* Mara DDFranceys, R., Pickford, J. and Reed, R. (19841992). The Design of Ventilated Improved Pit Latrines (UNDP Interreg[https://www.susana. Project INTorg/81_resources/047)documents/default/2-1651-who-a-guide-to-the-development-of-on-site-sanitation.pdf A Guide to the Development of on-Site Sanitation]. The World Bank+ UNDPWHO, WashingtonGeneva, CH. (A good reference for detailed Double Pit VIP design information.)

* MaraGraham, DDJ. P. and Polizzotto, M. L. (19962013). Low-Cost Urban Sanitation[https://pubmed.ncbi. Wileynlm.nih.gov/23518813/ Pit Latrines and Their Impacts on Groundwater Quality: A Systematic Review]. Environmental Health Perspectives, ChichesterNational Institute of Environmental Health Sciences, UKResearch Triangle Park, US. (General description of VIPs with a focus on the ventilation system.) General Information:

* FranceysMara, RD., Pickford, J. and Reed, RD. (19921984). A guide to the development [https://www.pseau.org/outils/ouvrages/world_bank_the_design_of_ventilated_lmproved_pit_latrines_1984.pdf The Design of on-site sanitationVentilated Improved Pit Latrines]. WHOUNDP Interregional Project INT/81/047, The World Bank and UNDP, GenevaWashington, D.C., US. (A good reference for detailed double VIP design information)

* LewisMara, JWD., et alD. (19821996). The Risk of Groundwater Pollution by onLow-site Cost Urban Sanitation in Developing Countries. International Reference Centre for Waste DisposalWiley, DübendorfChichester, SwitzerlandUK. (Detailed study regarding Book; General description of VIPs with a focus on the transport and die-off of microorganisms and implications for locating technologies.ventilation system)

* The World Bank Morgan, P. R. (19862009). Information and Training for Low[http://www.ecosanres.org/pdf_files/EcologicalToilets-PeterMorgan-Cost Water Supply Mar2009.pdf Ecological Toilets. Start Simple and Sanitation (UNDP Project INT/82/002)Upgrade from Arborloo to VIP]. The World BankStockholm Environment Institute, Stockholm, WashingtonSE.