sys1=[[Single Pit System|1]]|
sys2=[[Waterless System with Alternating Pits|2]]|
sys3=[[Pour Flush Pit System with Twin Pitswithout Sludge Production|3]]|
sys4=[[Waterless System with Urine Diversion|4]]|
sys5=[[Blackwater Treatment Biogas System with Infiltration|5]]|
sys6=|
sys7=|
ManShared=XX|
ManPublic=|
Input1=Effluent |Input2=Greywater |Input3=Urine | Input4= Anal Cleansing Water|Input5=Stored Urine|Output1=- Stored Urine |Output2= Anal Cleansing Water | Output3= | Output4= | Output5=
|english_link=Soak_Pit
|french_link=Puisard
[[Image:Icon_soak_pit.png |right|80px]]
'''A Soak Pitsoak pit, also known as a soakaway or leach pit, is a covered, porous-walled chamber that allows water to slowly soak into the ground. Pre-settled effluent from a Collection and Storage/Treatment or (Semi-) Centralized Treatment technology is discharged to the underground chamber from where which it infiltrates into the surrounding soil.'''
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The Soak Pit can be left empty and lined with a porous material As wastewater (to provide support and prevent collapsegreywater or blackwater after primary treatment), or left unlined and filled with coarse rocks and gravel. The rocks and gravel will prevent percolates through the walls soil from collapsingthe soak pit, but will still provide adequate space for small particles are filtered out by the wastewatersoil matrix and organics are digested by microorganisms. In both casesThus, a layer of sand and fine gravel should be spread across the bottom to help disperse the flow. The soak pit should be between 1.5 and 4m deeppits are best suited for soil with good absorptive properties; clay, but never less than 1.5m above the ground water tablehard packed or rocky soil is not appropriate.
As wastewater ===Design Considerations=== The soak pit should be between 1.5 and 4 m deep, but as a rule of thumb, never less than 2 m above the groundwater table. It should be located at a safe distance from a drinking water source (preideally more than 30 m). The soak pit should be keptaway from high-treated greywater traffic areas so that the soil above and around it is not compacted. It can be left empty and lined with a porous material to provide support and prevent collapse, or blackwater) percolates through left unlined and filled with coarse rocks and gravel. The rocks and gravel will prevent the soil walls from collapsing, but will still provide adequate space for the Soak Pitwastewater. In both cases, small particles are filtered out by a layer of sand and fine gravel should be spread across the bottom to help disperse the soil matrix and organics are digested by micro-organismsflow. ThusTo allow for future access, Soak Pits are best suited a removable (preferably concrete) lid should be used to soils with good absorptive properties; clay, hard packed or rocky soils are not appropriateseal the pit until it needs to be maintained.
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{{procontable | pro=
- Can be built and repaired with locally available materials. <br> - Technique simple to apply for all users <br>- Small land area required. <br> - Low capital cost; low and operating cost. <br> - Can be built and maintained with locally available materials. <br> - Simple technique for all users. costs | con=- Pretreatment Primary treatment is required to prevent clogging, although eventual clogging is inevitable. <br> - May negatively affect soil and groundwater properties.
}}
<br>===AdequacyAppropriateness===A Soak Pit soak pit does not provide adequate treatment for raw wastewater and the pit will quickly clog quickly. A Soak Pit It should be used for discharging presettled pre-settled blackwater or greywater. Soak pits are appropriate for rural and peri-urban settlements. They depend on soil with a sufficient absorptive capacity. They are not appropriate for areas that are prone to flooding or that have high groundwater tables. ===Health Aspects/Acceptance===As long as the Soak Pit is not used for raw sewage, and as long as the previous Collection and Storage/Treatment technology is functioning well, health concerns are minimal. The technology is located underground and thus, humans and animals should have no contact with the effluent. It is important however, that the Soak Pit is located a safe distance from a drinking water source (ideally 30m). Since the Soak Pit is odourless and not visible, it should be accepted by even the most sensitive communities.
===MaintenanceHealth Aspects/Acceptance===A well-sized Soak Pit should last between 3 and 5 years without maintenance. To extend As long as the life of a Soak Pitsoak pit is not used for raw sewage, care should be taken to ensure that and as long as the effluent has been clarified previous Collection andStorage/or filtered Treatment technology is functioning well to prevent excessive build up of solids, health concerns are minimal. The Soak Pit technology is located underground and, thus, humans andanimals should be kept away from high-traffic areas so that have no contact with the soil above and around it is not compactedeffluent. When the performance of the Soak Pit deteriorates, the material inside Since the soak pit can be excavated is odourless and refilled. To allow for future accessnot visible, a removable (preferably concrete) lid it should be used to seal accepted by even the pit until it needs to be maintainedmost sensitive communities.
===Operation & Maintenance=== A well-sized soak pit should last between 3 and 5 years without maintenance. To extend the life of a soak pit, care should be taken to ensure that the effluent has been clarified and/ or filtered to prevent the excessive build-up of solids. Particles and biomass will eventually clog the pit and it will need to be cleaned or moved. When the performance of the soak pit deteriorates, the material inside the soak pit can be excavated and refilled.
===Field experiences===
===References===
* Ahrens, B. (2005). [http://cee.eng.usf.edu/peacecorps/5%20-%20Resources/Theses/Sanitation/2005Ahrens.pdf A Comparison of Wash Area and Soak Pit Construction: The Changing Nature of Urban, Rural, and Peri-Urban Linkages in Sikasso, Mali]. Peace CorpCorps, USAUS. (Detailed construction instructions):Available at: [http://www.mtu.edu/peacecorps/programs/civil/theses mtu.edu/peacecorps/programs/civil/theses] * Mara, D. D. (1996). Low-Cost Urban Sanitation. Wiley, Chichester, UK. pp. 63-65.(Dimensioning calculations)
* Mara, DD. Oxfam (19962008). [http://books.googleSeptic Tank Guidelines.com/books/about/Low_cost_urban_sanitation.html?id=WOgeAQAAIAAJ Low-Cost Urban Sanitation]Technical Brief. WileyOxfam GB, ChichesterOxford, UK. pp 63–65p. 4.:Available at: policy-practice.oxfam. Dimensioning calculationsorg.uk
* Polprasert, C. and Rajput, VSV. S. (1982). [http://docs.watsan.net/Scanned_PDF_Files/Class_Code_3_Sanitation/323.2-82SE-884.pdf Environmental Sanitation Reviews: . Septic Tank and Septic Systems]. Environmental Sanitation Information Center, AIT, Bangkok, ThailandTH. pp 31–58. 31-58.
===Acknowledgements===
{{:Acknowledgements Sanitation}}
