Difference between revisions of "Pour Flush Pit System without Sludge Production"

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m (Winona moved page Pour Flush System with Twin Pits to Pour Flush Pit System without Sludge Production: Updated name from 2nd edition)
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[[Image:PourFlushSystemWithTwinPits.png | 800px ]]
 
[[Image:PourFlushSystemWithTwinPits.png | 800px ]]
  
This is a water-based system utilizing the Pour Flush Toilet (pedestal or squat pan) to produce a partially digested, humus-like Product, which can be used as a soil amendment. If water is not available, please refer to Systems [[Single Pit System|1]], [[Waterless System with alternating Pits|2]] and [[Waterless System with Urine Diversion|4.]] Greywater can be used in system and does not require separate treatment.  
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This is a water-based system utilizing the Pour Flush Toilet (pedestal or squat pan, U.4) and Twin Pits (S.6) to produce a partially digested, humus-like product, that can be used as a soil amendment. If water is not available, please refer to Systems 1, 2 and 4. Inputs to the system can include Faeces, Urine, Flushwater, Anal Cleansing Water, Dry Cleansing Materials and
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Greywater. The User Interface technology for this system is a Pour Flush Toilet (U.4). A Urinal (U.3) could additionally be used. The Blackwater output from the User Interface and possibly Greywater is discharged into Twin Pits for Pour Flush (S.6) for Collection and Storage/Treatment. The Twin Pits are lined with a porous material, allowing the liquid to infiltrate into the ground while solids accumulate and degrade at the bottom of the pit. While one pit is filling with Blackwater, the other pit remains out of service. When the first pit is full, it is covered and temporarily taken out of service. It should take a minimum of two years to fill a pit. When the second pit is full, the first pit is re-opened and emptied.
  
The inputs to the system can include Faeces, Urine, Flushwater, Anal Cleansing Water, Dry Cleansing Materials and Greywater.  
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After a resting time of at least two years, the content is transformed into Pit Humus (sometimes also called EcoHumus), a nutrient-rich, hygienically improved, humic material which is safe to excavate. Since it has undergone significant dewatering and degradation, Pit Humus is much more hygienic than raw, undigested Sludge. Therefore, it does not require further treatment in a (Semi-) Centralized Treatment facility. The Pit Humus is removed using a Human-Powered Emptying and Transport (C.2) technology and transported for Use and/or Disposal. The emptied pit is then put back into operation. This cycle can be indefinitely repeated.
  
The User Interface Technology for this system is a [[Pour Flush Toilet]]. A [[Urinal]] should only be used in addition to, and not instead of, the Pour Flush Toilet. [[Twin Pits for Pour Flush]] is one of the technologies used for the Collection and Storage/Treatment of the Black water output from the User Interface. The Twin Pits are lined with a porous material that allows the Effluent to infiltrate into the ground while solids accumulate and degrade at the bottom of the pit. While one pit is filling with Blackwater, the other pit remains out of service. When the first pit is full, it is covered and temporarily taken out of service. It should take a minimum of two (2) years to fill a pit. When the second pit is full, the first pit is re-opened and the contents are removed. The Treated Sludge that is generated in the pit after two (2) years is removed and transported for Use and/ or Disposal manually using a [[Human-Powered Emptying and Transport|Human Powered E&T]] Conveyance Technology. Since it has undergone significant degradation, it is not as pathogenic as raw, undigested sludge. There is no need to transport the treated sludge to a (Semi-) Centralized Treatment facility as treatment of the Blackwater takes place onsite.  
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Pit Humus has good soil conditioning properties and can be applied in agriculture (D.4). If there are concerns about the quality of the Pit Humus, it can be further composted in a dedicated composting facility before it is used. If there is no use for the product, it can be temporarily stored or permanently disposed of (D.12).
  
Dry Cleansing Materials may clog the pit and prevent water from infiltrating into the soil and so it should be collected separately and transferred for [[Surface Disposal]].  
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===Considerations===
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This system is suited to rural and peri-urban areas with appropriate soil that can continually and adequately absorb the leachate. It is not appropriate for areas with clayey or densely packed soil. As leachate from Twin Pits directly infiltrates the
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surrounding soil, this system should only be installed where there is a low groundwater table that is not at risk of being contaminated from the pits. If there is frequent flooding or the groundwater table is too high and enters the Twin Pits, the dewatering process, particularly, in the resting pit, will be hindered. The material that is removed should be in a safe, useable form, although proper personal protection should be used during removal, transport and use. Greywater can be co-managed along with the Blackwater in the Twin Pits, especially if the Greywater quantities are relatively small, and no other management
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system is in place to control it. However, large quantities of Flushwater and/or Greywater may result in excessive leaching from the pit and possibly groundwater contamination.
  
Alternatively, the blackwater can be directed towards an [[Anaerobic Biogas Reactor]]. The reactor will function better if animal manure and organic waste are also added; liquid inputs like Greywater should be kept to a minimum. The Biogas that is generated (not shown) can be used for cooking, and the Treated Sludge can be used as a soil amendment.  
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This system is well-suited for anal cleansing with water. If possible, Dry Cleansing Materials should be collected and disposed of separately (D.12) because they may clog the pipe fittings and prevent the liquid inside the pit from infiltrating into the soil. Guidelines for the safe use of Excreta have been published by the World Health Organization (WHO) and are referenced on the relevant technology information sheets.
  
For the Use and/or Disposal component of the System Template, the [[Land Application of Sludge|Application of Sludge]] Technology is utilized. Effluent from the [[Twin Pits for Pour Flush]] is directly infiltrated into the soil onsite from each pit. Therefore, this system should only be installed where there is a low groundwater table that is not at risk of contamination from these pits.
 
  
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[[Image:Pour flush pit system chart.png|none|1000px|]]
  
==Considerations==
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Depending on the Collection and Storage/Treatment technology chosen, the system will depend on different criteria. In the case of the double pits, the system will depend on soil which can continually and adequately absorb moisture; clayey or densely packed soils are not appropriate. The material that is removed should be in a safe, useable form, although the task of removing, transporting and using it may not be favourable in some circumstances. The use of a household biogas digester is best suited to peri-urban or rural areas where there is a source of organic and/or animal waste material and a need for the digested sludge. The piping system for the gas must be well maintained to prevent leaks and potential explosions.
 
 
 
This system is wellsuited for anal cleansing with water. Dry cleansing materials should be disposed of separately because they could easily clog the pit or the reactor, see [[Surface Disposal]].
 
 
 
==References==
 
 
 
* Elizabeth Tilley et.al (2008). [http://www.eawag.ch/organisation/abteilungen/sandec/publikationen/publications_sesp/downloads_sesp/compendium_high.pdf Compendium of Sanitation Systems and Technologies] ([http://www.eawag.ch/organisation/abteilungen/sandec/publikationen/publications_sesp/downloads_sesp/compendium_low.pdf low res version]). Department of Water and Sanitation in Development Countries ([http://www.sandec.ch/ Sandec]) at the Swiss Federal Institute of Aquatic Science and Technology (Eawag). (Provides a full overview of sanitation systems.)
 

Revision as of 00:09, 11 October 2014

PourFlushSystemWithTwinPits.png

This is a water-based system utilizing the Pour Flush Toilet (pedestal or squat pan, U.4) and Twin Pits (S.6) to produce a partially digested, humus-like product, that can be used as a soil amendment. If water is not available, please refer to Systems 1, 2 and 4. Inputs to the system can include Faeces, Urine, Flushwater, Anal Cleansing Water, Dry Cleansing Materials and Greywater. The User Interface technology for this system is a Pour Flush Toilet (U.4). A Urinal (U.3) could additionally be used. The Blackwater output from the User Interface and possibly Greywater is discharged into Twin Pits for Pour Flush (S.6) for Collection and Storage/Treatment. The Twin Pits are lined with a porous material, allowing the liquid to infiltrate into the ground while solids accumulate and degrade at the bottom of the pit. While one pit is filling with Blackwater, the other pit remains out of service. When the first pit is full, it is covered and temporarily taken out of service. It should take a minimum of two years to fill a pit. When the second pit is full, the first pit is re-opened and emptied.

After a resting time of at least two years, the content is transformed into Pit Humus (sometimes also called EcoHumus), a nutrient-rich, hygienically improved, humic material which is safe to excavate. Since it has undergone significant dewatering and degradation, Pit Humus is much more hygienic than raw, undigested Sludge. Therefore, it does not require further treatment in a (Semi-) Centralized Treatment facility. The Pit Humus is removed using a Human-Powered Emptying and Transport (C.2) technology and transported for Use and/or Disposal. The emptied pit is then put back into operation. This cycle can be indefinitely repeated.

Pit Humus has good soil conditioning properties and can be applied in agriculture (D.4). If there are concerns about the quality of the Pit Humus, it can be further composted in a dedicated composting facility before it is used. If there is no use for the product, it can be temporarily stored or permanently disposed of (D.12).

Considerations

This system is suited to rural and peri-urban areas with appropriate soil that can continually and adequately absorb the leachate. It is not appropriate for areas with clayey or densely packed soil. As leachate from Twin Pits directly infiltrates the surrounding soil, this system should only be installed where there is a low groundwater table that is not at risk of being contaminated from the pits. If there is frequent flooding or the groundwater table is too high and enters the Twin Pits, the dewatering process, particularly, in the resting pit, will be hindered. The material that is removed should be in a safe, useable form, although proper personal protection should be used during removal, transport and use. Greywater can be co-managed along with the Blackwater in the Twin Pits, especially if the Greywater quantities are relatively small, and no other management system is in place to control it. However, large quantities of Flushwater and/or Greywater may result in excessive leaching from the pit and possibly groundwater contamination.

This system is well-suited for anal cleansing with water. If possible, Dry Cleansing Materials should be collected and disposed of separately (D.12) because they may clog the pipe fittings and prevent the liquid inside the pit from infiltrating into the soil. Guidelines for the safe use of Excreta have been published by the World Health Organization (WHO) and are referenced on the relevant technology information sheets.


Pour flush pit system chart.png