[[Image:PourFlushSystemWithTwinPits.png | 800px ]]
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 Productproduct, which that 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 4. Inputs to the system can include Faeces, Urine Diversion|, Flushwater, Anal Cleansing Water, Dry Cleansing Materials andGreywater. The User Interface technology for this system is a Pour Flush Toilet (U.4). A Urinal (U.]] Greywater can 3) could additionally be used in system . 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 does not require separate treatmentemptied.
The inputs to After a resting time of at least two years, the system can include Faecescontent is transformed into Pit Humus (sometimes also called EcoHumus), a nutrient-rich, Urinehygienically improved, Flushwaterhumic material which is safe to excavate. Since it has undergone significant dewatering and degradation, Anal Cleansing WaterPit Humus is much more hygienic than raw, Dry Cleansing Materials 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 Greywater/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 Pit Humus has good soil conditioning properties and can be used applied in addition to, and not instead of, the Pour Flush Toiletagriculture (D. [[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 Interface4). The Twin Pits If there 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, concerns about the other pit remains out quality of service. When the first pit is fullPit Humus, 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 can be further composted 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, dedicated composting facility before it is not as pathogenic as raw, undigested sludgeused. There If there is no need to transport use for the treated sludge to a product, it can be temporarily stored or permanently disposed of (Semi-D.12) Centralized Treatment facility as treatment of the Blackwater takes place onsite.
Dry Cleansing Materials may clog ===Considerations=== This system is suited to rural and peri-urban areas with appropriate soil that can continually and adequately absorb the pit and prevent water leachate. It is not appropriate for areas with clayey or densely packed soil. As leachate from infiltrating into 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 so it 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 collected separately used during removal, transport and transferred for [[Surface Disposal]]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 managementsystem 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.
AlternativelyThis system is well-suited for anal cleansing with water. If possible, the blackwater can Dry Cleansing Materials should be directed towards an [[Anaerobic Biogas Reactor]]collected and disposed of separately (D. The reactor will function better if animal manure 12) because they may clog the pipe fittings and organic waste are also added; prevent the liquid inputs like Greywater should be kept to a minimuminside the pit from infiltrating into the soil. The Biogas that is generated Guidelines for the safe use of Excreta have been published by the World Health Organization (not shownWHO) can be used for cooking, and are referenced on the Treated Sludge can be used as a soil amendmentrelevant 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.
[[Image:Pour flush pit system chart.png|none|1000px|]]
==Considerations== 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.)<br>