- Requires expert design and construction supervision. <br> - Requires repairs and removals of blockages more frequently than a Conventional Gravity Sewer. <br> - Requires education and acceptance to be used correctly. <br> - Effluent and sludge (from interceptors) requires secondary treatment and/or appropriate discharge.<br>-High water consumption for excreta removal.
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==Adequacy==
The septic/interceptor tank must be regularly maintained and desludged to insure optimal performance of the Solids-Free Sewer network. If the pre-treatment is efficient, the risk of clogging in the pipes is low, but some maintenance will be required periodically. The sewers should be flushed once a year as part of the regular maintenance regardless of their performance.
==Acknowledgements==
{{:Acknowledgements Sanitation}}
==Referencesand external links== * 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.)
* Azevedo Netto, MM. and Reid, R. (1992). Innovative and Low Cost Technologies Utilized in Sewerage. Environmental Health Program, Technical Series No. 29. Pan American Health Organization, Washington DC. (A Short summary and component diagrams-Chapter 5.)