[[Image:Icon_sludge.png|right]]
[[Image:Rota sludge in action.jpg|thumb|right|175px200px|Rota sludge in action]][[Image:Deep drilling with the rota sludge.jpg|thumb|right|175px200px|Deep drilling with the rota sludge]]
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The Rota Sludge is a manual drilling technique based on the [[Sludging - Asian sludge |Asian sludge]] technique, and adapted for harder soil types. To drill through the harder layers, a hardened drill bit and weight have been added. Just after the downward movement of the drill pipes the drill bit is rotated a quarter turn, thus chiselling the bottom of the hole. Water is circulated to bring the cuttings to the surface.
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! width="50%" style="background:#efefef;" | Advantages
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| valign="top" | - Easy to handle and a temporary casing is normally not needed. It is possible to construct the drilling equipment locally.<br>
==Construction, operations and maintenance==
[[Image:Diagram of a rota sludge.jpg|thumb|right|175px200px|Diagram of a rota sludge]][[Image:Rota_sludge_well_drilling.PNG|thumb|right|175px200px|Drilling a 20 m deep well in Chinandega, Nicaragua, with the Rota-sludge method. Photo: Netherlands Water Partnership.]][[Image:Rota sludge drill bit.jpg|thumb|right|175px200px|Rota sludge drill bit]]
Cow dung is mixed with water to create a very low cost drilling fluid. It may take several weeks after the drilling is finished for the pathogens (bacteria) to die and disappear completely out of the well.
The Rota Sludge is used in Nicaragua, Tanzania, Madagascar, Ghana, Senegal, Mauritania and Niger.
==Manuals, videos and links==* Arjen van der Wal & Robert Vuik, [http://www.practica.org/wp-content/uploads/services/publications/drilling%20manuals/EN/sludging%20_final%20version_lr%20310811%20full%20ENG.pdf Sludging: Manual Drilling Series. Technical Training Handbook on Affordable Manual Well Drilling]. Practica Foundation, June 2011 (2nd edition). French version: [http://www.practica.org/wp-content/uploads/services/publications/drilling%20manuals/FR/sludging_final%20version-lr%20310811%20full%20FR.pdf FORAGE A LA BOUE : Serie forage manuel].
*[http://www.practicafoundation.nl/wp-content/uploads/PDF/Practica%20drilling%20Rs%20versie%201th%20september%2005.pdf Rota-sludge and stone hammer drilling, Part 1, Drilling manual]. Produced by [http://www.practicafoundation.nl PRACTICA Foundation] and [http://www.etc-international.org/index.php?id=41 ETC Foundation].
*[http://www.practicafoundation.nl/wp-content/uploads/PDF/practica-production-rs-versie-1th-september-051.pdf Rota-sludge and stone hammer drilling, Part 2, Production manual]. Produced by [http://www.practicafoundation.nl PRACTICA Foundation] and [http://www.etc-international.org/index.php?id=41 ETC Foundation].
==Manuals* [http://www.practica.org/products/drilling-wells/ Drilling & Wells], videos, and links==Practica Foundation. * General info on manual well drilling [http://www.rwsn.ch/prarticle.2005-10-25.9856177177/prarticle.2005-10-26.7220595116/prarticle.2005-11-15.6127855822 Rural Water Supply Network]
{{#ev:youtube|MvebFHCjCvk|200|auto|<font size="2"><center>Rota sludge drilling in <br>Madagascar, January 2008</center></font>}}
* [http://www.practica.org/products/drilling-wells/ Drilling & Wells], Practica Foundation.
* General info on manual well drilling [http://www.rwsn.ch/prarticle.2005-10-25.9856177177/prarticle.2005-10-26.7220595116/prarticle.2005-11-15.6127855822 Rural Water Supply Network]
== Acknowledgements==
* The basis for the material on this page was obtained from a desk study shortly to be published on the website of the [http://www.practicafoundation.nl/ Practica Foundation], and from the [http://www.rural-water-supply.net/ Rural Water Supply Network], and specifically its [http://www.rural-water-supply.net/en/implementation/manual-drilling manual drilling section].
* [http://www.lboro.ac.uk/well/resources/technical-briefs/43-simple-drilling-methods.pdf 43. Simple drilling methods.] WEDC.