[[Image:roughing filter chart.jpg|thumb|center|500px|Filter Classification. Chart: [http://www.greenstone.org/greenstone3/nzdl?a=d&c=hdl&d=HASH01ccfcc122c3ed3492c9f50c.6.1&sib=1&p.a=b&p.sa=&p.s=ClassifierBrowse&p.c=hdl SANDEC.]]]
==Construction, operations and maintenance==
==Costs==
'''Initial cost''': Reported construction costs are US$ 20–40 per m3 of water per day, for a structure designed to be in operation for 24 hours a day.
==Field experiences==
'''African Killer Bees Supported Sustainability'''<br>
The rapid sand filters of Salaga, a district centre located in West Africa, were never filled with filter media and the population of the town was therefore exposed to unsafe water. The old treatment plant had to be extended and replaced by an appropriate treatment scheme. Roughing and slow sand filters were thus tested in a pilot plant shaded by a large baobab tree. The location was chosen by the external experts suffering from the Ghanaian sun. The pilot plant was constructed by the local water authority, and the expatriates supervised the start of the field tests. However, African killer bees also chose the same large baobab tree as their habitat and were very much attracted by the white skin of the foreigners. Under remote supervision by the expatriates, the field tests were continued by the local staff which gained experience and confidence in a treatment scheme they wit/have to run in future at full scare and without foreign assistance. Thus, the African killer bees somehow contributed to developing local sustainability.
==Acknowledgements==
* Brikke, François, and Bredero, Maarten. ''[http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CC0QFjAB&url=http%3A%2F%2Fwww.who.int%2Fwater_sanitation_health%2Fhygiene%2Fom%2Flinkingintro.pdf&ei=cwJpT-zaO-OiiQKCst2rBw&usg=AFQjCNEWOQhTgF3a7lzhuw5OA2KmbVGxcA&sig2=Rt2EURUyGVqDcwFg6p0xAw Linking technology choice with operation and maintenance in the context of community water supply and sanitation: A reference document for planners and project staff]''. World Health Organization and IRC Water and Sanitation Centre. Geneva, Switzerland 2003.
* [http://www.greenstone.org/greenstone3/nzdl?a=d&c=hdl&d=HASH01ccfcc122c3ed3492c9f50c.1&sib=1&p.a=b&p.sa=&p.s=ClassifierBrowse&p.c=hdl Surface water treatment by roughing filters - A design, Construction and Operation manual (1996)]. SANDEC.