}}
==Technical specificationConstruction, operations and maintenance== ====Operation====
The top 5 to 10 cm of wet sand must always be under oxygen rich water. Therefore, the system needs continuous water flow
Large and fine particles of suspended matter are deposited on the surface of the filter bed by the action of mechanical straining and sedimentation, respectively. The colloidal and dissolved impurities are removed by adsorption, whilst the organic matter is converted into organic salts by the purification mechanics. The filtered water is collected at the bottom via pipe system. Most microbiological action takes place in the ‘Schmutzdecke’ (bio film) formed in the fabric filter at the top of the sand bed.
====Treatment Efficiency====Filter can be easily assembled locally available material like sand, pebbles and water tank. However, fitting material can be easily transported, if not available locally. TARA Environment Monitoring Facility also manufactures filters which employ the SSF technique. In this case, customers in addition require a water pump to fill the overhead tank and power supply to pump water into the tank - an electricity connection or generator.
====Maintenance====
The system is designed to have very little maintenance. The filter does require regular cleaning, thought the frequency depends on input water quality (turbidity and bacteria contamination) and filtration rate. Cleaning operation includes cleaning of fabric filter and top sand layer. Fabric filter requires cleaning twice in a year for turbidity 10 – 15 NTU input water. To simplify cleaning operation, backwashing facility is also provided.
User’s instruction manual with illustrative diagrams is provided. After maintenance, filter bed should be kept level.
====Manufacturing====
Filter can be easily assembled locally available material like sand, pebbles and water tank. However, fitting material can be easily transported, if not available locally.
TARA Environment Monitoring Facility also manufactures filters which employ the SSF technique. In this case, customers in addition require a water pump to fill the overhead tank and power supply to pump water into the tank - an electricity connection or generator.
====Estimated Lifespan====
The plastic parts last up to 5 years.
==CostCosst==
{{Treatment_Cost2
|CapCost= Rs. 80.000 = ~ € 1.300
These costs assume the lifetime is 15 years with daily production of 2.750 litres; O&M and salary included; salary is based on 1 working day of operator, assuming an average gross annual income of € 500 in developing countries.
==Country Field experiences== ==Manuals==
==Movies== ==FootnotesReference manuals, operations and maintenance==
==Acknowledgements==
==References==