Pond Sand Filters

Needs Address

Supply of fresh water for domestic use

Adaptation effects

• Supplies an alternative supply of safe water when other sources are unavailable
• Improved water security
• Enable diverse livelihood options

Overview and Features

Pond Sand Filters (PSFs) are used to clean contaminated bodies of water, particularly surface waters of freshwater ponds that collect rainwater. Contaminated water passes through a pre-treatment chamber of gravel and a filter made from sand to block the sand and other solids within the water and remove pathogens. For smaller grains, chemical and biological processes can be used alongside this physical process to aid the filtration of the water.

Cost

• Costs vary dependent on the location and size of the systems
• E.g. In Bangladesh, installation for 15 households is estimated to be approximately USD 150 per household, for 1000 households it is estimated at USD 10 per household
• Operation and management costs are fairly low

Energy source

Human labour for construction, operation and maintenance

Ease of maintenance

• Maintenance is relatively easy, but necessary for sustaining yield and quality of filtered water supply
• Includes regularly removing sludge, cleaning the upper filtration layer every 1-5 months and replacing when necessary

Technology performance

PSFs depend upon pond water availability and therefore cannot always be used year round 

Considerations

• Further filtration or treatment for household use is advised e.g. ceramic pot filtration or chlorination
• Removed sand and sludge must be appropriately disposed to avoid health risks and further water contamination

Co-benefit, suitability for developing countries

• PSFs have a limited filtering capacity therefore may not be enough for reliable supplies for an entire community
• Relatively easy to construct and maintain
• Organisations are often able to assist the design process
• Community management is needed to ensure regular cleaning of filters and monitor water quality – training is often needed for this
• Depending on the location of ponds, dependence on this water supply may demand considerable travel for water collectors, who are often women and children

Information Resources

Astra, Bangladesh. N.d. Technology Database. Available from: http://astradst.info/Tool/Technologies [19 January 2014]

DPHE and UNICEF 1989. A Report on the Development of Pond-Sand Filter. Department of Public Health Engineering, Dacca.

UNEP, n.d. Sourcebook of Alternative Technologies for Freshwater Augmentation in Some Countries in Asia. Available from: http://www.unep.or.jp/ietc/publications/techpublications/techpub-8e/filtration.asp [19 January 2015]