Updated on January 10, 2024


Created on September 27, 2018

DHAN Biosand Filters


DHAN Biosand Filters are household devices that remove pathogens such as bacteria, protozoa and virus found in drinking water.

Tested By
  • Centre for Affordable Water and Sanitation Technologies (CAWST)
Content Partners
  1. Centre for Affordable Water and Sanitation Technologies (CAWST)


Product Description

DHAN Biosand Filters are household sand filters developed by Canadian engineers promoted by DHAN Foundation. This household devices is build with local materials and filter water from wells, tanks, and oorani.

Target SDGs

SDG 6: Clean Water and Sanitation

SDG 3: Good Health and Well-Being

Market Suggested Retail Price


Target Users (Target Impact Group)


Distributors / Implementing Organizations

DHAN Foundation

Competitive Landscape

Direct competitors include Hydraid® BioSand Filter.

Manufacturing/Building Method

DHAN foundation provides a training course to artisans and users to build Biosand Filters from locally available concrete and sand. DHAN also sells their own manufactured filters produced in 5 production centres in Tamil Nadu, India. Manufacturing instructions for Biosand filters are openly available from CAWST.

Intellectural Property Type


User Provision Model

Users can contact the DHAN Foundation directly.

Distributions to Date Status

As of 2014, 3500+ Biosand Filters installed.

Target use case

Household use

Manufacturer-specified flow rate (L/hr)


Bacteria reduction

Bacterial removal efficiency of 94.7%


Protozoa reduction


Virus reduction

4  – 7 log10 reduction of MS2 bacteriophage

Heavy metals and/or arsenic reduction


Maximum recommended influent turbidity level (NTU)


Effluent turbidity levels (NTU)


Manufacturer-specified volume between cleaning (L)


Material of construction

Cement, sand and gravel

Design Specifications

Water is poured into the top of the DHAN Biosand filter and passes through layers of sand. The filtered water is collected in another storage container at the base. The pathogens are removed due to a combination of biological and mechanical processes. Between uses, a 5 cm deep layer of water is maintained above the sand all times, allowing for a biolayer to remain, which helps in the removal of bacteria and viruses. This feature distinguishes the Biosand filter from other slow sand filters. The product schematics are shown in the image.   Filter lid: Prevents contaminants from entering the filter. Diffuser plate: Protects the biological layer from damage when water is poured into the filter. Standing Water Layer: When the water stops flowing, a 5cm water layer is kept at the top which keeps the biological layer alive during pause periods. Filtration Sand: Traps organic and inorganic material at the top of the filter media. Outlet tube: Conducts water from filter base to outside. Medium Gravel/Course sand: presents fine sand from plugging drainage gravel. Drainage Gravel: promotes vertical flow of water into collector pipe. Prevents smaller gravel to block the outlet tube.

Product Schematics

Technical Support

DHAN foundation conducts training workshops, provides manual and CD for technical assistance. A detailed technical manual is available by CAWST as well.

Replacement Components

All the manufacturing and replacement components are intended to be available locally; including sand, concrete, and PVC piping.


30 years

Manufacturer Specified Performance Parameters

This biosand filter removes iron and manganese and has >97% pathogen removal efficiency.

Vetted Performance Status

Water samples of 50 DHAN Biosand filters tested in India for microbial performance showed >80% pathogen removal efficiency. Additionally, there have been many laboratory and field tests performed on with Biosand filters; including quality control in the production of Biosand filters in Zambia.


Important safety measures include: (1) Placing the filter inside the house on a levelled spot, (2) Cleaning the filter components and surroundings regularly, (3) Avoiding direct contact with spout and filter, (4) Measuring outlet flow rate from the sprout frequently to detect if maintenance is required.

Complementary Technical Systems

Suitable containers for water storage.

Academic Research and References

Several Biosand filter publications are available on CAWST website including:

Ngai, T.K.K. and Fenner, R.A. 2014. Designing programme Implementation Strategies to Increase the Adoption and Use of Biosand Water Filters in Rural India, Water Alternatives 7(2): 320-341

Wang, Narihiro, et al. 2014, MS2 Bacteriophage Reduction and Microbial Communities in Biosand Filters, Environ. Sci. Technol., 2014, 48 (12), pp 6702–6709.

“DHAN Foundation,” Dhan.org. Available: https://www.dhan.org/

T. K. K. Ngai and R. A. Fenner, “Market suggested retail price”. Available: https://www.water-alternatives.org/index.php/all-abs/249-a7-2-3/file

“IndiaMART: ” Indiamart.com. Available: https://www.indiamart.com/proddetail/biosand-filter-11924861255.html

“Goal 6,” Sdgs.un.org. Available: https://sdgs.un.org/goals/goal6

“Archived Perspective Notice,” Sswm.info, 05-Feb-2018. Available: https://sswm.info/sites/default/files/reference_attachments/CAWST%202009%20Biosand%20Filter%20Manual.pdf

M. Theses and A. J. Sisson, “Bacteria reduction,” Gvsu.edu. [Online]. Available: https://scholarworks.gvsu.edu/cgi/viewcontent.cgi?referer=https://www.google.co.in/&httpsredir=1&article=1038&context=theses

A. Cawst Participant Manual, Available: https://www.ideassonline.org/public/pdf/AguasanPeru-BSF_for_Techs_Participant_Manual_BSF_Construction_Manual_With_Appendices_2012-01.pdf

D. M. Suaquita, “Bio-sand technology adopted in India for sustainable water filtering,” Ideassonline.org. Available: https://www.ideassonline.org/public/pdf/BioSandIndia-ENG.pdf

N. Chan, L. Mitchell, T. Ngai, S. Li, and Canada, “Quality control in the decentralized production of biosand filters: a pilot workshop in Zambia,” Lboro.ac.uk. Available: https://wedc-knowledge.lboro.ac.uk/resources/conference/40/Chan-2785.pdf

CAWST, “Biosand Filter Information,” Centre for Affordable Water and Sanitation Technology (CAWST). Available: https://www.cawst.org/services/expertise/biosand-filter/more-information

CAWST, “[No title],” Centre for Affordable Water and Sanitation Technology (CAWST). Available: https://www.cawst.org/blog/india-bold-hearts-the-village-of-women

CAWST, Centre for Affordable Water and Sanitation Technology (CAWST). Available: https://www.cawst.org/blog/india-the-power-of-education-pusphavanam-women

Compliance with regulations


Evaluation methods

Field and laboratory evaluation in Haiti. Also, the manufacturer tested for microbial contamination using Oxfam Delagua Test kit.

Other Information

CAWST Blog India: Bold Hearts- The Village of Women

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