Arsenic Biosand Filter: Sustainable Implementation of an Appropriate
Household Drinking Water Filter for Rural Nepal
Team Leader: Susan Murcott (murcott@mit.edu), MIT - Team Members: Tommy Ngai (ngait@mit.edu), MIT - Sophie Walewijk, Stanford University - Roshan Shrestha, ENPHO - Heimo Ojanen, RWSSSP
Lead Organization: Massachusetts Institute of Technology
(MIT), Department of Civil and Environmental Engineering
Partner Organization 1: Environment and Public Health
Organization (ENPHO), Nepal
Focus on Nepal
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Project Scope
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Total population: 24 millions
Rural population: 20 millions
Population below poverty line: 11
millions
Annual per capita income: US220
12th poorest country in world,
poorest in South Asia
Literacy rate for women: 24%
Children suffering from stunting due
to water-borne disease: 51%
To provide safe drinking water to 25 rural villages, a population of about 10,000
To educate and empower individuals toward safe water provision
Project duration = 8 months
Our Solution – Arsenic Biosand Filter
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(World Bank 2002; UNICEF 2003)
What Are The Problems/ Issues?
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Unsafe Drinking Water:
• 90% of the population in the rural Terai
depends on groundwater for drinking water.
• 20+% of the Terai tube well water is
contaminated with arsenic, causing
arsenicosis, vascular diseases, and cancer
of the lungs, bladder, and kidney.
• 40+% of the Terai tube well water is
contaminated by pathogens, causing
diarrhea, intestinal worms, trachoma,
cholera, stunting, etc.
Technological Deficiencies:
• Many previous aid projects have failed in rural
areas due to the use of inappropriate
technologies.
• Many current point-of-use technologies treat
pathogen and arsenic separately, resulting in
complicated and time consuming treatments.
• Many current technologies have low flow rate,
insufficient contaminant removal efficiency,
complex production process, reliance on
material unavailable in rural villages, high
replacement cost.
Partner Organization 2: Rural Supply and Sanitation
Support Programme (RWSSSP), Nepal
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To provide safe water and health improvement for
millions of poor in the Terai, MIT, ENPHO and
RWSSSP developed an innovative, award-winning
filter (the Arsenic Biosand Filter, or ABF) for
simultaneous arsenic and pathogen removal.
The ABF was designed based on iterative and multidisciplinary thinking inherent in the sustainable
development concepts.
The design was optimized after five years of
research, extensive field experiments, comparison
with competing technologies available in Nepal,
Bangladesh, India, Haiti, Nicaragua, and other
countries, and field assessments of the social,
economical, and political constraints of Nepal
A 12-months pilot study showed very favorable
performance and user acceptability.
Some villages are only
accessible by foot
ABF can be easily
constructed by trained
technicians
Features & Innovations:
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Women are usually responsible for
collecting drinking water for their
household
Tube well water is
contaminated by arsenic
and pathogens
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Simultaneous removal of arsenic and pathogens by
combining the strength of two proven technologies: ironhydroxide, and biosand filter.
Robust removal processes based on simple chemistry
Aesthetically pleasing filtered water – removal of iron,
turbidity, color, etc. from raw water.
High flow rate – time savings for women to pursue other
productive work.
Easy operation and minimal maintenance – suitable for the
often illiterate women and children.
Simple construction, can be done by trained local
technicians, and using materials available in rural villages.
Low-cost
Filter monitoring and user feedback are
important parts of the iterative design process
Contaminated Water In
Implementation Deficiencies:
• Failure of many previous aid projects in rural
areas is also a result of non-sustainable
implementation schemes.
• Problems include lack of user understanding of
the technology, lack of user participation,
inadequate long-term monitoring, inadequate coordination and transparency among participating
parties, etc.
This coagulation-filtration
technology is complicated to
use and time-consuming
Replacement parts for this U.S.manufactured water treatment
system are unavailable in Nepal
Iron Nails
Water
Filtered
Water
Fine Sand
Results:
• Currently many villagers have no choice but to
drink contaminated water. Women and children
are often most vulnerable to water-borne
diseases, which are preventable.
Coarse Sand
& Gravel
Women and children are often
most vulnerable to water-borne
diseases
This person suffers from skin
diseases associated with arsenic
poisoning
A cross-section diagram of an Arsenic
Biosand Filter (ABF)
Large concrete version (left) and Plastic version (right) of the
Arsenic Biosand Filter (ABF)