MIT/CITE – USAID: Evaluation of water filters in Ahmedabad, Oct 2015.
| Complete Report | Summary |
Background – CITE’s household water filter evaluation allowed us to study innovations with the potential to better the lives of India’s “water poor”—the 76 million people in the country who lack improved drinking water.
CITE teams studied over 100 models of householder water filters from nine major brands available on the market in Ahmedabad, India. These models fell into three main categories: conventional particle filtration (cloth/jali mesh), gravity non-electric filters, and reverse osmosis filters.
In Ahmedabad, MIT students and researchers worked closely with students from local Indian universities to conduct the evaluation. Another student team spent the summer in the Consumer Reports labs in Yonkers, New York conducting lab tests of the same models being tested in the field.
CITE used multi-criteria analysis and Consumer Reports-style rating charts to guide its water filter evaluation report, which was released in October 2015.
Key Findings
Suitability
- Cloth and jali filters are cheap and common among low-income users, but are not effective in reducing E.coli, or turbidity.
- Gravity non-electric filters are moderately priced and far more effective than cloth filters at reducing E.coli and turbidity.
- Reverse osmosis is a popular type of water filter system perceived as the best, but most of these systems are not an affordable option for the poor. Moreover, these filters generate wastewater at rates triples that of the clean water they produce—a negative environmental impact in a water scarce region.
Scalability
- Postponed assembly at the retail level for certain water filter products can be very effective in scaling the supply chain. The locally branded “Dolphin” reverse osmosis water filters assembled by the distributors and retailers are promising from a scalability perspective.
- Water filters offer a good retail entrepreneurial opportunity since the assembly process is straightforward and requires few technical skills.
- A low-priced water filter is not sufficient for reaching rural populations. The more affordable gravity non-electric models are not readily available in rural areas, where they may be needed most.
Sustainability
- Water filter use seems to be dependent on use of water filters in the past and peer effects. This suggests that sustainable water use may be better suited to community- and neighborhood- scale interventions, rather than market interventions, at least in the short-run.
- A majority of water filter purchasing decisions were influenced by the buyer’s close network, most often a family member.
- Knowledge about household water filters designed for the bottom of the pyramid is low among that market segment. Technology adoption proves difficult when one’s peers do not have knowledge about a particular product.
