Our Impact

Results at a Glance:

  1. Dispensers for Safe Water has been proven over the last six years.

  2. We have steadily grown to an impressive user base of 4.0 million people.

  3. We have also maintained the holy grail of water products: Sustained user adoption.

  4. Our average program-wide adoption rate is 51% (as of July/August 2019).



 Our adoption rate is an important measure of the use of dispensers. It is a percentage of randomly sampled households that tested positive for Total Chlorine Residual in their drinking water during an unannounced visit. 1.5% of all dispensers are evaluated every month. For the first three months of evaluation in a new region, 2% of all dispensers are monitored. A random selection of 8 households are interviewed at each dispenser by our Monitoring and Learning Team.  



The Monitoring, Learning and Information System (MLIS) team supports the Dispensers for Safe Water program in collecting data at all stages of program implementation: from identification of suitable water points, to dispenser installation, to monthly performance monitoring. 

Performance monitoring of Dispensers for Safe Water is done on a monthly basis by MLIS data monitors across Kenya, Uganda, and Malawi. Data is collected from a randomized sample of of all installed dispensers to ensure an 80 percent confidence interval and a 10 percent margin of error. The sampling is stratified by geography (program, country, and field office). MLIS monitors interview eight households at every water point visited. 

The MLIS monitors collect data electronically using smartphones with the Open Data Kit (ODK) software installed. The MLIS monitors do an initial spot check at the sampled water point to check that the chlorine dispenser is functional and contains chlorine. They then conduct household surveys to measure rates of chlorine adoption in the community. This is done using a chlorine testing kit which tests for the Total Chlorine Residual (TCR) in household water. 

The MLIS data management team cleans any incoming data from the field and it is then passed on to the data analysis team. Every two months the analyzed data is shared with program teams. The results are broken down by field office, country program, and overall adoption results. Results are also shared with teams on the MLIS management information system, or progMIS, so that all staff have immediate access to the uploaded data. 

Unsafe Drinking Water: Our

Globally, about 842,000 people die each year from diarrhea caused by unsafe drinking-water, sanitation, and hand hygiene. An estimated 525,000 children under the age of five die from diarrhea each year, often as a result of unsafe water. Childhood diarrhea is still the second-leading cause of childhood mortality. 

The current approach to water has emphasized access to water, often by building a large number of wells. However, we now know that access is not enough. Water may be relatively safe to drink at the well, but does not stay safe in transit or when it is stored in homes. Additionally, a focus on market solutions and pay-for-water schemes has not shown results for very poor communities. 

Consequently, very rural and very poor communities are still underserved in Sub-Saharan Africa, especially.



Dispensers for Safe Water

What is Dispensers for Safe Water?

Dispensers for Safe Water is a seemingly simple solution to the problem of unsafe water in rural and remote communities. 

  • We place chlorine dispensers in the immediate vicinity of wells and other water sources.

  • Community members go to their water source to fetch water, place their bucket or jerrican under the dispenser, turn the valve to dispense a correctly measured amount of diluted chlorine, and then fill the bucket with water.

  • The chlorine disinfects the water as a community member is walking home, and by the time he or she arrives, much of the chlorine smell has dissipated and they are left with clean, safe water that stays safe for 2-3 days.

Five Reasons Why Dispensers Work:


Dispensers are installed right next to the water source – they can’t be missed. The use of dispensers is also free. That is controversial in some circles that emphasize pay-for-service water. However, we looked carefully at the evidence, and it shows that people are reluctant to pay for preventative healthcare products and services. This is especially true for the very poor. Additionally, in every community with a dispenser, there is an elected, local community promoter who is responsible for the dispenser and educates villages on how to use it.


Dispenser for Safe Water runs a very sophisticated maintenance and supply chain. In order to be most successful, chlorine dispensers require high rates of usage by people in a given village. We know, through our data collection, that there are a couple different components that contribute to higher usage rates:

  • Dispensers have to be functional, so we have circuit riders who maintain and repair dispensers in even the most remote locations.

  • They have to be full, so our circuit riders deliver chlorine to our local promoters in regular intervals (usually every three months).


Dispensers for Safe Water are, according to a 2007 academic study, more cost-effective than other solutions like solar disinfection, flocculation, and ceramic filters.

In fact, we’re now doing a very detailed cost analysis to more thoroughly understand how dispensers compare to other water products. 

Not only that, but the cost per person for chlorine dispensers decreases as we continue to scale and reach more people.


Safe water has become an equity issue. We’re reaching the people left behind by the current approaches to safe water: that cohort of people who are very rural and very poor in Sub-Saharan Africa.

We are ultimately targeting health impacts and are modeling the rates of averted diarrhea and averted DALYs with Dispensers for Safe Water.

DALY is an actuarial term that tries to calculate the number of years lost due to ill-health, disability or early death — it’s used as a way to compare the overall health and life expectancy in different countries, especially developing countries versus more developed countries.

We know that chlorine kills bacteria, and we know from various evidence that bacteria reduction reduces diarrhea. In fact, water systems the world over routinely chlorinate water — the water you brush your teeth with is chlorinated.  We can measure self-reported diarrhea, and while we cannot measure actual diarrhea reductions due to the cost and complexity of direct measurement, our detailed models suggest that we avert nearly 450,000 cases of diarrhea per year and nearly 400 deaths of children under the age of 5 per year.


Lastly but perhaps most importantly, Dispensers for Safe Water are a rigorously tested and proven solution. Our approach is based on a series of randomized controlled trials by Harvard and Berkeley researchers who tested chlorine dispensers in Kenya against a variety of other water treatment options. They found two things: 1) chlorine dispensers had a much higher usage rate than comparable treatments, and 2) use stayed high over time. We speak more about the available evidence below.

Dispensers is a poster child for how Evidence Action works – we look for evidence of a solution that works, and then turn it into a scalable solution for millions of people.

Where Dispensers for Safe
Water Operates


  • Evidence Action today provides over 2.0 million Kenyans with sustained access to clean water in the home with 18,253 dispensers installed to date (as of October 2018).

  • Achieve sustained adoption rates by users of 50% in Kenya.

  • Carbon credits generate revenue for service delivery into the future, making it possible for communities to reap benefits off their carbon offsets.


  • Evidence Action currently provides over 620,000 Malawians with sustained access to clean water with 3,759 dispensers installed to date (as of October 2018).

  • Achieve sustained adoption rates by users of 75% in Malawi.

  • Evidence Action is certified to generate carbon credits in Malawi that generate revenue for ongoing operations.



  • Evidence Action provides roughly 1.3 million Ugandans with access to safe drinking water with 5,153 dispensers installed (as of October 2018).

  • Achieve sustained adoption rates by users of 60% in Uganda.

  • Carbon credits were certified in mid-2014, generating revenue for ongoing operations.

The Evidence For Dispensers For Safe Water

You can read our discussion of the evidence supporting chlorine dispensers here, but in short: 

  • The Cochrane Review evaluated water interventions at point-of-use as well as more traditional water source improvements. The review covered 38 independent comparisons from 30 trials that involved more than 53,000 people. The review found that “in general, such interventions were effective in reducing episodes of diarrhea. Household interventions were more effective in preventing diarrhea than those at the source.”
  • A 3ie review covered 65 rigorous impact evaluations of water, sanitation and/or hygiene interventions on diarrhea morbidity, covering 71 distinct interventions assessed across 130,000 children in 35 developing countries during the past three decades. It concludes that point-of-use water quality interventions appear to be highly effective – and indeed, more effective than water supply or source treatment in reducing diarrhea – but that this is very sensitive to the ability of the program to sustain high rates of product adoption. A point-of-use product cannot provide health benefits if people do not use it.
  • Researchers Arnold and Colford conducted a systematic review of all studies that measured diarrheal health impacts in children and the impact on water quality of point-of-use chlorine drinking water treatment. Twenty-one relevant studies were identified and combined using meta-analysis to provide summary estimates of the intervention effect. The intervention reduced the risk of child diarrhea by 29%, and up to 40% if you look at effects only among people actually using the product, as opposed to only being offered it.

There are shortcomings to the existing epidemiology literature. The reviews highlight the short duration of the studies that are available, and there is a need for more trials that are blinded or rely on objective measures of health outcomes instead of self-reported diarrhea.

Revenue Through Carbon

While dispenser access is free to users, we do not rely solely on donations or grant funding to cover the costs of this rural water service.

  1. Dispensers have an ingenious revenue mechanism. We generate carbon credits because chlorine dispensers avert carbon emissions – people do not need to boil water to disinfect it. This is an interesting part of the Kyoto Protocol that is complicated but pertains to providing incentives for developing countries to leapfrog straight to cleaner technologies. We describe it here in detail. Because dispensers aren’t just a better way to provide safe water but are also a cleaner way, we can make use of this program.
  2. We worked with carbon experts and are now certified to generate credits in all three countries where we operate. We then issue and sell carbon credits on the voluntary and compliance carbon markets. Our carbon issuance is audited by highly reputable carbon auditors.

  3. We use the revenue earned from these carbon sales to reinvest in the program.



The Greatest Hits of 2019

The last year was tremendous, not just for us, but for the entire field of evidence-based, international development. Take a look at our top highlights from 2019, as well as some of the tough decisions we had to make along the way.

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G-United/Winning Start Implementation Toolkit

Evidence Action has prepared a comprehensive program toolkit, in order to guide potential technical and public partners in providing technical assistance to programs similar to G-United. We encourage other governments, technical partners and organizations to use the materials, tools, processes and strategies described here.

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