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Impact Rating

Evidence Action

Top Clean Water Nonprofit

Impact: $0.50 provides clean water to a person for a year.

Dispensers for Safe Water meets the benchmark for high cost-effectiveness. The nonprofit's cost to provide clean water is less than 75% of the local costs.

Note: The impact of this program may not be representative of the entire operation of Evidence Action.


Governance: Passes checks


Evidence action aims to be a world leader in scaling evidence-based and cost-effective programs to reduce the burden of poverty by building a world where hundreds of millions of poor people have better opportunities and their lives are measurably improved.


Clean Water

Rated Program

Dispensers for Safe Water

Program Geography

Sub-Saharan Africa


Washington, DC

Donations processed by the nonprofit.


Clean Water

Rated Program

Dispensers for Safe Water

Program Geography

Sub-Saharan Africa


Washington, DC

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Rated Program


Dispensers for Safe Water


Evidence Action distributes water purification systems to beneficiaries.

Program Type

Water Purification

Beneficiaries Served

People living in poverty


Sub-Saharan Africa

Outcomes: Changes in people's lives. They can be caused by a nonprofit.

Costs: The money spent by nonprofits and their partners and beneficiaries.

Impact: The cost to achieve an outcome.

Cost-effectiveness: A judgment as to whether the cost was "worth" the outcome.


Outcome Metric

A year of clean water provided to a person.

To calculate impact, we estimate how many outcomes the nonprofit caused.

Data Source

Output data collected during the program. Evidence Action publicly reports data on how many purifiers it distributes and how many people a purifier serves, which we use to calculate how many person-years of clean water a nonprofit provides.

Time Period of Data

Jan. 1, 2018, to Dec. 31, 2018

Ratings are based on data the nonprofit itself collects on its work. We use the most recent year with sufficient data. Typically, this data allows us to calculate direct changes in participants' lives, such as increased income.

Method for Attributing Outcomes

We estimate the number of person-years of clean water the nonprofit provides by comparing the person-years actually achieved to the person-years that would have been achieved even in the absence of the nonprofit (the “counterfactual”). Some beneficiaries might have accessed clean water from other providers or on their own; these counterfactual successes must be netted out of the successes we observe. Otherwise, we would be attributing a change in a person’s life (gaining clean water) to the nonprofit when it would have happened anyway. Few nonprofits estimate the counterfactual themselves, so we construct our own counterfactual estimate based on research and publicly available data. We research the average rate with which clean water access is increasing year over year in that location, and assume that, if the nonprofit had not intervened, that trend would have continued.

We don't know if the observed changes were caused by the nonprofit's program or something else happening at the same time (e.g. a participant got a raise). To determine causation, we take the outcomes we observe and subtract an estimate of the outcomes that would have happened even without the program (i.e. counterfactual outcomes).


Data Source

Cost data reported by Evidence Action and data and assumptions about partner and beneficiary costs.

Cost Calculation

$4,285,899 program costs + $0 partner costs + $0 beneficiary costs = $4,285,899 total costs

After estimating the program's outcomes, we need to determine how much it cost to achieve those outcomes. All monetary costs are counted, whether they are borne by a nonprofit service deliverer or by the nonprofit’s public and private partners. In-kind donations, of labor or supplies, are not counted.


Impact Calculation

$4,285,899 total costs / 9,144,994 person-years of clean water = roughly $0.50 provides clean water to a person for a year.

Numbers may not divide precisely due to rounding and time discounting.

We calculate impact, defined as the change in outcomes attributable to a program divided by the cost to achieve those outcomes.


Benchmark for Rating

Impact ratings of water purification programs are based on the cost to provide clean water relative to the market cost that a person incurs to buy water in that country. Programs receive 5 stars if they provide water for less than 75% of the estimated market costs, and 4 stars if they do so for less than 125%. If a nonprofit reports impact but doesn't meet the benchmark for cost-effectiveness, it earns 3 stars.


The nonprofit's cost to provide clean water is less than 75% of the local costs.

Why We Could Be Wrong

We welcome your suggestions for improving our methodology. Our methodology section includes explanations of how we mitigate these issues.

  • The outcome could oversimplify total impact. Using “person-years of clean water” as the metric of analysis does not capture differences in the water quantity, reliability and ease of access.
  • There could be multiple important outcomes not captured in our analysis.
  • Evidence Action may be spending additional money in order to serve harder-to-reach and/or particularly valuable populations.
  • In the absence of better data, we assume uniform counterfactual rates for programs, at the risk of masking variation across nonprofits.
  • Our estimates rely on data made public by Evidence Action on its website, annual reports, financial statements and Form 990s.
  • We only analyze programs that meet our criteria. As a result, this report may not fully reflect the impact of Evidence Action.
  • We do not assess what explains the nonprofit's cost-effectiveness.

We assign a rating to the nonprofit using the rubric:

  • There are indications of governance or financial health issues at the nonprofit.

  • After being given an opportunity, the nonprofit chose not to publish impact information.

    We are not yet issuing this level of star rating.

  • The rated program does not meet our benchmark for cost-effectiveness.

  • The rated program is cost-effective.

  • The rated program is highly cost-effective.

Read More

Nonprofit Comment

Not provided. This may be because we lacked contact information for Evidence Action or it chose not to comment. If you are a representative of this nonprofit, contact us to review and comment on your rating.

Before publishing, we ask every nonprofit we can to review our work, offer corrections and provide a comment.

Analysis Details

Analysis conducted by ImpactMatters and published on November 22, 2019.

An ImpactMatters analyst searched the Form 990s, annual reports, audited financials and the website of Evidence Action to calculate impact and rate cost-effectiveness. A second analyst conducted quality control.

We welcome corrections. If you are interested in exploring applications of ImpactMatters data, contact us at

Governance Check

Evidence Action passes our governance check.

Conducted a financial audit

Overhead spending is reasonable (<35% of total spending)

Charity Navigator has not issued a fraud or mismanagement advisory

Evidence Action itself has not reported any material diversions of assets

Evidence Action itself has not reported any excess benefit transactions

Source: Evidence Action Form 990 and Charity Navigator

How We Calculate Impact

This rating is based on ImpactMatters analysis of the impact of Dispensers for Safe Water relative to costs. Impact is the change in the social outcomes of people served by the program, net of the change that would have happened even without the program (the “counterfactual”); divided by cost. Learn more.

For Donors

A guide to our process for analyzing nonprofits and assigning ratings.

For Nonprofits

Learn about best practices for reporting impact for different program types.

For Researchers

Our collected guidelines on how we analyze impact of nonprofit programs.

Rating is a complex exercise and we urge you to read our frequently asked questions for details of how and why we issue these ratings.