Approach · Safe water
Water chlorination
Adding chlorine to drinking water at the source or in the pipes, so it is safe to drink.
How strong is the evidence?
Not yet rated
The evaluator hasn't published an evidence rating we can quote.
Published figures for charities doing this
| Charity | Figure | Source |
|---|---|---|
| GiveWell All Grants FundGiveWell's funding bar | 6× as cost-effective as GiveWell's benchmarkas of May 2026 | GiveWell (opens in a new tab) |
Modeled, not guaranteed. Figures in different units measure different kinds of good and should not be compared directly.
Charities doing this work
GiveWell All Grants Fund
GiveWell's broader fund. It can grant to any program that meets GiveWell's cost-effectiveness bar, including newer and higher-risk opportunities.
6× as cost-effective as GiveWell's benchmark
GiveWell, as of May 2026
Evidence Action
Runs several programs backed by strong evidence, including safe water, deworming and nutrition. A longstanding GiveWell grantee.
Not yet rated
No published figure we can quote
Uduma
A water organization. GiveWell funded a pilot of in-line chlorination, which adds chlorine to piped water.
Not yet rated
No published figure we can quote
Sources
Questions donors ask
- Does water chlorination work?
No evaluator has published an evidence rating for this approach that we can quote. See the sources on this page for the full reasoning.
- How cost-effective is it?
It depends on the charity and the setting. The table on this page lists each published figure with its source. All are modeled, not guaranteed.