Why clean water reduces CO₂ emissions

A household uses a water filter system that provides clean drinking water without the need to boil it.

Before the project, the household boiled water daily using a traditional fire, consuming around 1 tonne of wood per yearfor this purpose. Burning this amount of wood produces significant CO₂ emissions. A commonly used emission factor is 1.83 tonnes of CO₂ per tonne of wood.

With the water treatment technology, boiling is no longer necessary. The entire amount of fuel previously used for boiling can therefore be considered as avoided.

The CO₂ savings are calculated as follows:

1 tonne of wood avoided
×
1.83 t CO₂ per tonne of wood
=
1.83 t CO₂ savings per household per year

This amount is verified, confirmed, and issued as 1.83 CO₂ certificates — always one certificate per avoided tonne of CO₂.

Note: This example illustrates the principle of CO₂ reduction in clean water projects. Whether a project can generate certificates depends on strict rules: recognised standards (e.g., Gold Standard, VCS), detailed baseline studies on fuel consumption, independent audits and ongoing monitoring. Not every water filtration or purification solution is automatically eligible for certification.

For the emission reductions from clean water projects to be issued as CO₂ certificates, they must meet strict requirements. The savings must be additional (without the project, fuel would still be used for boiling), measurable, verifiable, and auditable. International standards such as Gold Standard or Verra (VCS) define these criteria.

These standards specify in detail how fuel consumption before and after the introduction of the water treatment technology must be calculated, and which data a project must report on a regular basis — such as usage rates, reductions in fuel consumption, emission factors or potential leakage effects. Independent auditors verify on site whether the technology is actually being used and whether the documented savings are plausible and robust.

Only when all evidence is complete and confirmed can a CO₂ certificate be issued — always representing exactly one tonne of CO₂ avoided.

This creates a transparent process that ensures each certificate reflects a real and verified climate impact.

Not all water-related projects are suitable for generating CO₂ certificates. The key requirement is that the project must demonstrably replace the need to boil water and thereby reduce fuel consumption. Without this link, no measurable emission reductions occur. The following project types cannot be certified:

Wells and handpumps
They improve access to water but do not automatically replace boiling. Many of these water sources are not microbiologically safe enough to be used without additional treatment.

Rainwater harvesting systems
Although they improve water availability, they rarely provide pathogen-free drinking water. Without full microbial safety, boiling remains necessary — and no CO₂ savings occur.

Piped water systems and infrastructure projects
Pipes, tanks and distribution networks transport water but do not improve its quality. If the water is not safe to drink, boiling is still required.

Desalination systems without an energy-efficiency component
They provide clean water but often require significant amounts of energy. No fuel savings occur — and in some cases, emissions may even increase.

Awareness campaigns or training alone
Educational activities are important but do not directly reduce fuel use or emissions in a measurable way.

Conclusion:
Only technologies that demonstrably replace boiling can generate CO₂ certificates. If boiling remains necessary, no quantifiable emission reductions exist — and therefore no certificates can be issued.

To ensure that the CO₂ savings of a clean water project are reliable, they are monitored on a regular basis. Project operators collect data on the actual use of the water treatment technology, the resulting reduction in fuel consumption, and the conditions under which water was previously boiled. These requirements are clearly defined and follow recognised methodological guidelines.

Independent auditors verify this data on site and compare it with the criteria of international standards such as Gold Standard or Verra (VCS). They check whether the technologies are used correctly, whether boiling is truly avoided, and whether the reported savings are traceable and robust.

Only when all evidence is complete and plausible is the confirmed CO₂ reduction documented and approved for the issuance of certificates.

This creates a transparent process that ensures each certificate represents a real and verified climate impact.