Carbon Emission Reductions

Households that use a Tunsai ceramic water purifier (CWP) typically reduce or eliminate boiling water for drinking.  Less boiling means less use of non-renewable wood and charcoal, which are the main sources of energy for cooking in rural Cambodia.  By reducing the need for fuel wood and charcoal, each CWP reduces the stress on local forest resources and reduces greenhouse gas emissions.

Hydrologic registered the production and dissemination of the CWP in Cambodia as a carbon project with the Gold Standard in August 2012. For further information about Hydrologic’s Carbon Finance Project: Production and Dissemination of Ceramic Water Purifiers by Hydrologic in the Kingdom of Cambodia – GS1020. Please visit the Gold Standard Project Registry.

Hydrologic is currently renewing the Carbon Finance project for another 7-year term. Click “GOLD STANDARD PASSPORT“, “GOLD STANDARD LOCAL STAKEHOLDER CONSULTATION REPORT“, “PROJECT DESIGN DOCUMENT” to download the reports.

Hydrologic welcomes your feedback. If you have any comments or questions relating to the project please contact:
Mr. Im Bora, Carbon Project Manager
Telephone: +855 (0) 23 6911 981

For enquiries relating to the purchase of Hydrologic’s carbon offsets please contact:
Ms. Maiwenn Altermatt, Hydrologic CEO
Telephone: +855 (0) 12 421 389


Hydrologic’s products are built around Ceramic Water Purifiers (CWPs), which have set the standard for cost-effective water treatment in developing countries for the past 30 years.

Small-scale ceramic filtration has a long history, having been used in various forms since antiquity. Locally produced ceramic pot-style filters have the advantages of being relatively inexpensive, chemical free, low-maintenance, portable, effective, and easy to use. The filters remove microorganisms from water by gravity filtration through porous ceramics, with typical flow rates of 2-3 liters per hour.

Research has found that the filters significantly improve household water quality, eliminating up to 99.99% of E. coli. In a comprehensive UNICEF study, households using a CWP reported only half as many cases of diarrhea as matched control households without a filter.

Since Hydrologic’s filters are enclosed in food-grade plastic containers, they ensure that treated water is safely and properly stored. Water treated by other methods in Cambodia (by boiling, for instance) is often kept in open containers and is easily re-infected. Hydrologic filters dispense water from a tap, increasing their effectiveness and ease of use.

Hydrologic’s filters have only one moving part (the tap) and need no external energy source (such as UV lamps) or consumables (i.e. chlorine packets). Unlike cholrine-based disinfection, CWP filtration produces no significant taste issues with water.

CWPs can become clogged if they are being used to treat particularly turbid water. In order to avoid clogging , Hydrologic recommends that extra turbid water be allowed to settle for a day or so in a storage container prior to filtration. Hydrologic’s filters can easily be removed for periodic cleaning, giving families the power to considerably extend the useful life of their filters.

Household-scale ceramic filtration technology is considered among the most promising options for treating drinking water at the household level in developing countries. Its use in Cambodia is widespread and growing, with the involvement of local and international NGOs and government efforts that have been supported by UNICEF, WSP-Cambodia, and others.