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.