Devices for filtering drinking water are installed on or under the kitchen sink.

They make it possible to achieve affordable drinking water filtration and are commonly used in a house or apartment for a family. Most water purifiers use granular or block activated carbon and resins to more or less trap health-damaging contaminants. These filters are effective at improving the taste and odor of water, and many are also designed to reduce specific contaminants such as lead, nitrates, heavy metals and other contaminants. An activated carbon filter is not designed to eliminate all pathogenic organisms. Charcoal filters have a specified shelf life and should be replaced regularly according to the manufacturer's instructions.

Each model of under-sink purifier provides a solution depending on the quality of the water.

These water filters are effective in improving, in addition to the taste and odor of tap water, certain pathogenic elements, such as protozoan cysts along with chlorine. It is possible to add at the end of the filtration, a microfiltration at 0.2 micron, to neutralize certain bacteria.