POU systems can be installed in various places in the home, including on the counter top, at the faucet itself, or under the sink. POE systems are installed where the water line enters the house. POU and POE devices are based on various contaminant removal technologies. Filtration, ion exchange, reverse osmosis, and distillation are some of the treatment methods used. All types of units are generally available from retailers, or by mail order.
Prices can range well into the hundreds of dollars.
Depending on the method and location of installation, plumbing changes can also add to costs. Home filtration units use activated carbon filters, which adsorb organic contaminants and constituents that cause taste and odor problems. Depending on their design, some units can remove chlorination by-products, some cleaning solvents, and pesticides. To maintain the effectiveness of these units, the carbon canisters must be replaced periodically. Activated carbon filters are not efficient in removing metals such as lead and copper.