Choosing the Right Water Filtration System
Understanding water filtration systems and processes
These charts show some common types of water filtration systems and processes. To learn if there is lead in your water supply you can purchase a water testing kit from Healthy Babies, Bright Futures. To test your water for various chemicals and bacteria, contact your local health department or follow the EPA’s home water testing guide.
|
Filtration Technology |
Filtration Process |
Type of System |
Benefits |
Costs |
|---|---|---|---|---|
|
Activated Carbon and Granulated Activated Carbon |
Contaminants are removed through adsorption, where contaminants are attracted to the surface of the activated carbon and held to it |
Pitcher, Faucet, Counter, Under-Sink, Whole House |
Removes or reduces lead and arsenic; improves taste and odor of water; low upfront cost and no installation cost; portable |
Price and installation costs for systems go up with size; smaller systems need more filter changes |
|
Reverse Osmosis |
Semipermeable membrane that blocks particles larger than water molecules |
Counter, Under-Sink, Whole House |
Removes most unwanted contaminants including lead, arsenic and perchlorates |
The filtration process wastes water; removes good minerals along with contaminants; cost of system goes up with size, filter quality |
|
Distillation |
This filter process heats water to vaporize it and then condenses the steam back into water |
Counter, Floor |
Removes chemicals that have higher boiling points than water - lead, arsenic, heavy metals, fluorides and bacteria |
Energy inefficient; systems can be large and expensive; removes good minerals along with contaminants |
|
Ultraviolet (UV) |
Uses ultraviolet light to kill bacteria and other microorganisms |
Whole House, Portable |
Does not use heat or chemicals to remove contaminants; low maintenance |
Cannot remove chemical contaminants and works best in addition to other filtration; sensitive to discoloration in water |
Choosing a Water Filter
Once you’ve decided on the type of water filtration system and the process you need to protect your family from contaminants in the water supply, knowing if a product is certified also is important. If a product carries a certification, it means that a third-party tester has verified that it screens for the chemicals and contaminants it claims to filter.
The two certification bodies are NSF International (NSF) and the Water Quality Association (WQA). The state of California also maintains a list of water filtration systems that have been certified to screen arsenic.