On average, each person uses about 80-100 gallons of water a day. While many people don’t give the quality of their water much thought, the crisis in Flint, Michigan brought the issue of water contamination and filtration into the national headlines. According to one study, as many as 45 million Americans in any given year from between 1982 and 2015 may have been exposed to drinking water that did not meet the standards of the 1974 Safe Drinking Water Act.

While there’s no denying that many states struggle to deliver clean water to all of their residents, especially in impoverished and rural areas, the fact remains that, on the whole, water departments throughout the country do a good job of keeping drinking water safe. Some homeowners, however, prefer to have the added protection of installing a water filtration system in their homes. These systems treat water coming into the house to remove whatever impurities or contaminants it may have picked up in the pipes.

How Do Water Filters Work?

Water filtration is the most important part of any water treatment process. The primary purpose of filtering is to physically remove contaminants from drinking water. This is accomplished by passing the water through a screen-like object called a water filter media. The media can be composed of almost any material, as long as it has the capability to allow water to pass while stopping solids from moving through. 

All solids in the water are blocked by the presence of this filter media. When they come into contact with the filter, these materials become entrapped and collide with one another. A filter’s performance is measured by the size of the space between the media, which is referred to as the pore size. The smaller the pore size, the more substances that are removed from the water. Smaller pore sizes also decrease the rate and the volume at which water can be filtered.

Types of Water Filtration

There are a number of different filtration systems that can be installed in a home, each one using a slightly different filter media and filtering process. Here are a few types of water filtration systems available:

• Charcoal Filters: The most common type of water filters today utilize charcoal or “activated charcoal.” Mostly comprised of carbon, charcoal is the residue of partially burned organic material. When chemical processing or specialized heating is introduced to charcoal, it becomes more porous; this is known as activated charcoal. Charcoal filters operate primarily on the principle of absorption. Large quantities of gases, which can also include poisonous ones, adhere to the residue. Because of its wide surface area and porous nature, charcoal is able to absorb most of the impurities in typical drinking water. These filters are also capable of absorbing organic pollutants that tend to cause bad odor and taste. While charcoal filters are usually incorporated into household solutions, they can also be used in smaller filtration units installed on individual faucets.

• Reverse Osmosis Filtration System: This process forces water through an ultra-thin, semi-permeable membrane, where it divides the tap water into pure liquid and a concentrate containing impurities. The liquid is saved to a storage tank for future use, while the concentrate trapped in the membrane is diverted down the drain. Purified water stored in the tank is then subjected to an activated charcoal filtration process to rid it of all lingering tastes and odors before the water is dispensed in the household. Reverse osmosis systems are very effective at reducing the level of pesticides, petrochemicals, and chloroform in drinking water. 

• Ion Exchange Water Filters: Designed to remove dissolved minerals from the water, ion exchange filters were originally used in boilers and other industrial applications before being adapted for home purifying units. These household units combine the original ion exchange system with carbon-based filtration. The water filtering through is softened by interchanging natural-forming ions in the water with its own ions. This removes minerals such as magnesium, calcium, and fluorides from the water to further nullify the dangerous effect of scale accumulation.

• Ultraviolet (UV) Filtration Systems: An exception to the rule of passing water through a filter media, UV filters work by eliminating bacteria and pathogens in water with UV rays. Known to be environmentally friendly, this method also conserves the most water without using any chemicals. UV systems destroy bacteria without adding any taste or odor to the water, unlike chemical disinfectants that may be added when dangerous pathogens, like E. coli, are suspected to be present. UV filtration systems aren’t enough to purify water on its own since it prioritizes destroying bacteria and viruses instead of filtering minerals and other contaminants. As such, they are usually paired with one of the other filtration methods.

• Distillation Water Filtration System: Extremely efficient and reliable, distillation is generally regarded as the most effective method for removing contaminants from water. Distillation is simply the process of heating water to produce steam, which burns away impurities. The steam then cools off and condenses to form completely pure water droplets that are then placed in a container for later use. Distillation produces 99.9% contaminant-free water when combined with carbon filtration, which eliminates bacteria, sodium, heavy metals, and nitrates.

While most municipal water supplies and wells deliver clean drinking water to households, some people like to have the extra peace of mind that a water filter can provide. While none of them can remove ALL contaminants from the water on their own, they can be combined in a variety of ways to form a more comprehensive solution. 

Most of these systems are rather expensive to install and take quite a lot of effort to maintain, however. Without regular maintenance, they can even cause significant damage to household plumbing. For more information about what kind of filtration systems are viable solutions for a home, contact a plumbing professional.