Home water filtration bottles and systems can purify H2O and make it a little safer for drinking.

© Chris Brignell | Dreamstime.com

More and more people are concerned that tap water isn’t safe so they’re choosing instead to purchase bottled water, believing it has been through “water filtration” and is therefore safer to drink. Maybe. Water filtration isn’t a cut-and-dried process, and bottled water isn’t necessarily the safest choice.

Many methods of water filtration, or water purification, are available, although at the basic level they’re either a water filter—like the faucet attachment often seen in homes—or a chemical treatment process, such as those used at the municipal level, usually in combination with a filtering process.

Municipal water supplies are treated to uphold the Safe Water Drinking Act standards that are set and monitored by the Environmental Protection Agency (EPA). The tap-water standards are even higher than the ones the EPA set for bottled water (see Is Bottled Water Safe?).

Water Filtration: What Goes Into It?

The Centers for Disease Control and Prevention (CDC) states that most municipalities use these steps in their water-filtration process:

1. Coagulation and flocculation: Chemicals with a positive charge are added to the water. The positive charge neutralizes the negative charge of dirt and other dissolved particles in the water. When this occurs, the particles bind with the chemicals and form larger particles, called floc.
2. Sedimentation: During sedimentation, floc settles to the bottom of the water supply, due to its weight.
3. Filtration: After sedimentation, the clear water is sent through filters of varying compositions (sand, gravel, and charcoal) and pore sizes in order to remove dissolved particles, such as dust, parasites, bacteria, viruses, and chemicals.
4. Disinfection: A disinfectant (for example, chlorine or chloramine) may be added in order to kill any remaining parasites, bacteria, and viruses, and to protect the water from germs when it is piped to homes and businesses.

According to ScienceDaily.com, substances removed during the water filtration process include parasites such as giardia or cryptosporidium, bacteria, algae, viruses, fungi, minerals (including toxic metals such as lead or copper), and man-made chemical pollutants.

(In my home, we sometimes smell chlorine when we run water from our faucet, which makes me wonder what was in the water we were drinking the day before. Shouldn’t they be required to announce these findings? Apparently not. According to Womenhealthmag.com, “Sometimes residents aren’t immediately told when issues are found.” That’s a little unsettling.)

You can find out what your municipal water-filtration organization may be dealing with if you go to the Environmental Working Group’s website and plug in your zip code. (Author’s note: I used my zip code and found that from 2010 to 2015, on average, seven cancer-causing contaminants and 16 other contaminants exceeded regulations. Bring on that chlorine!)

Water-Filtration Home Improvements

Even though the EPA’s guidelines for public drinking water are good, the CDC advises, we still may want to use a home water-filtration system to remove other contaminants—especially if a family member has a compromised immune system and/or we want to improve the taste of our drinking water.
You can use a point-of-entry system, which is a water-filtration system installed on the main water line coming into your house. It then filters all the water before it goes into your pipes. This may work well, but there still may be a question of pipe contaminants (not that it’s easy to determine).

“We do not currently have pipes that are 100 percent safe,” according to Healthybuildingsciences.com. “As a result, we must choose the best options available. After reviewing the research for plastic vs. copper, copper piping appears to be the system that is the easiest to control. Water filtration methods as well as new lead standards help ameliorate heavy metal toxicity risk. We do not have enough information on the dangers of plastic piping. Studies have shown alarming evidence of VOC presence, unknown contaminants in drinking water, and Assimilable Organic Compounds that can lead to deleterious bacteria. There are too many question marks to adequately enact safety precautions, and therefore plastic piping cannot be fully trusted.”

The simplest and least expensive method of water filtration is a point-of-use system—a water-filtration device placed on the faucet or under a sink (usually the kitchen sink). But you need to remember to regularly replace the filter, and always draw your drinking and cooking water from this one source. Of course, a water-treatment company will be happy to sell you both these systems.

Water-Filtration Decisions

Simple procedures such as boiling water or using a household charcoal filter are not sufficient for treating water from an unknown source, according to ScienceDaily.com. This might also be a concern with well water, which should be tested regularly. “Even natural spring water—considered safe for all practical purposes in the 1800s—must now be tested before determining what kind of treatment is needed,” says ScienceDaily.

That doesn’t mean, however, that water filtration at home is an absolute necessity if your water is coming from a municipal source.

“In general, we have an amazing system of tap water in the United States,” says Dr. Hilary Arnold Godwin, a professor in the Department of Environmental Health Sciences and Associate Dean at the UCLA Fielding School of Public Health. “The municipal districts treat the water at the plant to meet high Federal guidelines that have very strict limits on lead. There are also very stringent reporting, prevention, testing, and remediation requirements.”