Health
The Complete Guide to Water Filtration: Why You Need a Water Filter in 2025
January 21, 2025
71% of Americans drink tap water at least sometimes, if not regularly (1). If we don’t drink it, we at least use it for bathing, laundry, and cleaning. The majority of Americans also worry about their water quality. A recent Gallup poll shows that the U.S. population is more concerned about water quality than it has been since 2017, with 63% of Americans reporting that they “worry a great deal” about polluted drinking water (2).
But what's really flowing from your tap?
While municipal water treatment has made waterborne diseases rare in developed countries, research shows that nearly half of the tap water in the US still contains various contaminants including chlorine, heavy metals, microplastics, and harmful “forever chemicals” (3). Drinking these over a prolonged period of time can lead to health issues including gastrointestinal issues, nervous system disorders, reproductive health concerns, and more (4).
In this comprehensive guide, we'll explore what filtered water is, what a water filter does, and why filtered water is good for you.
Before we dive into why filtered water is good for you, let's explore what might be lurking in your unfiltered tap water. Recent studies have identified several categories of contaminants that could be present in your drinking water, each with its own potential impacts on health and water quality (3).
Physical Contaminants
Physical contaminants are the most visible category of water impurities. These include sediment, organic material, small pieces of degrading pipes, and rust particles. Their presence can affect water's appearance and taste. More importantly, they can indicate underlying infrastructure problems that need attention.
Chemical Contaminants
Chemical contaminants are perhaps the most concerning category. Research has identified several common chemicals in tap water:
Chlorine and Chloramines
Chlorine is a disinfectant used to kill germs/bacteria in water while chloramines are a group of chemical compounds that contain chlorine and ammonia. The type of chloramine used to kill germs/bacteria in drinking water is called monochloramine.
While they're commonly used for municipal water treatment, chlorine and chloramines can (5):
- Create potentially harmful disinfection byproducts
- Cause an unpleasant taste and smell
- Irritate sensitive skin and eyes
- Potentially damage beneficial gut bacteria
They're also responsible for that distinctive "pool water" smell and taste that many people (including myself) find unpleasant.
Native Note: Chloramine in water can contaminate the dialysis fluid and enter the blood of a dialysis patient. Once it enters the bloodstream, chloramines can also alter hemoglobin and cause acute hemolytic anemia and has even led to two epidemics in dialyzed uremic patients (6).
Heavy Metals
Common heavy metals found in tap water include:
- Lead (from old pipes and fixtures)
- Copper (from plumbing)
- Mercury (from industrial pollution)
- Arsenic (naturally occurring in some regions)
A 2023 Environmental Working Group study found that even low levels of these metals, when consumed over time, may contribute to health issues including lung and kidney damage, cognitive impairment, fatigue, and gastrointestinal distress (7).
Pharmaceutical Residues
Modern water treatment plants weren't designed to remove medications that enter the water supply through human excretion. Trace amounts of various drugs have been detected in tap water, including (8):
- Pain relievers
- Antibiotics
- Hormones
- Antidepressants
While the concentrations are low, the long-term effects of chronic exposure to these compounds remain poorly understood.
Biological Contaminants
While municipal water treatment is generally effective at eliminating harmful bacteria, some microorganisms have evolved to resist standard treatment methods. For example, cryptosporidium—a parasite that causes diarrhea—can survive chlorine treatment (9).
Other potential biological contaminants include Giardia cysts, various bacteria strains, and viruses. These organisms pose particular risks for individuals with compromised immune systems.
Emerging Contaminants
Scientists are increasingly concerned about newly identified contaminants in our water supply. Microplastics have become ubiquitous in water sources worldwide, with uncertain health implications.
PFAS, often called "forever chemicals," persist in the environment and are linked to various health concerns (3). Pesticide residues and industrial chemicals continue to enter our water systems through runoff and industrial processes.
What Is Filtered Water? Understanding the Basics
Filtered water is tap water that has been processed through one or more filtration methods to remove impurities and contaminants. Think of a water filter as a security guard for your drinking water—it stops unwanted guests (contaminants) while letting the good stuff through.
So, what does a water filter do exactly? At its core, water filtration employs various physical (or chemical) processes to create cleaner, better-tasting water. These processes work together to remove harmful contaminants, reduce unpleasant tastes and odors, improve water clarity, and maintain beneficial minerals that your body needs.
Is Buying a Water Filter Worth It? The Health Benefits of Filtered Water
Research suggests that filtered water offers several potential health benefits:
Reduces Exposure to Harmful Substances
Filtering your water can significantly reduce exposure to:
- Heavy metals that can accumulate in your body
- Chlorine byproducts linked to various health concerns
- Emerging contaminants with unknown long-term effects
Improves Taste and Smell
Filtered water typically tastes and smells better because it removes:
- Chlorine and chloramines
- Sulfur compounds
- Organic matter
- Dissolved metals that can create metallic tastes
Better Hydration
Protection for Sensitive Individuals
Filtered water is particularly important for:
- Infants and young children
- Pregnant women
- Elderly individuals
- People with compromised immune systems
- Those with chemical sensitivities
If you're considering a water filter, start by understanding your specific needs. Getting your water tested can help identify any particular contaminants you should target. Different filtration systems address different concerns, so matching the right technology to your situation is important (12).
When making your choice, consider factors like flow rate, capacity needs, and maintenance requirements. Look for systems with proper certifications (like NSF/ANSI ratings) to ensure they meet quality standards (12).
The Bottom Line
While tap water in developed countries is generally safe to drink, installing a water filter provides an extra layer of protection against various contaminants. Understanding what filtered water is, what a water filter does, and why filtered water is good for you can help you make informed decisions about your drinking water.
The best water filter for your home depends on your specific needs, local water quality, and budget. Regular maintenance ensures your chosen system continues to provide clean, great-tasting water for you and your family.
Remember: clean water isn't just about safety—it's about optimal health, better taste, and peace of mind. Consider a water filter as an investment in your family's health and well-being.
Kat Kennedy
Kat Kennedy
Medical Disclaimer
This content is for informational and educational purposes only. It is not intended to provide medical advice or to take the place of such advice or treatment from a personal physician. All readers/viewers of this content are advised to consult their doctors or qualified health professionals regarding specific health questions. Neither Dr. Chad Walding nor the publisher of this content takes responsibility for possible health consequences of any person or persons reading or following the information in this educational content. All viewers of this content, especially those taking prescription or over-the-counter medications, should consult their physicians before beginning any nutrition, supplement, or lifestyle program.
