Water treatment is the process of improving water quality to make it safer, cleaner and more suitable for its intended use — whether for drinking, cleaning, bathing or otherwise. This can involve addressing a broad range of water quality issues, including hardness, chemicals, sediment, microorganisms and more, while also addressing aesthetic concerns such as taste, odor or discoloration.
Proactive home water treatment is especially important for private wells, since they aren’t regulated by public agencies. But even treated municipal water can encounter issues as it travels through aging infrastructure, or through the presence of unregulated contaminants.
In this guide, we’ll explain how home water treatment works, why it’s essential and how Culligan can help you take control of your home’s water quality.
What Counts as Water Treatment?
Water treatment can look very different depending on where your water comes from. Municipal water supplies undergo treatment at public facilities before reaching homes, while private well water requires treatment entirely at the household level. Both approaches aim to make water safer, cleaner and more suitable for everyday use, but the steps involved vary.
Municipal Treatment
Public water systems treat water through a series of steps to meet strict guidelines, according to the U.S. Centers for Disease Control and Prevention (CDC). These steps typically include:
- Coagulation: Water treatment plants add chemicals, such as salts, aluminum or iron, to bind small suspended particles together.
- Flocculation: The water is gently mixed to further bind particles together into floc, which are easier to remove in later steps.
- Sedimentation: The larger floc particles settle at the bottom of a treatment tank, separating from the clearer water above.
- Filtration: Water passes through layers of sand, gravel, activated carbon and sometimes reverse osmosis (RO) filters to reduce any particles, contaminants and some chemicals.
- Disinfection: Treatment facilities often use a combination of chlorine, chloramine and/or ultraviolet light to kill harmful microorganisms.
These processes help municipal water meet safety standards established by the U.S. Environmental Protection Agency (EPA) and Health Canada.
That said, water can still pick up contaminants after it leaves the treatment facility — for example, from aging infrastructure, lead service lines or plumbing. For this reason, many homeowners add household filtration or softening systems as a second layer of protection.
Well Water Treatment
Private wells don’t benefit from municipal treatment. Instead, all water quality management happens at the household level. Because private wells are not federally regulated, well owners are responsible for testing and treating their own water supply.
Treatment often includes a combination of technologies, such as whole-house filtration, reverse osmosis, UV disinfection or water softening, depending on what testing reveals. Because conditions vary so much, a professional water test is the best first step in identifying the right well water treatment approach.
Worried about your well water?
What Is Water Filtration?
Filtration is one of the most essential water treatment methods used both at the municipal and household levels. It works by physically or chemically removing particles, chemicals and contaminants from water, improving the water quality for drinking water, cleaning, bathing and other uses.
For households using city water, water filtration focuses on addressing residual contaminants that may remain in or re-enter the water supply after leaving the treatment plant — including those from aging pipes, household plumbing or groundwater sources. It can also cover water quality issues that aren’t yet regulated, or contaminants that may be present but in lower amounts than regulations require.
Common systems include:
- Whole-house filters: Installed at its point of entry, these systems treat all the water entering a home. Depending on the filtration media used, they can reduce sediment, chlorine, sulfur, iron and even contaminants like arsenic, nitrate or forever chemicals (PFAS). As a result, every tap and appliance receives cleaner, safer water.
- Point-of-use filters: These are installed where water is consumed, such as at a kitchen sink. Capabilities vary: pitcher or faucet filters mainly improve taste and odor, while under-sink systems like reverse osmosis can reduce a broad range of contaminants such as lead, arsenic, PFAS, nitrates and other dissolved contaminants when certified to do so.
- Specialized filtration: Options like UV disinfection and advanced carbon filtration can help neutralize microorganisms or chemicals not addressed by basic methods.
- Activated carbon filters: These systems use highly porous carbon to attract and trap particles and chemicals like chlorine, volatile organic compounds (VOCs) and some pesticides. This improves both safety and taste by addressing odor and disinfection byproducts. Carbon filtration also can be part of other methods such as reverse osmosis.
- Reverse osmosis systems: This point-of-use filtration approach forces water through a semipermeable membrane to address a wide range of contaminants, including lead, PFAS chemicals, arsenic, nitrates and dissolved solids. Culligan’s Aquasential® Reverse Osmosis Drinking Water System combines RO with additional stages for thorough water filtration and better taste and is certified to reduce more than 90 contaminants.
Explore water filtration solutions.
What is Water Softening?
Water softening is a specialized treatment process that addresses hard water (water containing high levels of calcium and magnesium) through ion exchange. While these minerals don’t typically pose direct health risks, they can cause a range of aesthetic and household challenges, including:
- Scale buildup in pipes and appliances
- Reduced soap and detergent effectiveness
- Dry skin and hair irritation
- Stiff, scratchy laundry
- Shortened lifespan of water-using appliances
The water softening process uses negatively charged resin beads to attract the positively charged calcium and magnesium ions, removing them from your water supply before it flows through your home.. As a result, the water quality improves for everyday use and prevents damage to you and your home.
How Is Municipal Water Treatment Regulated?
The water treatment process is guided by regulations that set safety standards for drinking water quality.
In the United States, the EPA oversees the National Primary Drinking Water Regulations, which establish legally enforceable limits for more than 90 contaminants, including microorganisms, disinfectants, disinfection byproducts, chemicals and radionuclides.
In Canada, Health Canada provides the Guidelines for Canadian Drinking Water Quality, which serve as the basis for enforceable standards set by individual provinces and territories.
While these guidelines are designed to provide safe drinking water, there are important limitations to keep in mind:
- Private wells are not regulated: Neither the EPA nor Health Canada directly regulates private well water. Well owners are responsible for testing and maintaining their own water quality.
- Water quality can change after treatment: Even if water meets regulatory standards at the treatment plant, it may accumulate new contaminants as it travels through aging pipes or household plumbing. For example, lead can leach into drinking water from older service lines or plumbing fixtures.
- Emerging contaminants may not be covered: Some substances, including certain pharmaceuticals, PFAS chemicals and disinfection byproducts, are still undergoing scientific review or have limited or not-yet-implemented regulation. While Health Canada and the EPA have proposed new rules for PFAS maximum contaminant levels, it will take years for these to become fully enforceable across all water supplies.
- Aesthetic concerns aren’t always regulated: Issues like taste, odor and discoloration are often categorized under secondary water quality standards, which are not legally enforceable but may still impact the household and drinking experience.
For these reasons, even residents connected to municipal water treatment plants may choose to implement home water filtration or softening solutions. These systems provide an extra safeguard by addressing both regulated and unregulated contaminants, as well as aesthetic issues that affect water quality.
Culligan offers personalized solutions based on your home’s water supply and water quality. A free in-home water test and consultation can help determine your water hardness level and recommend the right water treatment system for your needs.
Schedule your free water test.
Water Treatment FAQs
Does Water Treatment Change Depending on the Source?
Yes. Water treatment processes vary depending on whether the water supply comes from groundwater, surface water (like rivers or lakes) or raw water from wells.
- Groundwater typically contains dissolved minerals that may require water softening and filtration to address water hardness, iron or sulfur.
- Surface water sources often have higher levels of sedimentation, organic matter and potential pollutants, which call for coagulation, flocculation, filtration and disinfection.
- Raw water from private wells can introduce unique challenges, including contaminants like nitrates, arsenic or microorganisms, especially without municipal treatment plant protections.
A customized approach to household treatment helps ensure safer drinking water, protects appliances and supports overall water quality.
Can I Test My Own Water for Contaminants?
Yes, but with limitations. At-home test kits can offer quick readings for basic concerns like hardness, pH or chlorine, but they often fall short in two ways. First, many kits are difficult to interpret. Even if you get a reading, it may not be clear what it means for your water quality or what steps to take next. Second, most standard kits don’t test for a broad range of possible issues, which means you could be left with unanswered questions.
Culligan does offer a home PFAS test kit for homeowners concerned about these contaminants. But for the majority of concerns, Culligan recommends professional, in-home testing. A free in-home water consultation provides on-the-spot results for common water problems, explained by a trained specialist. For more complex concerns, samples can also be sent to a certified lab for detailed analysis.
This approach gives you both accurate results and clear next steps, ensuring any water treatment recommendation is matched to your home’s actual water quality.
How Do I Maintain a Water Treatment System?
Water treatment systems require regular maintenance to remain effective. Maintenance needs vary by system type:
- Filtration systems, including whole-house filters and RO units, require periodic filter or media replacements to maintain flow rate and contaminant effectiveness.
- Water softeners need salt refills and occasional resin bed maintenance.
- Disinfection or UV treatment systems may require bulb replacements and cleaning to ensure performance.
Most manufacturers provide maintenance schedules, but professional servicing — often available through water treatment providers like Culligan — can help extend system life and maintain water safety.
H2: Home Water Treatment Made Simple
Whether your water source is a municipal supply, private well or surface water, understanding your water treatment system needs starts with identifying what’s in your water.
A free in-home water test analyzes your water’s unique profile, including hardness levels, total dissolved solids (TDS), pH, iron and other impurities. For well owners, this step is critical, as water filtration safeguards against unregulated risks. Ready to get started? Schedule your free consultation today.
*Contaminants may not be present in your water.