Chlorine and chloramine are widely used by public water systems to disinfect drinking water and maintain a residual as treated water travels through distribution pipes. For many households, the practical question is whether they want to reduce the resulting taste or odor—and whether their water uses chlorine or chloramine.
This guide explains how the two disinfectants differ, how EPA regulates them, which treatment approaches are commonly used, and how current Phoenix Gravity testing applies to Berkey® owners.
Why Is Chlorine Used in Drinking Water?
Chlorination has been used in U.S. public drinking-water treatment for more than a century. One of chlorine's key roles is to leave a residual disinfectant that continues to work as treated water moves through the distribution system.
Chlorine can also affect taste and odor at the tap. Some people notice a swimming-pool-like smell or a sharper treated-water taste depending on utility operations, water temperature, and where the home sits within the distribution system.
Why Some Water Systems Use Chloramine
Chloramine is most commonly formed when ammonia is added to chlorine. Utilities may use it because it lasts longer in distribution systems than free chlorine.
That same persistence also means chloramine can be harder to reduce. A basic carbon filter that performs well for chlorine should not automatically be assumed to provide the same chloramine performance.
How Much Chlorine or Chloramine Is Allowed?
EPA regulates residual disinfectants using Maximum Residual Disinfectant Levels (MRDLs). The federal MRDL is 4.0 mg/L as Cl₂ for chlorine and 4.0 mg/L as Cl₂ for chloramine. Chlorine dioxide has a separate MRDL of 0.8 mg/L.
A single household reading should not automatically be treated as a compliance determination; public-system compliance is determined using the applicable regulatory monitoring framework.
Chlorine vs. Chloramine: What Is the Difference?
| Feature | Chlorine | Chloramine |
|---|---|---|
| Common use | Primary or residual disinfectant | Longer-lasting residual disinfectant |
| Stability in water | Less persistent | More persistent |
| Taste and odor | Can create a noticeable chlorine taste or smell | May create a treated-water or chemical taste |
| Filtration | Often easier to reduce with activated carbon | Usually needs more contact time or chloramine-specific media/performance |
Are Chlorine and Chloramine Safe?
Chlorine and chloramine are intentionally used to help protect public drinking water during distribution. EPA states that water containing chloramines and meeting regulatory standards is suitable for normal household uses such as drinking, cooking, and bathing.
That does not mean every household will like the taste or odor. Many people choose point-of-use filtration for drinking and cooking water while leaving the utility's disinfection process intact.
Why Reduce Chlorine or Chloramine at the Tap?
- Taste: residual disinfectants can affect the flavor of drinking water.
- Odor: some households notice a distinct treated-water smell.
- Coffee and tea: water chemistry can influence beverage flavor.
- Water-quality preferences: households may also review TTHM and HAA5 results in their water report, but chlorine reduction should not automatically be treated as proof of an equivalent reduction in disinfection byproducts.
- Personal preference: some people simply prefer filtered drinking water.
Can Chlorine Evaporate from Water?
Free chlorine can dissipate from uncovered water over time. Chloramine is more stable and generally does not dissipate nearly as quickly.
For routine drinking-water use, waiting for water to sit is less predictable than using a filtration method with documented performance for the disinfectant your utility actually uses.
How to Know Whether Your Water Uses Chlorine or Chloramine
The easiest method is to check your utility's Consumer Confidence Report or contact the water provider directly. Many utilities identify their disinfectant or secondary disinfection practices.
Free-chlorine and total-chlorine tests can provide useful screening information, but the utility remains the best source for identifying which disinfectant is intentionally used.
How to Reduce Chlorine and Chloramine from Drinking Water
The right method depends on which disinfectant your water provider uses, how much water you want to treat, and whether your goal is drinking-water-only filtration or whole-house treatment.
Activated Carbon
Activated carbon is widely used for chlorine taste-and-odor reduction. Performance depends on the media, flow rate, contact time, source-water conditions, and the amount of water already processed.
Chloramine is more persistent than free chlorine, so a generic chlorine claim should not be assumed to cover chloramine. Look for chloramine-specific test data for the exact filter you are considering.
Catalytic Carbon
Catalytic carbon is commonly used when chloramine reduction is a specific design goal. System sizing, flow rate, contact time, and maintenance all influence performance.
Reverse Osmosis Systems
Many reverse-osmosis systems include carbon prefilters that address disinfectants before water reaches the membrane. The carbon stages matter because chlorine or chloramine management should not be attributed solely to the membrane.
Whole-House Carbon Systems
Whole-house systems may be appropriate when the concern extends beyond drinking water to odor throughout the home. Chloramine applications typically require careful sizing and sufficient contact time.
Why Chloramine Is Harder to Reduce
Chloramine's stability is useful to water utilities because it lasts longer in distribution systems, but it also makes chloramine more demanding for filtration.
- Enough appropriate carbon media
- Sufficient contact time
- Suitable flow rate
- Regular maintenance and replacement
- Chloramine-specific performance data for the exact filter
A pitcher, refrigerator filter, or other small carbon filter may improve taste, but chloramine reduction should not be assumed unless the manufacturer provides relevant documentation.
Can Berkey® Filters Reduce Chlorine and Chloramine?
Yes—when the installed filter element has documented performance for the disinfectant you are trying to reduce. The important step is to match the evidence to the exact element in the system.
Phoenix Gravity New Millennium Edition™ Filter Elements
Phoenix Gravity elements are the current primary replacement option for compatible Berkey® gravity-fed systems. In the April 2026 Atom Testing Laboratory report, the displayed concentrations were:
| Test | Influent | Effluent | Conservative reduction |
|---|---|---|---|
| Free chlorine | 2.0 mg/L | <0.1 mg/L | >95.00% |
| Chloramine | 3.02 mg/L | <0.1 mg/L | >96.69% |
These are independent laboratory results under the documented test conditions, not universal guarantees for every source-water condition or service volume. Review the Berkey® Filter Test Results for the complete context.
Current NSF/ANSI 42 Listings
The Phoenix Gravity New Millennium Edition Filter Element PGF9-2 itself is listed by NSF under NSF/ANSI 42 for chlorine reduction. NSF's component-listing footnote states that it was tested to a capacity of 4,000 liters for reduction of chlorine and taste & odor.
Separately, NSF lists Travel Berkey®, Big Berkey®, and Royal Berkey® configurations featuring Phoenix Gravity New Millennium Edition™ Filter Elements under NSF/ANSI 42 for chlorine reduction and taste-and-odor reduction, with a listed 1,050-gallon service cycle.
Verify the official Phoenix PGF9-2 NSF/ANSI 42 component listing and the separate Travel/Big/Royal Berkey® NSF/ANSI 42 system listings. The same three Phoenix-equipped Berkey® configurations are also listed under NSF/ANSI/CAN 372 for lead-content requirements; Standard 372 is not a lead-reduction claim.
What About Existing Black Berkey® Elements?
Black Berkey® Elements are the original primary elements used in many existing Berkey® systems and have their own independent laboratory evidence relevant to chlorine and other contaminants. If your system currently uses Black Berkey® Elements, evaluate its performance using Black Berkey®-specific test results rather than applying Phoenix certification or laboratory data to the Black elements.
Standalone Black Berkey® replacement elements remain unavailable through normal authorized U.S. distribution channels. When a compatible primary replacement is needed, review the current Phoenix Gravity option and its separate evidence.
Our Berkey® Filter Test Results page brings the available Black Berkey® and Phoenix evidence together in one place.
Compare Current Berkey® Options
Review the element-specific test data, then choose a compatible system or replacement filter based on your household's water use and the disinfectant your utility uses.
Chlorine, Chloramine, and Plumbing Concerns
Plumbing-related metal levels depend on several factors, including pipe and fixture materials, water chemistry, corrosion-control practices, and stagnation time. If your home has older plumbing or a known lead service line, tap-specific testing is more informative than inferring lead or copper exposure from disinfectant type alone.
For more information, see the Lead in Drinking Water Guide.
Special Situations: Aquariums, Dialysis, and Brewing
Aquariums
Water used for aquariums requires appropriate conditioning or treatment for chlorine and chloramine. Follow aquarium-specific guidance rather than relying on a general household drinking-water filter claim.
Dialysis
Dialysis water requires specialized treatment and monitoring. Patients should follow instructions from their dialysis provider; household drinking-water filters are not substitutes for dialysis water treatment.
Coffee, Tea, and Brewing
Residual disinfectants can affect flavor, which is one reason some households filter water used for beverages and cooking.
Frequently Asked Questions
What is the difference between chlorine and chloramine?
Chlorine is a common drinking-water disinfectant. Chloramine is most commonly formed by adding ammonia to chlorine and is more persistent in distribution systems.
Can I remove chlorine by letting water sit out?
Free chlorine can dissipate from uncovered water over time, but the rate varies. Chloramine is more persistent, so letting water sit is not a reliable chloramine-removal method.
Does boiling remove chloramine?
Boiling should not be treated as a practical household chloramine-removal strategy. If chloramine reduction is the goal, use a method with relevant documented performance.
Do refrigerator filters remove chloramine?
Performance varies by filter. Check the exact model's chloramine-specific testing rather than assuming a chlorine claim also covers chloramine.
What type of filter is commonly used for chloramine?
Catalytic-carbon systems are commonly used when chloramine reduction is a design goal, but media volume, contact time, flow rate, and maintenance all matter.
Can Berkey® filters reduce chlorine?
Yes. Phoenix PGF9-2 itself is listed under NSF/ANSI 42 for chlorine reduction, and current Travel Berkey®, Big Berkey®, and Royal Berkey® configurations featuring Phoenix elements are separately listed for chlorine reduction and taste-and-odor reduction. Existing Black Berkey® Elements have separate product-specific laboratory evidence.
Can Phoenix Gravity elements reduce chloramine?
Independent April 2026 testing reported chloramine at 3.02 mg/L before filtration and below 0.1 mg/L after filtration, supporting a conservative reduction greater than 96.69% under the documented test conditions.
Is Phoenix NSF certified for chloramine reduction?
No current Phoenix PGF9-2 or Travel/Big/Royal Berkey® NSF listing shown here identifies chloramine reduction as a certified claim. Phoenix chloramine performance is documented separately through independent testing.
Should I filter the whole house or only drinking water?
If the concern is mainly drinking-water taste or odor, point-of-use filtration may be sufficient. If the concern affects water throughout the home, a properly sized whole-house system may be worth evaluating.
The Bottom Line
Chlorine and chloramine play important roles in public drinking-water treatment. If your goal is better taste or odor at the tap, first identify which disinfectant your utility uses, then choose a filtration method with documented performance for that exact concern.
Free chlorine is generally easier to reduce with carbon filtration. Chloramine is more persistent, so contact time, media choice, flow rate, and chloramine-specific testing matter more.
For Berkey® owners, Phoenix Gravity New Millennium Edition™ Filter Elements provide the current compatible replacement path for many systems. PGF9-2 itself is NSF/ANSI 42 listed for chlorine reduction, while Phoenix-equipped Travel, Big, and Royal Berkey® configurations are separately listed for chlorine and taste-and-odor reduction. Independent testing documents Phoenix chloramine performance under the stated laboratory conditions.