Water Filter for Chloramine: Removal Guide (2026)

📅 Last Updated: July 16, 2026

Published January 2026 | Written by Filter Tested Editorial Team | Last updated: July 11, 2026 | Read our methodology

Chloramine is not chlorine. While the two disinfectants are related, chloramine is significantly harder to remove from drinking water and requires different filtration technology. Standard activated carbon, the workhorse of residential water filtration, reduces only 30-50% of chloramine on a single pass. If your water utility uses chloramine and you want it gone, you need to understand what works, what does not, and why the distinction matters for your health and your home.

Quick Summary

What Is Chloramine?

Chloramine is a chemical compound formed when free chlorine reacts with ammonia. The most common form in drinking water is monochloramine (NH2Cl), where one chlorine atom bonds with two hydrogen atoms and one nitrogen atom from ammonia. Water utilities add ammonia to chlorinated water in a controlled reaction that converts free chlorine to monochloramine. The process has been used in US water treatment since the 1930s, with adoption accelerating in the 1970s as the EPA tightened regulations on disinfection byproducts.

Monochloramine is a weaker disinfectant than free chlorine. It kills bacteria and viruses more slowly and is less effective against protozoan cysts like Giardia and Cryptosporidium. To compensate, utilities that use chloramine typically maintain higher total disinfectant levels or combine chloramine with other treatment steps. Despite its weaker disinfecting power, chloramine offers advantages in distribution that have driven its widespread adoption.

The EPA maximum residual disinfectant level (MRDL) for chloramine is 4.0 mg/L, measured as chlorine equivalent. Most utilities target 2.0-3.0 mg/L to maintain adequate residual throughout the distribution system while staying well below the regulatory limit.

Chloramine vs. Chlorine: Key Differences

Understanding why chloramine behaves differently from chlorine explains why it requires different filtration approaches.

Stability: Free chlorine degrades relatively quickly in water, losing approximately half its concentration every 4-6 hours depending on temperature and organic content. This means chlorine residuals can drop to ineffective levels in the far reaches of a distribution system. Chloramine is far more stable, persisting for days with minimal degradation. This stability allows utilities to maintain disinfectant residuals throughout large distribution networks, reducing the risk of bacterial regrowth in water mains.

Disinfection byproducts: When chlorine reacts with natural organic matter in water, it forms trihalomethanes (THMs) and haloacetic acids (HAAs), both linked to increased cancer risk at chronic exposure levels. The EPA regulates total THMs at 80 -g/L and HAAs at 60 -g/L. Chloramine produces THMs and HAAs at roughly one-third to one-half the rate of free chlorine, making it an attractive option for utilities struggling to meet EPA byproduct regulations.

Removal difficulty: Free chlorine is readily adsorbed by activated carbon through a chemical reaction that converts chlorine to chloride. This reaction is fast and efficient, which is why standard carbon filters work well for chlorine. Chloramine's chemical structure makes it resistant to this adsorption. Carbon can still remove chloramine, but the reaction is slower and requires more contact time. Standard carbon filters running at typical residential flow rates achieve only 30-50% chloramine reduction. Effective removal requires either upgraded carbon (catalytic carbon), longer contact times (larger filter beds), or additional technologies like KDF-85.

Lead leaching: This is one of the most significant and underappreciated differences. Chloramine can increase lead leaching from older plumbing systems, particularly those with lead service lines or lead solder. The mechanism involves chloramine breaking down into ammonia, which can complex with lead and increase its solubility in water. This effect was implicated in the Flint, Michigan water crisis, where a switch to chloramine-treated water contributed to elevated lead levels in homes with lead plumbing. If you live in an older home with potential lead plumbing and your utility uses chloramine, lead filtration becomes especially important.

Which Cities Use Chloramine?

Over 30% of US water utilities serving large populations use chloramine as either their primary or secondary disinfectant. Major metropolitan systems using chloramine include:

This list is not exhaustive. Water treatment practices change, and some utilities use chlorine in certain seasons and chloramine in others. The only reliable way to know what disinfectant your utility uses is to check your annual Consumer Confidence Report (CCR), which lists disinfectant type and average levels. If you cannot find your CCR, call your water utility directly and ask whether they use free chlorine or chloramine.

Health and Household Effects

Drinking Water Effects

At concentrations of 2-4 mg/L, chloramine produces a distinct medicinal or swimming-pool-like taste and odor that many people find unpleasant. The taste threshold varies by individual, with some people detecting chloramine at less than 0.5 mg/L. While EPA considers chloramine safe at regulated levels, some sensitive individuals report skin irritation, respiratory symptoms, or digestive discomfort that they attribute to chloramine exposure. The scientific evidence for these effects in the general population at typical water concentrations is limited, but individual sensitivity varies.

Shower and Bath Effects

Chloramine volatilizes less readily than free chlorine, meaning less is released as vapor during hot showers. However, some chloramine does aerosolize, and sensitive individuals may experience respiratory irritation, dry skin, or eye irritation. Because chloramine is more stable than chlorine, it persists longer in heated water. Whole-house filtration is therefore more important for chloramine than for chlorine if you are concerned about shower exposure.

Aquarium and Medical Concerns

Chloramine is toxic to fish and amphibians at standard water treatment levels. Unlike chlorine, which can be removed with simple dechlorinators, chloramine requires products that specifically break the chlorine-ammonia bond. Fish keepers in chloraminated water areas must use water conditioners labeled for chloramine removal.

For kidney dialysis patients, chloramine must be removed from water used for dialysis because it crosses dialysis membranes and causes hemolysis (destruction of red blood cells). Dialysis centers use specialized dechloramination systems and test water rigorously.

Filtration Technologies for Chloramine Removal

Standard Activated Carbon (30-50% Removal)

Standard activated carbon, including the granular activated carbon (GAC) and carbon block filters found in most pitcher, faucet, and under-sink systems, reduces chloramine by 30-50% on a single pass at typical flow rates. The removal mechanism is catalytic breakdown of the chloramine molecule on the carbon surface, releasing nitrogen gas and chloride. This reaction is slow; for high removal rates, water must have extended contact time with the carbon surface, which is not achievable in small residential filters at normal flow rates.

For a household with 2-3 mg/L chloramine, a standard carbon filter might reduce this to 1-1.5 mg/L. Whether this is adequate depends on your sensitivity and goals. For most people seeking meaningful chloramine reduction, standard carbon alone is insufficient.

Catalytic Carbon (90-99% Removal)

Catalytic carbon is activated carbon that has undergone additional high-temperature processing to alter its surface chemistry. This processing creates catalytic sites on the carbon surface that accelerate the breakdown of chloramine molecules. Catalytic carbon removes 90-99% of chloramine at standard residential flow rates, making it the preferred media for whole-house chloramine filtration.

The enhanced reactivity of catalytic carbon comes from increased electron transfer capability at the carbon surface. Chloramine molecules adsorb to these catalytic sites and decompose much faster than on standard carbon. Contact time requirements are roughly 50-75% lower than standard carbon for equivalent removal, meaning catalytic carbon beds can be smaller or flow rates can be higher while maintaining performance.

Catalytic carbon costs 30-50% more than standard activated carbon but is the only practical option for whole-house chloramine removal. All major whole-house systems marketed for chloramine removal use catalytic carbon as the primary or exclusive media.

KDF-85 (80-90% Removal)

Reverse Osmosis (95-99% Removal)

Reverse osmosis systems remove chloramine through their carbon pre-filters (which adsorb a portion) and the RO membrane (which rejects the remainder along with dissolved contaminants). A properly configured RO system with quality carbon pre-filtration achieves 95-99% chloramine removal. RO is the most effective point-of-use option for drinking water but does not address shower, bath, or appliance water.

The carbon pre-filters in an RO system serve dual purposes: they protect the membrane from chlorine and chloramine damage (membranes are sensitive to oxidants) and they remove a portion of the chloramine before it reaches the membrane. Catalytic carbon pre-filters in RO systems extend membrane life and improve chloramine removal compared to standard carbon pre-filters.

Best Whole-House and Point-of-Use Systems

How to Test for Chloramine

There are three practical ways to determine whether your water contains chloramine:

Consumer Confidence Report (CCR): Your water utility's annual CCR explicitly states the disinfectant used. Look for the section labeled "Disinfectant" or "Disinfection Method." If the report lists "chloramine," "monochloramine," or "combined chlorine," your water is chloraminated.

Chloramine Test Kit ($20-30): Home test kits measure total chlorine, free chlorine, and combined chlorine (chloramine). The difference between total chlorine and free chlorine equals combined chlorine, which is primarily monochloramine. Kits from Hach, LaMotte, and API provide accurate results for residential testing. Follow the instructions carefully; chloramine testing requires a two-step reagent process that differs from simple chlorine testing.

Observation Method: Fill a clean glass with tap water and let it sit uncovered for 24 hours. If the chlorine smell dissipates significantly, your water likely uses free chlorine. If the medicinal smell persists, chloramine is probably present. This method is imprecise but can indicate which disinfectant type to suspect.

Why Shower Filtration Matters for Chloramine

Most discussions about water filtration focus on drinking water. But chloramine affects shower water too, and for some individuals, shower exposure is the dominant route of contact.

Hot shower water aerosolizes a portion of the chloramine, creating inhalable particles. While chloramine volatilizes less than free chlorine, it is not non-volatile. A 10-minute shower in chloraminated water can result in respiratory exposure comparable to drinking 1-2 liters of the same water. Individuals with asthma, allergies, or chemical sensitivities may notice respiratory symptoms in chloraminated water areas that improve with shower filtration.

Skin exposure is another consideration. Chloramine strips natural oils from skin and hair more slowly than chlorine but can contribute to dryness and irritation over time. Whole-house catalytic carbon filtration addresses shower water, bath water, and appliance water simultaneously, making it the comprehensive solution for chloramine-conscious households.

If whole-house filtration is not feasible, consider a catalytic carbon shower filter. Standard KDF/carbon shower filters achieve only 30-50% chloramine reduction because the contact time is too short. A few specialized shower filters now use catalytic carbon, though options remain limited compared to the broader shower filter market.

Why Pitcher and Faucet Filters Fall Short

The structural limitation is contact time. A pitcher filter processes water in seconds as gravity pulls it through a thin carbon bed. Chloramine requires more contact time than chlorine for equivalent removal because the catalytic breakdown reaction is slower. Even well-designed pitcher filters with catalytic carbon cannot provide enough contact time for 90%+ removal. Under-sink and whole-house systems succeed where pitchers fail because they use larger carbon beds and force water through at controlled flow rates that optimize contact time.

Our Methodology

Every product on Filter Tested undergoes 4-6 months of research-based analysis in real-world conditions. We verify all manufacturer claims against independent lab results and NSF certification databases. Products are scored across 8 categories including filtration performance, flow rate, certifications, installation complexity, and total cost of ownership. Learn more about how we test.

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