Chloramine filters: what to look for, and which cities use chloramine
If your utility uses chloramine instead of chlorine, a filter that says “reduces chlorine” isn’t enough. Look for a separate chloramine reduction claim under NSF/ANSI 42. Here’s how to check, plus which of the 25 largest US cities use chloramine.
What chloramine is
Chloramines are disinfectants most often made by adding ammonia to chlorine. Utilities use them to keep water disinfected as it travels through the pipes to your home, because they last longer than chlorine. Water systems have used chloramines since the 1930s, and EPA says more than one in five Americans drink water treated with them. Source: EPA: Chloramines in drinking water.
Some utilities switched from chlorine to chloramine to meet federal limits on disinfection byproducts, which form when disinfectants react with natural material in the water. Chloramine forms fewer of them. Sources: EPA: Chloramines in drinking water; Denver Water: Disinfection byproducts.
EPA caps chloramine in tap water at 4.0 mg/L (measured as chlorine), the same cap as for chlorine. Source: EPA: National Primary Drinking Water Regulations.
Do you need to remove it?
For drinking, cooking and bathing, EPA says no: water with chloramine that meets federal standards is safe to use, and EPA says it doesn’t need to be removed. Sources: EPA: Chloramines in drinking water; EPA Q&A: How can I remove monochloramine from my drinking water? (PDF, 2009).
Most people who filter it do so for taste or smell. The two real exceptions are fish tanks and kidney dialysis machines, covered below. If you have a health question about your water, ask your doctor and your utility.
The certification to look for
NSF/ANSI 42 is the standard for “aesthetic” effects such as taste and odor. It covers both point-of-use filters (pitcher, faucet, under-sink) and whole-house systems. Chlorine and chloramine are separate claims under it, and the claims vary by product. Source: NSF: NSF/ANSI 42, 53 and 401 filtration standards.
EPA also says chloramine can be harder to remove than chlorine. That’s why a chlorine claim doesn’t tell you anything about chloramine. Source: EPA Q&A: How can I remove monochloramine from my drinking water? (PDF, 2009).
| The label or listing says | What it means for chloramine |
|---|---|
| NSF/ANSI 42: chloramine reduction | Certified for chloramine. This is the claim you want. |
| NSF/ANSI 42: chlorine reduction (or “chlorine, taste and odor”) | Not a chloramine claim. It doesn’t show the product was tested on chloramine. |
| NSF/ANSI 53 or 58 only | These cover health-related contaminants such as lead or PFAS (53) and reverse osmosis systems (58). Check the product’s NSF/ANSI 42 claims separately for chloramine. |
| “Tested to NSF standards” or “removes chloramine” with no certifier named | A marketing claim. Look the product up in a certifier’s listing before relying on it. |
You don’t need every certification. If you only care about chloramine taste, the NSF/ANSI 42 chloramine claim is the one to match. If you also want lead or PFAS reduction, see the certification table in our city guide.
How to check a filter in two minutes
- Find the exact model number of the filter or replacement cartridge (not just the brand).
- Search for it in a certifier’s listing: NSF certified drinking water treatment units listings or WQA certified products. EPA’s own guidance points to these listings and says to search NSF/ANSI 42 for chloramine reduction. Source: EPA Q&A: How can I remove monochloramine from my drinking water? (PDF, 2009).
- Open the listing and confirm chloramine reduction appears among its claims. If only chlorine appears, it isn’t certified for chloramine.
- Note the rated capacity (gallons) in the listing or manual and replace the cartridge on schedule. EPA stresses on-schedule replacement for home filters. Source: EPA: Reducing PFAS in your drinking water with a home filter.
EPA doesn’t test or certify home filters itself; it relies on third-party certifiers. Source: EPA Q&A: How can I remove monochloramine from my drinking water? (PDF, 2009). Other accredited certifiers include IAPMO, CSA, and UL: IAPMO R&T product listing directory, CSA Group product listing, UL Product iQ.
What doesn’t remove chloramine
EPA lists three common methods that don’t work on chloramine: Source: EPA Q&A: How can I remove monochloramine from my drinking water? (PDF, 2009).
- Boiling doesn’t remove it.
- Letting water sit out at room temperature doesn’t remove it. This is the big difference from chlorine, which does fade from standing water. Denver Water makes the same point for aquarium owners. Source: Denver Water: Disinfection byproducts.
- A reverse osmosis membrane doesn’t remove it. Many RO systems include other filter stages, so check whether the whole system lists an NSF/ANSI 42 chloramine claim.
Which big cities use chloramine
Of the 25 largest US cities we cover, 12 have a main utility that uses chloramine. San Jose has a mix depending on the source serving your area, and we haven’t yet confirmed which one Oklahoma City uses. Water varies by neighborhood and provider, so check your own utility’s annual report.
| City | Main utility | Disinfectant | What the utility reports | Source |
|---|---|---|---|---|
| Los Angeles, CA | Los Angeles Department of Water and Power | Chloramine | Chloramines. | 2026 Drinking Water Quality Report (2025 data) |
| Houston, TX | Houston Public Works | Chloramine | Chloramines in the main system (average 2.8 mg/L). | 2025 Water Quality Report |
| Philadelphia, PA | Philadelphia Water Department | Chloramine | Chloramine. | 2025 Drinking Water Quality Report |
| San Diego, CA | City of San Diego Public Utilities Department | Chloramine | Chloramines (average 1.75 mg/L). | 2025 Annual Drinking Water Quality Report |
| Dallas, TX | Dallas Water Utilities | Chloramine | Chloramine. DWU's water quality page says "We use chloramine instead of chlorine" (2025 total chlorine residual averaged 2.97 mg/L). | Dallas Water Utilities: water quality information |
| Fort Worth, TX | Fort Worth Water | Chloramine | Chloramines (2022 average 3.4 mg/L). | 2022 Water Quality Report (older: the latest report wasn't reachable) |
| Austin, TX | Austin Water | Chloramine | Chloramine (average 2.3 mg/L). | 2025 Water Quality Report |
| San Jose, CA | San Jose Water | Chlorine or chloramine | The report says chloramine and chlorine may be present, depending on the water source serving your area. | 2025 Consumer Confidence Report |
| Indianapolis, IN | Citizens Energy Group | Chloramine | Chloramines. | 2025 Water Quality Report |
| San Francisco, CA | San Francisco Public Utilities Commission | Chloramine | Chloramine (average 2.6 mg/L). | 2025 Water Quality Report |
| Denver, CO | Denver Water | Chloramine | Chloramines are added after filtration. | Denver Water: treated water quality summary |
| Oklahoma City, OK | Oklahoma City Utilities | Not confirmed Unverified | The report lists the disinfectant only as "Chlorine/Chloramines" (running annual average 3.0 mg/L). We haven't confirmed which one on an official page. | Consumer Confidence Report, calendar year 2025 (state-hosted, http only) |
| Washington, DC | DC Water | Chloramine | Chloramine for most of the year, with a temporary switch to free chlorine each year for system maintenance. | 2026 Water Quality Report (2025 data) |
| Boston, MA | Boston Water and Sewer Commission | Chloramine | Monochloramine (average 1.99 mg/L). | 2026 Water Quality Report (2025 data) |
mg/L values are the utility’s reported disinfectant level, under EPA’s 4.0 mg/L cap. Washington, DC switches temporarily to free chlorine each year for system maintenance, so the taste can change during that time. The other 11 cities use chlorine; see the full city list.
Fish tanks and home dialysis
- Fish and aquariums. Chlorine and chloramine harm fish because they enter the bloodstream through the gills. Water can be used safely in aquariums with products sold at aquarium supply stores. Look for one that says it treats chloramine, since letting water stand won’t clear it. Sources: EPA Q&A: Can chloraminated or chlorinated water be used for dialysis or in an aquarium? (PDF, 2009); Denver Water: Disinfection byproducts.
- Kidney dialysis. Chloramine must be removed from water used in dialysis machines because that water contacts blood. People on dialysis can still drink chloraminated water. If you do dialysis at home, ask your doctor and your dialysis provider about water treatment rather than relying on a kitchen filter. Source: EPA Q&A: Can chloraminated or chlorinated water be used for dialysis or in an aquarium? (PDF, 2009).
More answers from EPA: EPA: Common health questions related to monochloramine.
We don’t recommend specific chloramine filters yet. When we do, every pick will link to its certification listing, and any affiliate link will be disclosed. See our affiliate disclosure and sources and methodology.