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Filtering Chloramine: Notes for Oviedo and Black Hammock
A whole house water filter for chloramine has to be certified for chloramine, not just chlorine. That matters mostly in Oviedo and the county's Black Hammock area, the only local water treated with chloramine.
Most taps north of Orlando are disinfected with plain chlorine. Oviedo is the exception: its report describes forced-draft aeration followed by chloramine disinfection, and that changes what a whole-house filter has to do if you want the taste or smell gone.
Who in our area gets chloramine?
Oviedo customers, and Seminole County Utilities' Black Hammock service area, which buys its water from Oviedo. The county's 2024 water quality report says Black Hammock water is run through aeration towers and then chloraminated, and it is the only county area that receives chloramine. Chlorine is the disinfectant everywhere else, from Winter Springs and Altamonte Springs to Longwood, Sanford, Lake Mary, Orange County Utilities and the other county areas. OUC says outright that it does not use chloramines.
How much disinfectant is in the water?
Each yearly report lists an average and a range. Oviedo's chloramine averaged 2.30 ppm in 2024. On the chlorine side in 2025, Longwood averaged 1.68 ppm, Sanford 1.4 ppm, Altamonte Springs 1.1 ppm and Lake Mary 0.58 ppm. Sanford's report lists the maximum residual disinfectant level as 4 ppm for comparison.
Yearly averages in ppm from each utility's report (Oviedo 2024, others 2025)
Source: City of Oviedo 2024 report; City of Longwood 2025 CCR; City of Sanford 2026 report; City of Altamonte Springs 2025 report; City of Lake Mary 2025 report
Why isn't a chlorine filter enough for chloramine?
Because the certifications are separate. Chlorine reduction and chloramine reduction are both claims made under NSF/ANSI 42, but NSF's own certified-product listing keeps "Chloramine Reduction" as its own category, and listed products show the two as different claims. A filter certified only for chlorine has not been shown to handle chloramine. If you live in Oviedo or Black Hammock, look for the chloramine claim by name on the certification.
What do the NSF numbers on the box mean?
They tell you what a filter was tested to do. EPA WaterSense and CDC describe them this way:
NSF/ANSI standards you'll see on home water equipment
| Standard | What it covers |
|---|---|
| NSF/ANSI 42 | Aesthetic effects such as taste and odor, including chlorine and chloramine claims |
| NSF/ANSI 53 | Health effects |
| NSF/ANSI 58 | Reverse osmosis systems |
| NSF/ANSI 401 | Emerging compounds and incidental contaminants |
| NSF/ANSI 44 | Water softeners |
CDC's page on choosing home water filters notes that Standard 42 filters and activated carbon improve taste and smell, while health claims sit under other standards. EPA's WaterSense selection booklet lists the same family of standards. Match the claim to the problem you actually have.
What should you know before buying one?
Know what you're trying to remove and confirm it with a number. On city water, your utility's report already gives the disinfectant type and level, so the question is whether you want it out of the whole house or only at the kitchen tap. On a well there is no disinfectant to remove; the test that matters covers bacteria, nitrate, hydrogen sulfide, iron and hardness, as our private wells story explains. If hardness is the real complaint, a carbon filter won't touch it; see water softeners.
Does a whole-house filter need upkeep?
Yes, and skipping it can make the water worse. Sanford's FAQ warns that home filters need strict, regular maintenance and can turn into sources of bacteria and slime without it. Follow the maker's schedule for media changes and backwashing, and keep a dated note of each one.
Can carbon handle sulfur smell too?
Only in small amounts, and catalytic carbon has a condition. Penn State Extension says ordinary activated carbon may work when hydrogen sulfide is below about 1.0 mg/L, and that catalytic carbon needs at least 4.0 mg/L of dissolved oxygen in the water. Stronger sulfide calls for other methods, laid out in the rotten-egg smell story. Well owners should also note that Florida DOH lists installing or repairing a filter among the times to disinfect the well.
Readers often ask
Does Winter Springs use chloramine?
No. The 2025 Winter Springs report describes cascade aeration and chlorine at all three plants. Oviedo and Black Hammock are the local chloramine areas.
Can I tell chloramine from chlorine by smell?
Don't rely on your nose. Your utility's yearly report names the disinfectant, and the utility can confirm it by phone.
Will a pitcher filter remove chloramine?
Only if it carries a chloramine reduction claim under NSF/ANSI 42. Check the certification listing for that exact claim.
Do I need a whole-house filter on a private well?
Well water has no utility disinfectant to remove. Test first for bacteria, nitrate, sulfide, iron and hardness, then choose equipment from the results.
Why did my water taste different after a filter change?
Follow the maker's start-up and flushing steps for new media. If an odor or musty taste shows up on a well, DOH lists that among the signs to disinfect and retest.
Where this came from
- City of Oviedo — 2024 Annual Drinking Water Quality Report — chloramine and treatment
- Seminole County Utilities — 2024 Water Quality Report — Black Hammock buys Oviedo water
- NSF — Listing: NSF/ANSI 42 Chloramine Reduction — chloramine as a separate claim
- CDC — About Choosing Home Water Filters — what standards cover
- EPA WaterSense — Selecting Water Treatment Systems — NSF/ANSI standard names
- City of Sanford — 2026 Annual Water Quality Report — chlorine level and MRDL
- City of Longwood — 2025 CCR — chlorine level
- City of Altamonte Springs — 2025 Drinking Water Quality Report — chlorine level
- City of Lake Mary — 2025 Water Quality Report — chlorine level
- Penn State Extension — Hydrogen Sulfide in Water Wells — carbon limits for sulfide