Chloramine in Columbus Water: What It Is, Why It's There, and How to Remove It
Columbus switched from chlorine to chloramines years ago. Most homeowners don't know the difference — but it matters for your filter choice, your fish tank, and your skin. Here's everything you need to know.
Jerry Pfeister
Founder & Owner
If you've noticed that your Columbus tap water has a faint chemical smell — not quite like a swimming pool, but something similar — you're detecting chloramines. Columbus, like most large Ohio cities, uses chloramines rather than free chlorine to disinfect its water supply.
Most homeowners don't know the difference. But it matters — especially if you're choosing a water filter, have sensitive skin, own fish or reptiles, or are concerned about disinfection byproducts.
What Are Chloramines?
Chloramines are compounds formed by combining chlorine with ammonia. The Columbus Division of Water adds both chemicals to the water supply, where they react to form monochloramine — the most common form used in water treatment.
The chemical reaction: Cl₂ + NH₃ → NH₂Cl (monochloramine) + HCl
Columbus switched to chloramines from free chlorine as part of compliance with EPA regulations on disinfection byproducts. Here's why:
The problem with free chlorine: When chlorine reacts with naturally occurring organic matter in water (leaves, algae, soil), it forms trihalomethanes (THMs) and haloacetic acids (HAAs) — compounds classified as possible human carcinogens at high long-term exposure. The EPA set strict limits on these byproducts in the 1990s.
Why chloramines help: Chloramines are more stable than free chlorine and produce significantly lower levels of THMs and HAAs. They also maintain disinfection residual throughout the distribution system better than free chlorine, which dissipates quickly.
The tradeoff: Chloramines create their own set of byproducts — including nitrosamines (some of which are classified as probable human carcinogens) and iodoacids — and they're significantly harder to remove from water than free chlorine.
Why Chloramines Are Harder to Remove Than Chlorine
This is the most important practical point for Columbus homeowners choosing a water filter.
Free chlorine is easy to remove. It evaporates if you let water sit for a few hours. A standard activated carbon filter removes it quickly and effectively.
Chloramines do not evaporate. Letting water sit overnight does nothing. A standard activated carbon filter removes chloramines very slowly and incompletely — you'd need a filter bed many times larger than typical residential filters to achieve meaningful removal.
What actually removes chloramines:
- Catalytic carbon (also called catalytic activated carbon or CAC) — specifically designed to break down chloramines. This is the media used in quality whole-house filters for chloramine removal.
- Reverse osmosis — removes chloramines effectively as part of comprehensive filtration
- Vitamin C (ascorbic acid) — neutralizes chloramines on contact; used in some shower filters and for dechlorinating water for fish tanks
If you have a standard pitcher filter or a basic under-sink carbon filter, it may not be removing chloramines effectively. Check whether it uses catalytic carbon or standard activated carbon.
Health Effects of Chloramines
The EPA considers chloraminated water safe to drink at the levels used in municipal treatment. However, there are specific concerns worth knowing:
Skin and respiratory irritation: Some people — particularly those with eczema, asthma, or chemical sensitivities — report increased skin irritation and respiratory symptoms from chloraminated water. Chloramines are less volatile than free chlorine, so they don't off-gas as readily in the shower, but they can still irritate sensitive skin.
Disinfection byproducts: Chloramines produce different byproducts than chlorine. Nitrosamines, formed when chloramines react with certain organic compounds, are classified as probable human carcinogens. The EPA regulates some nitrosamines but not all.
Aquarium and reptile owners: This is critical — chloramines are toxic to fish, amphibians, and reptiles. Unlike free chlorine, chloramines cannot be removed by letting water sit or by standard dechlorination drops. You must use a dechlorinator specifically labeled for chloramine removal (look for sodium thiosulfate + sodium ascorbate, or products containing "chloramine neutralizer").
Dialysis patients: Chloramines must be removed from water used in dialysis machines. Medical-grade water treatment systems handle this, but it's worth knowing if you or a family member is on home dialysis.
Brewing and winemaking: Chloramines inhibit yeast activity and can produce off-flavors in beer and wine. Home brewers in Columbus should use campden tablets (potassium metabisulfite) or a catalytic carbon filter to remove chloramines before brewing.
How to Remove Chloramines from Columbus Water
Whole-House Catalytic Carbon Filter
The most effective solution for whole-house chloramine removal. A catalytic carbon filter installed at the point of entry treats all water entering your home — showers, laundry, cooking, and drinking.
What to look for: Filters labeled with "catalytic carbon," "catalytic activated carbon," or "CAC" media. Standard activated carbon (GAC) is much less effective for chloramines.
Maintenance: Catalytic carbon media typically needs replacement every 3–5 years depending on water usage and chloramine levels.
Reverse Osmosis System (Drinking Water)
An under-sink RO system removes chloramines from your drinking and cooking water. It won't treat shower water or laundry, but it's the most comprehensive solution for the water you consume.
Shower Filter with Vitamin C
Vitamin C (ascorbic acid) neutralizes chloramines on contact. Some shower filters use vitamin C cartridges specifically for chloramine removal. These are less expensive than whole-house systems and effective for shower water specifically.
Limitation: Vitamin C cartridges need frequent replacement (every 1–3 months depending on usage) and don't treat the rest of the house.
What Doesn't Work for Chloramines
- Letting water sit or boiling (chloramines don't evaporate)
- Standard activated carbon pitcher filters (removes some, but slowly and incompletely)
- Standard chlorine dechlorination drops for aquariums (must use chloramine-specific products)
Frequently Asked Questions
Does Columbus water have chlorine or chloramines? Columbus uses chloramines — a combination of chlorine and ammonia — as its primary disinfectant. The switch from free chlorine happened to reduce trihalomethane (THM) byproducts.
Is chloramine in drinking water safe? The EPA considers chloraminated water safe at the levels used in municipal treatment. However, some people are sensitive to chloramines, and the disinfection byproducts they produce (including some nitrosamines) are a concern at high long-term exposure.
Will a Brita filter remove chloramines from Columbus water? Standard Brita filters use activated carbon, which removes some chloramines but not effectively. For meaningful chloramine removal, you need a filter with catalytic carbon media or a reverse osmosis system.
Why does my Columbus water smell like chemicals even after filtering? If you're using a standard carbon filter, it may not be removing chloramines effectively. Upgrade to a catalytic carbon filter or an RO system.
How do I know if my water filter removes chloramines? Check the product specifications for "catalytic carbon" or "CAC" media, or look for NSF/ANSI Standard 42 certification specifically for chloramine reduction. Standard activated carbon filters are not certified for chloramine removal.
Is chloramine dangerous for my fish tank? Yes. Chloramines are toxic to fish and must be removed before adding tap water to an aquarium. Use a dechlorinator specifically labeled for chloramine removal — standard dechlorination products may not work.
Pure Aqua Columbus installs whole-house catalytic carbon filters throughout Central Ohio. If you're concerned about chloramines in your Columbus water, we'll test your water and recommend the right solution.
