Why did Columbus switch from chlorine to chloramines?

The EPA tightened limits on trihalomethanes (THMs) — disinfection byproducts formed when free chlorine reacts with organic matter. Chloramines produce fewer THMs, making it easier for large utilities to comply. The tradeoff is that chloramines are harder to remove at home.

Can I use a regular Brita or carbon filter to remove chloramines?

Standard activated carbon (like in most pitcher filters) has limited effectiveness against chloramines. You need catalytic carbon, which has a different surface structure that catalyzes the breakdown of the chloramine bond. Most store-bought filters do not use catalytic carbon.

Is chloramine-treated water safe to drink?

At regulated levels, chloramine-treated water meets EPA safety standards. However, sensitive individuals — those with skin conditions, respiratory issues, or compromised immune systems — often benefit significantly from filtration.

My fish died after a water change. Could chloramines be the cause?

Yes. Chloramines are toxic to fish, reptiles, and amphibians. Standard dechlorination drops (sodium thiosulfate) do NOT neutralize chloramines. You need a product specifically labeled for chloramine removal, or use filtered water for aquariums.

Moderate Risk · City water

Chloramines

Columbus switched from chlorine to chloramines in 2004 — here's what that means for your home.

Free Water Test (614) 476-8711

EPA Limit

4 mg/L (MRDL)

Columbus Level

~2–3 mg/L typical in Columbus distribution system

Risk Level

Moderate Risk

Water Source

City water

Chloramines in Central Ohio

Columbus Division of Water switched to chloramines (monochloramine) as the primary disinfectant in 2004 to reduce trihalomethane (THM) byproducts. Chloramines are harder to remove than free chlorine and require catalytic carbon filtration.

What Is Chloramines?

Chloramines are formed when chlorine reacts with ammonia. Columbus and many other large utilities use monochloramine as a secondary disinfectant because it travels farther through the distribution system without forming as many trihalomethane (THM) byproducts as free chlorine. However, chloramines are more difficult to remove at home, can cause rubber seal degradation in plumbing, and are associated with skin and respiratory irritation in sensitive individuals.

Health Effects of Chloramines

Skin dryness, itching, and eczema flare-ups

Eye and nasal irritation during showering

Respiratory irritation (especially in hot showers)

Potential formation of iodoacids (emerging concern)

Harmful to fish and reptiles — cannot use chloramine-treated water in aquariums without treatment

Dialysis patients must use chloramine-free water

Home & Appliance Damage

Degrades rubber O-rings, gaskets, and seals in plumbing fixtures

Can cause pinhole leaks in copper pipes over time

Damages rubber components in water heaters and appliances

Signs You May Have Chloramines in Your Water

Chemical taste/smell

Chloramines produce a distinct "pool water" or medicinal taste and smell that many Columbus residents notice.

Dry, itchy skin after showering

Chloramines strip natural skin oils more aggressively than free chlorine, worsening eczema and dry skin.

Respiratory irritation

Hot showers volatilize chloramines into the air. People with asthma or allergies often notice worsening symptoms.

How to Remove Chloramines from Your Water

Not all filtration systems remove Chloramines. Here's what actually works.

Catalytic Carbon Whole-Home Filter

Recommended

Standard activated carbon does NOT effectively remove chloramines. You need catalytic carbon (like Centaur or Jacobi) which breaks the chloramine bond. Our whole-home systems use high-grade catalytic carbon media.

95–99% removal

Learn More

Reverse Osmosis for Drinking Water

An RO system at the kitchen sink removes chloramines from your drinking and cooking water with a multi-stage process including carbon pre-filtration.

95%+ removal

Learn More

Chloramines Questions & Answers

Related Contaminants

PFAS

Synthetic chemicals that never break down — and accumulate in your body over time.

Learn more

Hard Water

Columbus water averages 9–13 gpg — hard enough to cost the average family $800+ per year.