Chlorine or chloramine: which does your town use?
Updated July 2026
Short answer: Covington, Mandeville, Slidell, Hammond, and the Lacombe and Cross Gates area use chloramine. Most other Northshore towns use plain chlorine. The difference decides which carbon filter actually works in your house.
The town-by-town split
Every public water system publishes its disinfectant in its annual report. Here is the current picture, from the 2024 and 2025 reports:
| Chloramine towns | Covington (0.9 ppm average), Mandeville (1.8 ppm), Slidell, Hammond, Lacombe and Cross Gates |
|---|---|
| Chlorine towns | Madisonville, Abita Springs, Pearl River (1.5 ppm), Ponchatoula, Amite, Folsom, Bayou Liberty, and most parish systems including River Oaks (1.7 ppm) |
Subdivision systems vary, which is one more reason your neighborhood matters more than your city. Look yours up on our reports page and the answer is right there.
Why it changes your filter
Plain chlorine comes out with ordinary activated carbon. Chloramine is chlorine bonded with ammonia, and it grips on. Standard carbon barely touches it, which is why some homes install a filter and still taste the pool. Chloramine towns need catalytic carbon, a media processed specifically to break it down.
This is the single most common spec mistake in our area. If you are getting quotes, ask each company one question: which carbon are you putting in the tank, and why? The answer tells you whether they looked at your town's report.