Local Water Quality
Chloramines in Largo Water: What They Are and How to Remove Them
If you've noticed a persistent chemical taste or smell from your Largo tap water — something that doesn't quite smell like a swimming pool but isn't clean either — chloramines are almost certainly the cause. Pinellas County Utilities, like most large Florida water systems, uses chloramines as the primary residual disinfectant. Understanding what chloramines are and how to remove them is essential for Largo homeowners who want genuinely clean drinking water.
What Are Chloramines?
Chloramines are chemical compounds formed when chlorine is combined with ammonia during water treatment. They're not accidental — utilities add them intentionally as a disinfectant that persists through miles of distribution pipes without breaking down as quickly as free chlorine.
The switch from chlorine to chloramines became widespread after EPA regulations in the 1990s tightened limits on trihalomethanes (THMs) — cancer-associated compounds that form when free chlorine reacts with natural organic matter in source water. Chloramines produce fewer regulated THMs, making them attractive to utilities under regulatory pressure.
There are three types: monochloramine, dichloramine, and nitrogen trichloride. Monochloramine is the intended form; the other two form under certain pH and temperature conditions and are associated with stronger odors. In Florida's summer heat, water sitting in distribution pipes can shift toward the more pungent forms — which is why tap water can smell worse during hot weather.
Why Chloramines Are More Problematic Than Chlorine
They're harder to remove at home. Free chlorine dissipates rapidly — a standard carbon filter removes it within seconds. Chloramines are far more stable and require catalytic activated carbon, longer contact time, or both. Standard pitcher filters and basic under-sink carbon units often fail to adequately reduce chloramines.
They form different disinfection byproducts. While chloramines produce fewer THMs, they generate iodoacids and N-nitrosodimethylamine (NDMA) — identified as potential carcinogens. These compounds aren't consistently regulated, meaning they may be present without appearing in annual water quality reports.
They're corrosive to certain plumbing materials. Chloraminated water accelerates leaching of lead from lead-containing solder, brass fixtures, and older service lines. This is particularly relevant in Largo's older housing stock, where pre-1986 homes may have lead solder at pipe joints throughout the plumbing system.
They cannot be neutralized by standard methods. Sodium thiosulfate drops — the standard way to dechlorinate water for fish tanks — do not remove chloramines. This illustrates that chloramines behave differently in chemical processes and interact with home systems (humidifiers, CPAP machines, steam irons) in ways free chlorine does not.
Largo's Chloramine Profile
Pinellas County Utilities' annual Consumer Confidence Report documents chloramine levels in the distribution system. Total chlorine typically reads between 1.5 and 3.0 mg/L at various monitoring points throughout Largo and the county. Summer months tend to see higher residuals as the utility compensates for faster disinfectant decay in warmer water.
The surface water component of Largo's supply contains more natural organic matter than groundwater sources. When chloramines interact with this organic material in older distribution segments, they can generate higher levels of disinfection byproducts at specific taps — again, not reflected in distribution-wide averages.
How to Effectively Remove Chloramines
Catalytic activated carbon is the most practical whole-house and point-of-use solution. Unlike standard activated carbon, catalytic carbon has a modified surface that actively breaks down chloramine molecules. High-flow whole-house systems using catalytic carbon can remove chloramines at every tap, shower, and appliance in the home.
Reverse osmosis (RO) is the most thorough approach for drinking water. A properly configured RO system with activated carbon pre-filters removes chloramines, disinfection byproducts, lead, nitrates, and virtually everything else. For Largo homeowners in pre-1986 homes where lead is a concern, an under-sink RO system provides comprehensive protection at the drinking tap.
What doesn't work: Standard carbon block pitcher filters, simple inline filters on refrigerators, and basic aerators do not adequately remove chloramines. If you're relying on these and wondering why your water still tastes chemical, this is why.
Whole-House vs. Point-of-Use
A whole-house catalytic carbon filter treats water at the point of entry, removing chloramines before they reach your showers, laundry, and appliances. This is particularly valuable because chloramines in shower steam are inhaled — dermal absorption in the shower can be significant for households with asthma or chemical sensitivities.
For most Largo families, the combination of whole-house carbon filtration plus under-sink RO delivers the most comprehensive solution: clean water for bathing, clean water for drinking, and protection for plumbing and appliances throughout the home. The H2O Heroes serve Largo and all of Pinellas County with water testing and treatment solutions tailored to your home's specific needs.