Haloacetic acids (HAA5) in Tap Water
HAA5 is a group of five haloacetic acids: disinfection by-products that, like TTHMs, form when chlorine reacts with organic matter.
Formed in-system during chlorination of water containing organic material.
- 1Chlorination of water with organic matter
A result is read with its context
Reported from utility and state compliance monitoring, typically as a running annual average. PurityMap publishes this substance per water system on individual system and city-report pages, where the source dataset provides a value.
- Above reference
- Evidence exceeds a reference level.
- Detected
- This substance was found in the monitoring record. Being present is not the same as being above a reference level, and this signal does not say which.
- Not detected
- Somebody looked and the laboratory reported nothing above its reporting limit. This is a result, and it is not the same as nobody looking.
- Not monitored
- No sampling for this substance has been reported for this system. Nothing is known either way, and an empty row is not a clean one.
58 cities where haloacetic acids (HAA5) was detected
- AllentownPA→
- AmarilloTX→
- AshevilleNC→
- AtlantaGA→
- AustinTX→
- BethlehemPA→
- BiloxiMS→
- BoiseID→
- BostonMA→
- BuffaloNY→
- CaryNC→
- CharlotteNC→
- ChattanoogaTN→
- ChicagoIL→
- ClevelandOH→
- DallasTX→
- DenverCO→
- DurhamNC→
Showing 18 of 58. Open a state for its full list. The scope of PurityMap’s record, not a national prevalence estimate.
What can carry a haloacetic acids (HAA5) reduction claim
- Activated carbon
Highly porous adsorption media targeting chlorine, disinfection byproducts, volatile organic compounds, and organic chemicals.
- Reverse osmosis
Semi-permeable membrane separation removing dissolved minerals, heavy metals, and persistent fluorinated chemicals down to 0.0001 microns.
Boiling does not remove a dissolved chemical compound and can concentrate it. Many pitcher and refrigerator filters carry no verified claim for a compound like this at all.
A finding establishes the need, the need names the capability, the capability requires a verified certification. No product appears before that sequence completes. Filter Finder →
Frequently asked
Answers cite the same records as the page. How PurityMap analyzes water data
HAA5 is a group of five haloacetic acids: disinfection by-products that, like TTHMs, form when chlorine reacts with organic matter.
The enforceable federal limit is 60 µg/L (MCL). The published health benchmark reads: 60 µg/L federal limit (MCL). PurityMap reads every measurement against its stated benchmark and never sets its own.
Chlorination of water with organic matter.
Sustained exposure above the limit is associated with possible cancer and developmental risks in studies. Managed by controlling organic precursors and disinfection practice.
Treatment technologies commonly certified to reduce Haloacetic acids (HAA5) include Activated carbon, Reverse osmosis. Match the exact certified claim to your water before buying. Holding a format is not the same as holding the claim.
In PurityMap's published record, Haloacetic acids (HAA5) was detected in 58 cities (of 58 with a result) across 26 states. This is the scope of our record, not a national prevalence estimate.