Chlorine Dioxide
Overview
Chlorine dioxide is a disinfectant used by some utilities. A limit is set on how much can remain in the water.
In Florida, Chlorine Dioxide was found in 1 community water system serving about 58,584 people.
The highest reading relative to the limit was at City of Bradenton in Manatee County, at 85% of it.
Where it comes from: Added for disinfection.
The standards
Enforceable. A utility must stay at or under this.
Health-based, not enforceable. Often lower than the limit, sometimes zero.
Federal MRDLG (40 CFR 141.54). For comparison the legal limit is 0.8 ppm.
Health effects the EPA associates with it: Anemia or nervous-system effects, especially in infants and young children.
The health goal is set on health alone. The legal limit is set as close to it as is technically and economically feasible, so treatment cost and available technology are written into the number a utility is measured against. A system at or under the limit is meeting the standard it is required to meet. Both numbers are shown so the distance between them is visible.
What removes it
Activated carbon reduces chlorine dioxide and the chlorite it leaves behind. Contact time matters, so size the filter rather than relying on a small in-line cartridge.
Treatment guidance describes the methods generally used for this contaminant. What your own tap actually carries depends on your plumbing and your service line as much as on the utility, which is what a test at the house tells you and an annual report cannot.
Where in Florida
Highest reported levels
Data Sources
These figures describe water as delivered by each utility, not what your home’s plumbing adds after it arrives. Informational; not a substitute for testing your own tap.