Overview
Arsenic is a naturally occurring element in rocks and soil that can dissolve into groundwater. It can also come from industrial and agricultural activity. In Florida it is usually natural and typically found at low levels.
In Florida, Arsenic was found in 467 community water systems serving about 2,817,710 people. 4 of those readings were above the federal legal limit, together serving 726 people. It was measured by 1,559 systems in all, so it was detected in 30% of the systems that tested for it.
The highest reading relative to the limit was at Willow Oak Estates in Polk County, at 159% of it.
Where it comes from: Erosion of natural deposits; runoff from orchards; industrial waste.
The standards
Legal limit (MCL)
0.01 ppm
Enforceable. A utility must stay at or under this.
Federal health goal (MCLG)
0 ppm
Health-based, not enforceable. Often lower than the limit, sometimes zero.
California public health goal
0.004 ppb
California OEHHA PHG (2004). For comparison the legal limit is 10 ppb.
Health effects the EPA associates with it: Skin damage. Circulatory problems. May increase the risk of certain cancers.
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
Reverse osmosis is the reliable household method. Anion exchange and iron-oxide adsorption media also work, but only on arsenic in its As(V) form. As(III) has to be oxidised first, which is why a system that works on one well can fail on another. Carbon does not remove arsenic.
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
CountySystemsOver limit
Hillsborough County488,126 people served611Polk County31,904 people served531Pasco County16,114 people served251Highlands County2,578 people served71Pinellas County669,313 people served4NoneBrevard County415,474 people served3NoneBroward County361,002 people served5NoneLee County303,920 people served4NoneSeminole County80,905 people served3NoneSarasota County60,231 people served2NoneManatee County58,584 people served1NoneMarion County47,592 people served90NoneCharlotte County36,796 people served3NoneCollier County36,308 people served5NoneOkaloosa County35,279 people served7NoneLake County33,671 people served57NoneOkeechobee County20,000 people served1NoneGadsden County15,186 people served5NoneMiami-Dade County13,963 people served4NoneWakulla County13,882 people served3NoneSumter County8,905 people served12NoneAlachua County7,052 people served8NoneLeon County6,718 people served10NoneLevy County5,227 people served6NoneVolusia County4,497 people served7NoneDesoto County3,301 people served1NoneOrange County3,265 people served6NoneHardee County3,250 people served3NonePutnam County3,116 people served6NoneCitrus County3,068 people served11NoneUnion County3,000 people served1NoneHernando County2,391 people served7NoneColumbia County2,305 people served13NoneClay County2,130 people served5NoneGilchrist County1,999 people served1NoneDixie County1,900 people served1NoneSanta Rosa County1,834 people served1NoneHolmes County1,599 people served4NoneWashington County1,458 people served1NoneFranklin County1,400 people served1NoneBradford County1,156 people served3NoneMartin County1,145 people served1NoneHamilton County819 people served1NoneCalhoun County800 people served1NoneOsceola County700 people served3NonePalm Beach County647 people served2NoneSuwannee County600 people served2NoneLiberty County444 people served1NoneSt. Lucie County299 people served2NoneSt. Johns County96 people served1NoneKnow when your water changes
We will email you when new readings, violations or health goals land for your system.
Or schedule a water consultation.
Data Sources
EPA SDWISSystem identity, population, countyret. 2026
FDEPFlorida drinking-water chemical monitoringret. 2026
CCREach utility’s own annual reportret. 2026
CA OEHHACalifornia public health goals, the health-based benchmark where one is publishedret. 2026
FWROur own benchmarks, only where no government body has published one, each citing the official source it is built onret. 2026
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.
