Overview
1,4-Dioxane is an industrial solvent and a stabiliser once added to degreasers and consumer products. It moves through soil and groundwater almost as freely as water itself, which is why it travels far from where it was spilled. EPA monitored it nationwide in 2013 to 2015 and has set no limit for it.
In Florida, 1,4-Dioxane was found in 44 community water systems serving about 6,258,361 people. Nobody has set a legal limit for it, so no reading here counts as an exceedance and no utility is required to do anything about it.
Where it comes from: Industrial discharge; solvent stabiliser; contaminated groundwater plumes; a byproduct in some detergents and cosmetics.
The standards
Legal limit (MCL)
No federal limit
Enforceable. A utility must stay at or under this.
Federal health goal (MCLG)
Not set
Health-based, not enforceable. Often lower than the limit, sometimes zero.
EPA reference concentration
0.35 ppb
EPA Reference Concentration (UCMR 3), 2012 Edition of the Health Advisories Table. EPA sets this on a cancer endpoint: it is the level EPA associates with a one in a million lifetime cancer risk. It is not a legal limit and no utility is required to meet it.
Health effects the EPA associates with it: EPA's reference concentration for 1,4-dioxane is based on a cancer endpoint. The figure of 0.35 ppb is the level EPA associates with a one in a million lifetime cancer risk.
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
Ordinary carbon filters do not hold it and it does not strip out by aeration. Advanced oxidation destroys it, which is a plant-scale technology rather than a household one.
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
Miami-Dade County2,986,349 people served6NonePalm Beach County759,168 people served4NoneHillsborough County521,086 people served2NoneBroward County356,266 people served4NoneEscambia County289,578 people served3NonePasco County243,520 people served2NoneSeminole County218,171 people served5NonePolk County212,019 people served2NoneOrange County165,318 people served3NoneBrevard County121,160 people served1NoneOkaloosa County115,084 people served2NoneVolusia County81,006 people served1NoneMartin County43,841 people served2NoneLake County39,279 people served1NoneIndian River County37,308 people served1NonePinellas County28,875 people served1NoneCollier County25,838 people served1NoneCitrus County11,572 people served1NoneMarion County2,923 people served2NoneHighest reported levels
Water systemReadingOf limit
MDWASA - Main SystemMiami · Miami-Dade County0.13 ug/L-Palm Beach County Water UtilitiesWest Palm Beach · Palm Beach County0.18 ug/L-HCPUD/South-CentralLithia · Hillsborough County0.13 ug/L-Emerald Coast Utilities Authority (ECUA)Pensacola · Escambia County0.21 ug/L-Hialeah, City ofHialeah · Miami-Dade County0.094 ug/L-PCUD-Pasco County Regional PWSNew Port Richey · Pasco County0.077 ug/L-Lakeland, City ofLakeland · Polk County0.18 ug/L-North Miami BeachNorth Miami Beach · Miami-Dade County0.078 ug/L-Hollywood, City ofHollywood · Broward County0.071 ug/L-Miramar (East & West) PlantsMiramar · Broward County0.1 ug/L-Palm Bay, City ofPalm Bay · Brevard County0.17 ug/L-Miami Beach, City ofMiami Beach · Miami-Dade County0.098 ug/L-Seacoast Utilities AuthorityPalm Beach Gardens · Palm Beach County0.094 ug/L-North Miami, City ofNorth Miami · Miami-Dade County0.09 ug/L-Deltona WaterDeltona · Volusia County0.072 ug/L-Okaloosa Co.wtr.& Swr.systemFort Walton Beach · Okaloosa County0.08 ug/L-Homestead, City ofHomestead · Miami-Dade County0.34 ug/L-Sanford, City ofSanford · Seminole County0.41 ug/L-Winter Garden Water DeptWinter Garden · Orange County0.2 ug/L-Apopka, City ofApopka · Orange County0.092 ug/L-Lauderhill, City ofLauderhill · Broward County0.13 ug/L-Casselberry, City ofCasselberry · Seminole County0.09 ug/L-University of South FloridaTampa · Hillsborough County0.17 ug/L-Clermont East Water SystemClermont · Lake County0.11 ug/L-Vero Beach, City ofVero Beach · Indian River County0.25 ug/L-Know 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.
