Is there PFAS in Mdwasa - Main System water?
Yes. EPA's final UCMR 5 results show Mdwasa - Main System averaged 31.4 ppt of PFOS at its worst sampling point, 7.8 times the EPA limit of 4 ppt.
Mdwasa - Main System
Serves 2.4 million people · 8 PFOA samples from 4 sampling points · Nov 2023 to May 2024
Average above an EPA limit
PFOA Perfluorooctanoic acid
12.3 ppt avg · max 14.0
PFOS Perfluorooctanesulfonic acid
31.4 ppt avg · max 33.0
PFHxS Perfluorohexanesulfonic acid
8.8 ppt avg · max 9.4
PFNA Perfluorononanoic acid
5.6 ppt avg · max 6.5
Hazard index GenX, PFBS, PFNA, PFHxS combined
1.4 avg · max 1.6
Also detected, no federal limit: 6:2 FTS, PFHxA, PFPeA, PFBA, PFHpA, 8:2 FTS, PFBS.
Mdwasa - Main System is a public water system drawing on groundwater, based in Miami, Florida, serving about 2.4 million people, including Homestead, Miami, Miami Beach, Key Biscayne, North Miami Beach. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 8 times across 4 sampling points between Nov 2023 and May 2024.
Every PFAS detected
Not detected: PFPeS, PFEESA, PFMBA, PFMPA, 4:2 FTS, HFPO-DA, ADONA, 9Cl-PF3ONS, PFHpS, PFUnA, PFTA, PFDoA, PFDA, NFDHA, NMeFOSAA, NEtFOSAA, PFTrDA, 11Cl-PF3OUdS.
Lithium, tested in the same program: not detected.
What the EPA limits mean here
In April 2024 EPA set enforceable limits of 4 ppt for PFOA and PFOS, 10 ppt each for PFHxS, PFNA and GenX, and a hazard index of 1 for mixtures. Utilities were given until 2029 to comply. In May 2026 EPA proposed keeping only the PFOA and PFOS limits and moving that deadline to 2031. Until that proposal is final, the 2024 limits stand.
Compliance is judged on a running annual average at each entry point, so we show the average at this system's worst sampling point next to its single highest result. UCMR 5 results do not by themselves put a utility in or out of compliance.
What you can do at home
Two routes work for PFAS. For drinking and cooking water only, a reverse osmosis system certified to NSF/ANSI 58 with a PFOA/PFOS reduction claim is the cheapest proven option. To treat every tap and shower, a whole-house carbon system with enough contact time works, but check that the maker has PFAS test data, not just a marketing claim. See the best filters for PFAS and how PFAS removal works.
Other systems in Florida
All 409 tested systems in Florida
ZIP codes served
33031 33032 33033 33101 33109 33116 33122 33125 33126 33127 33128 33129 33130 33131 33132 33133 33134 33135 33136 33137 33138 33139 33140 33141 33142 33143 33144 33145 33146 33147 33149 33150 33151 33152 33153 33154 33155 33156 33157 33158 33160 33161 33162 33165 33166 33167 33168 33169 33170 33172 33173 33174 33175 33176 33177 33178 33179 33180 33181 33182 33183 33184 33185 33186 33187 33189 33190 33192 33193 33194 33196 33197 33283
As reported by the utility to EPA. Neighbouring ZIPs are often split between systems; your water bill names yours.
Cite this page
Well & Tap. "PFAS in Mdwasa - Main System water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID FL4130871. https://wellandtap.com/pfas/florida/mdwasa-main-system/
About this data
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID FL4130871). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.
