Water Quality Report · Updated May 12, 2026
MDWASA - MAIN SYSTEM
MDWASA - MAIN SYSTEM delivers tap water graded F (51/100) by TapWaterSafety.org. The utility serves approximately 2,377,460 residents in MIAMI, Florida using groundwater. The most significant water quality concerns are: PFAS contamination; Perfluorohexane sulfonate (PFHXS) significantly above health guideline; Haloacetic acids (HAA9) significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline; Arsenic detected. For questions, the utility can be reached at 786-552-8112.
Is MIAMI tap water safe to drink?
MDWASA - MAIN SYSTEM delivers tap water that earns a grade of F (51/100) from TapWaterSafety.org — a poor rating, with significant contamination concerns and/or recent violations.
The utility serves 2,377,460 residents in MIAMI, drawing from groundwater.
Public testing data identifies 20 contaminants in this water above EWG's health-based guidelines, including: Perfluorooctanoic acid (PFOA), Perfluorooctane sulfonate (PFOS), Perfluorohexane sulfonate (PFHXS), Haloacetic acids (HAA9), Haloacetic acids (HAA5), Total trihalomethanes (TTHMs), Perfluorononanoic acid (PFNA), Bromodichloromethane, Dibromoacetic acid, Arsenic, Dichloroacetic acid, Trichloroacetic acid, Chloroform, Dibromochloromethane, 6:2 Fluorotelomer Sulfonic Acid (6:2 FTSA), Chromium (hexavalent), Radium, combined (-226 and -228), Uranium, 8:2 Fluorotelomer Sulfonic Acid (8:2 FTSA), Bromoform. For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
Quick actions for MIAMI residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for MDWASA - MAIN SYSTEM.
PFAS contamination
Severe concernPerfluorononanoic acid (PFNA), Perfluorooctane sulfonate (PFOS) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Perfluorohexane sulfonate (PFHXS) significantly above health guideline
Moderate concernPerfluorohexane sulfonate (PFHXS) detected at 1.77 ppt, 1771x above the EWG health guideline of 0.001 ppt.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 37.6 ppb, 627x above the EWG health guideline of 0.06 ppb.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 29.0 ppb, 290x above the EWG health guideline of 0.1 ppb.
Arsenic detected
Moderate concernArsenic detected at 0.5 ppb.
Contact MDWASA - MAIN SYSTEM
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for MIAMI
Filters matched to the specific contaminants in this water supply.
Reverse Osmosis or NSF P473 certified carbon
$80-$750Activated carbon and RO are the only technologies proven to remove PFAS at certified levels.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
Reverse Osmosis
$249-$750Arsenic is most effectively removed by reverse osmosis. Some specialized adsorptive filters also work.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
Score breakdown
This utility's overall score of 51/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Perfluorooctanoic acid (PFOA) PFAS |
4.64 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | EPA violation |
| Perfluorooctane sulfonate (PFOS) PFAS |
12.0 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | EPA violation |
| Perfluorohexane sulfonate (PFHXS) PFAS |
1.77 ppt | 0.001 | 10.0 | — | — | — | — | 1771× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
37.6 ppb | 0.06 | — | — | — | — | — | 627× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
29.0 ppb | 0.1 | 60.0 | 60 | — | — | — | 290× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
32.0 ppb | 0.15 | 80.0 | 100 | — | — | — | 214× over |
| Perfluorononanoic acid (PFNA) PFAS |
0.929 ppt | 0.006 | 10.0 | — | — | — | — | 155× over |
| Bromodichloromethane Disinfection byproduct |
8.59 ppb | 0.06 | — | — | — | — | — | 143× over |
| Dibromoacetic acid Disinfection byproduct |
3.85 ppb | 0.03 | — | — | — | — | — | 128× over |
| Arsenic Heavy metal |
0.5 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 125× over |
| Dichloroacetic acid Disinfection byproduct |
18.0 ppb | 0.2 | — | — | — | — | — | 90× over |
| Trichloroacetic acid Disinfection byproduct |
5.34 ppb | 0.1 | — | — | — | — | — | 53× over |
| Chloroform Disinfection byproduct |
18.3 ppb | 0.4 | — | — | — | — | — | 46× over |
| Dibromochloromethane Disinfection byproduct |
4.62 ppb | 0.1 | — | — | — | — | — | 46× over |
| 6:2 Fluorotelomer Sulfonic Acid (6:2 FTSA) Other |
28.3 ppt | 1.0 | — | — | — | — | — | 28× over |
| Chromium (hexavalent) Heavy metal |
0.0857 ppb | 0.02 | — | — | — | — | — | 4.3× over |
| Radium, combined (-226 and -228) Radiological |
0.12 pCi/L | 0.05 | 5.0 | — | — | — | — | 2.4× over |
| Uranium Radiological |
0.54 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 1.3× over |
| 8:2 Fluorotelomer Sulfonic Acid (8:2 FTSA) Other |
1.17 ppt | 1.0 | — | — | — | — | — | 1.2× over |
| Bromoform Disinfection byproduct |
0.554 ppb | 0.5 | — | — | — | — | — | 1.1× over |
| Chlorate Disinfection byproduct |
154.2 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Nitrate Inorganic |
0.0808 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | Below guideline |
| 1,4-Dioxane Semi-volatile organic compound |
0.0433 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Molybdenum Other |
2.47 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
0.937 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
1.59 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Aluminum Heavy metal |
10.1 ppb | 600.0 | — | 200 | — | 600 | — | Below guideline |
| Barium Heavy metal |
10.0 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Perfluoropentanoic Acid (PFPeA) PFAS |
13.7 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
12.2 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Selenium Heavy metal |
0.333 ppb | 30.0 | 50.0 | 20 | 40 | 30 | — | Below guideline |
| Monobromoacetic acid Disinfection byproduct |
0.274 ppb | 25.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
1.09 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Perfluorobutanoic Acid (PFBA) PFAS |
8.97 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluoroheptanoic acid (PFHPA) PFAS |
4.43 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
2.91 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.322 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Chlorodifluoromethane Other |
0.152 ppb | — | — | — | — | — | — | Below guideline |
| Chromium (total) Heavy metal |
0.167 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.654 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Nitrite Inorganic |
0.0457 ppm | — | 1.0 | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
MDWASA - MAIN SYSTEM service area
This water system serves 1 community in Miami-Dade County, Florida. Click any city for its dedicated tap water quality page.
Find the right filter for MIAMI water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.