Miami-Dade County tap water: hardness, PFAS and lead
Miami-Dade County, Florida has about 2,838,461 residents (Census 2024 estimate) and 25 community water systems in EPA records. The largest local system is Mdwasa - Main System, serving about 2,377,460 people from groundwater.
✓ 0 of 6 largest systems with health-based violationsPFAS detected at 6 of 6 sampled systemsHardness: test your water
Public-record figures, not a test of your tap. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
How hard is Miami-Dade County water?
Mdwasa - Main SystemNo data: see your utility report · No data
No reliable figure. Test your water.
Miami-Dade's 2025 Water Quality Report says its Main System plants use lime softening to reduce hardness, but it gives no hardness figure. Untreated local stream and well samples would overstate tap hardness, so we don't show a county estimate. Test your water or ask the utility.
Public-record figures, not a test of your tap. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
At this hardness most homes don't need a softener. Confirm with a test strip if you see scale.
Largest water systems in Miami-Dade County
The 6 biggest of 25 community water systems on EPA records for this county. Service areas don't follow county lines; your water bill names your provider.
Mdwasa - Main System
FL4130871 · serves about 2,377,460 people · Groundwater
✓ No health-based violations✓ Lead below action levelPFAS detected (11 types)
Lead 90th percentile: 3.1 ppb (period starting 2023-01-01) Older result. Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
6:2 FTS: highest sample 190 ppt (3 of 8 samples); no federal limit
PFHxA: highest sample 58 ppt (6 of 8 samples); no federal limit
PFPeA: highest sample 56 ppt (6 of 8 samples); no federal limit
PFOS: highest sample 33 ppt (6 of 8 samples); federal limit 4.0 ppt as a running annual average
PFBA: highest sample 22 ppt (6 of 8 samples); no federal limit
PFHpA: highest sample 20 ppt (5 of 8 samples); no federal limit
PFOA: highest sample 14 ppt (6 of 8 samples); federal limit 4.0 ppt as a running annual average
8:2 FTS: highest sample 9.6 ppt (2 of 8 samples); no federal limit
PFHxS: highest sample 9.4 ppt (3 of 8 samples); federal limit 10.0 ppt as a running annual average, also counted in EPA's PFAS mixture (hazard index) limit (currently in effect; EPA has proposed removing it)
PFNA: highest sample 6.5 ppt (2 of 8 samples); federal limit 10.0 ppt as a running annual average, also counted in EPA's PFAS mixture (hazard index) limit (currently in effect; EPA has proposed removing it)
PFBS: highest sample 4.6 ppt (6 of 8 samples); no individual limit; counted in EPA's PFAS mixture (hazard index) limit
FL4130604 · serves about 238,000 people · Groundwater
✓ No health-based violations✓ Lead below action levelPFAS detected (11 types)
Lead 90th percentile: 0.9 ppb (period starting 2025-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
6:2 FTS: highest sample 91.1 ppt (2 of 6 samples); no federal limit
PFPeA: highest sample 36.9 ppt (4 of 6 samples); no federal limit
PFHxA: highest sample 35.2 ppt (4 of 6 samples); no federal limit
PFOS: highest sample 27.6 ppt (4 of 6 samples); federal limit 4.0 ppt as a running annual average
PFBA: highest sample 19.1 ppt (4 of 6 samples); no federal limit
PFHpA: highest sample 14.7 ppt (2 of 6 samples); no federal limit
PFOA: highest sample 10.2 ppt (2 of 6 samples); federal limit 4.0 ppt as a running annual average
PFHxS: highest sample 6.5 ppt (2 of 6 samples); federal limit 10.0 ppt as a running annual average, also counted in EPA's PFAS mixture (hazard index) limit (currently in effect; EPA has proposed removing it)
8:2 FTS: highest sample 5.5 ppt (1 of 6 samples); no federal limit
PFBS: highest sample 5.1 ppt (4 of 6 samples); no individual limit; counted in EPA's PFAS mixture (hazard index) limit
PFNA: highest sample 4.3 ppt (1 of 6 samples); federal limit 10.0 ppt as a running annual average, also counted in EPA's PFAS mixture (hazard index) limit (currently in effect; EPA has proposed removing it)
FL4130901 · serves about 100,000 people · Groundwater
✓ No health-based violations✓ Lead below action levelPFAS detected (10 types)
Lead 90th percentile: 7 ppb (period starting 2025-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
6:2 FTS: highest sample 89 ppt (1 of 2 samples); no federal limit
PFHxA: highest sample 28 ppt (1 of 2 samples); no federal limit
PFPeA: highest sample 27 ppt (1 of 2 samples); no federal limit
PFOS: highest sample 24 ppt (1 of 2 samples); federal limit 4.0 ppt as a running annual average
PFBA: highest sample 15 ppt (1 of 2 samples); no federal limit
PFHpA: highest sample 11 ppt (1 of 2 samples); no federal limit
PFOA: highest sample 7.8 ppt (1 of 2 samples); federal limit 4.0 ppt as a running annual average
PFHxS: highest sample 5.6 ppt (1 of 2 samples); federal limit 10.0 ppt as a running annual average, also counted in EPA's PFAS mixture (hazard index) limit (currently in effect; EPA has proposed removing it)
8:2 FTS: highest sample 5.3 ppt (1 of 2 samples); no federal limit
PFBS: highest sample 3.5 ppt (1 of 2 samples); no individual limit; counted in EPA's PFAS mixture (hazard index) limit
FL4130977 · serves about 89,349 people · Groundwater
✓ No health-based violations✓ Lead below action levelPFAS detected (9 types)
Lead 90th percentile: 1.8 ppb (period starting 2023-01-01) Older result. Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
PFOS: highest sample 45 ppt (4 of 4 samples); federal limit 4.0 ppt as a running annual average
PFPeA: highest sample 24 ppt (4 of 4 samples); no federal limit
PFBS: highest sample 21 ppt (3 of 4 samples); no individual limit; counted in EPA's PFAS mixture (hazard index) limit
PFHxA: highest sample 21 ppt (4 of 4 samples); no federal limit
6:2 FTS: highest sample 20 ppt (4 of 4 samples); no federal limit
PFBA: highest sample 13 ppt (4 of 4 samples); no federal limit
PFOA: highest sample 12 ppt (2 of 4 samples); federal limit 4.0 ppt as a running annual average
PFHxS: highest sample 8.6 ppt (2 of 4 samples); federal limit 10.0 ppt as a running annual average, also counted in EPA's PFAS mixture (hazard index) limit (currently in effect; EPA has proposed removing it)
PFHpA: highest sample 8 ppt (4 of 4 samples); no federal limit
FL4134357 · serves about 86,000 people · Groundwater
✓ No health-based violations✓ Lead below action levelPFAS detected (8 types)
Lead 90th percentile: 4 ppb (period starting 2023-01-01) Older result. Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
PFOS: highest sample 50.3 ppt (2 of 2 samples); federal limit 4.0 ppt as a running annual average
PFBS: highest sample 22.8 ppt (2 of 2 samples); no individual limit; counted in EPA's PFAS mixture (hazard index) limit
PFBA: highest sample 10.2 ppt (2 of 2 samples); no federal limit
PFOA: highest sample 9.9 ppt (2 of 2 samples); federal limit 4.0 ppt as a running annual average
PFPeA: highest sample 4 ppt (2 of 2 samples); no federal limit
PFHxS: highest sample 3.4 ppt (1 of 2 samples); federal limit 10.0 ppt as a running annual average, also counted in EPA's PFAS mixture (hazard index) limit (currently in effect; EPA has proposed removing it)
PFHxA: highest sample 3.3 ppt (1 of 2 samples); no federal limit
PFHpA: highest sample 3.3 ppt (1 of 2 samples); no federal limit
Public-record figures, not a test of your tap. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
A PFAS detection is not a violation. Federal limits (4 ppt for PFOA and PFOS) apply to running annual averages, with compliance required by 2029. In May 2026 EPA proposed extending the PFOA/PFOS deadline to 2031 and removing other PFAS limits; not final as of 2026-10-21.
Test your own tap
These are public records for whole systems. Your home's pipes, fixtures and any private well can change what you drink. A certified lab test or a hardness test strip gives you your own numbers. Then use our PFAS and lead filter selector to see which certifications to look for.
Common questions about Miami-Dade County water
Is tap water in Miami-Dade County safe to drink?
None of the 6 largest systems here have a health-based violation in EPA records since October 2021. Mdwasa - Main System's most recent lead 90th percentile was 3.1 ppb (2023), below the 15 ppb action level. Public records can't guarantee what comes out of your tap, especially with older plumbing, so a home test is the surest check.
How hard is the water in Miami-Dade County?
We don't have a reliable hardness figure for Mdwasa - Main System, so test your water or check its annual water quality report.
Is there PFAS in Miami-Dade County water?
6 of the 6 sampled systems listed here detected at least one PFAS in EPA's UCMR 5 testing, and 12 results were above the level of a federal limit in at least one sample. A detection isn't a violation: federal PFAS limits apply to running annual averages starting in 2029.
Which water system serves my address in Miami-Dade County?
Most homes are served by Mdwasa - Main System or one of the other systems listed on this page, but service areas don't follow county lines. Your water bill names your provider, and its annual Consumer Confidence Report has the full test results.
Data as of October 21, 2026. Figures are copied from public records and combined with our own calculations; they can be out of date or wrong. Tapped Out isn't affiliated with any utility or the EPA. Written and reviewed by the Tapped Out team. How we calculate · All sources.