How does South Miami's water compare to the national average?

The USA national average is 151 mg/L. South Miami (≈ 120–179 mg/L) is 1 mg/L softer than average.

South Miami Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

groundwater

pH Level

8.5

neutral = 7.0

Lead

0.006 mg/L

✓ Below action level

TDS

749.7 mg/L

Est. Daily Cost

$0.40

energy & soap waste

Source: See methodology section below · Updated 2026

hard~120–179 mg/LHard · est.

0–60

mg/L

Soft

61–120

mg/L

Moderately Hard

121–180

mg/L

Hard

180+

mg/L

Very Hard

Appliance Damage Report

In South Miami, your appliances are currently losing 20% efficiency due to mineral buildup.

Appliance	In South Miami	Soft Water City	Efficiency Loss
Kettle	6.8 yrs	8.5 yrs	-20%
Washing Machine	9.6 yrs	12 yrs	-20%
Water Heater	12 yrs	15 yrs	-20%

Regional Water Comparison

How South Miami compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ South Miami, Florida	≈ 120–179 mg/L	10.4 ppt	🟠 Hard	groundwater
Coral Gables, Florida	≈ 180+ mg/L	7.3 ppt	🔴 Very Hard	groundwater
Glenvar Heights, Florida	≈ 120–179 mg/L	6.7 ppt	🟠 Hard	groundwater
Coconut Grove, Florida	≈ 120–179 mg/L	6 ppt	🟠 Hard	groundwater
Kendall, Florida	≈ 120–179 mg/L	10.7 ppt	🟠 Hard	groundwater

National Benchmark

How South Miami compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ South Miami	≈ 120–179 mg/L	🟠 Moderate
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes South Miami's Water Unique?

Local geology and source profile

Source: GroundwaterTDS: 749.7 mg/LpH: 8.5

South Miami, Florida gets its drinking water from the Miami-Dade Water and Sewer Department (WASD). The main source is the Biscayne Aquifer, a shallow underground water source tapped by numerous wellfields, including Hialeah and Northwest Wells. This raw water is then processed at treatment facilities like the Alexander Orr Jr. Water Treatment Plant and the Hialeah Water Treatment Plant. The utility conducts extensive annual testing, analyzing over 100,000 water samples to confirm it meets federal safety standards. Rainfall replenishes the Biscayne Aquifer, seeping through the porous limestone bedrock in areas ranging from the Everglades watershed to urban environments.

The Biscayne Aquifer is a significant geological feature of South Florida. It's primarily composed of Pleistocene-era carbonate rocks, specifically the Miami Limestone and the Fort Thompson Formation. These formations are oolitic limestones, meaning they are packed with calcium carbonate. As acidic rainwater interacts with this bedrock, it dissolves, releasing calcium and magnesium into the groundwater. This natural process, typical of limestone-dominated regions, results in water that is moderately hard.

Homeowners in South Miami may notice moderate scale buildup on faucets and showerheads, which can also leave spots on glassware. This mineral content can affect the efficiency of appliances like coffee makers and water heaters over time. To manage scale, try using vinegar to clean fixtures or consider installing low-flow showerheads. For a more comprehensive solution, especially for laundry and bathing, a whole-home water softener or filtration system could reduce soap scum and prevent clothes from feeling stiff. While the Miami-Dade WASD water is safe, older plumbing in some buildings might pose a risk of lead contamination, and the water can have a slight yellowish tint from tannins. The treatment process, including filtration and chemical adjustments, aims to provide a neutral to slightly alkaline water, with disinfection by chlorine and chloramine.

Geology & Source: Biscayne Aquifer; Pleistocene oolitic limestone (Miami Limestone, Fort Thompson Formation) rich in calcium carbonate dissolves to impart moderate hardness

Other Florida Water Reports

Coral Gables

≈ 180+ mg/L

🔴 Very Hard

Glenvar Heights

≈ 120–179 mg/L

🟠 Hard

Coconut Grove

≈ 120–179 mg/L

🟠 Hard

Kendall

≈ 120–179 mg/L

🟠 Hard

Report an Issue

Notice an error or missing data? Help us keep this page accurate. If you spot incorrect water hardness, outdated utility info, or missing details, please let us know.

All reports are reviewed by our team. Thank you for supporting data quality!

Frequently Asked Questions

Is South Miami's water safe to drink?

Yes. South Miami's water meets all federal safety standards. The hardness is ≈ 120–179 mg/L (Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.

Do I need a water softener in South Miami?

At ≈ 120–179 mg/L (Hard), South Miami's water will cause significant limescale on kettles, washing machines, and water heaters. A water softener or descaler is strongly recommended to extend appliance lifespan and reduce energy bills by up to 20%.

How does South Miami compare to the USA average?

The USA national average is 151 mg/L. South Miami (≈ 120–179 mg/L) is 1 mg/L below the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for South Miami is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.

Estimated

Water Hardness

Modelled estimate based on state-level USGS geological survey data for this region. No direct USGS Water Quality Portal measurement was matched to this city — the value reflects a statistical range calibrated to the state's dominant rock types and typical source water characteristics.

Estimated

Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.

Estimated

TDS — Total Dissolved Solids

Estimated using a derived ratio from water hardness and regional conductance profiles. TDS in natural water correlates strongly with total mineral content including hardness ions.

Measured

PFAS — Perfluoroalkyl and Polyfluoroalkyl Substances

EPA UCMR5 (5th Unregulated Contaminant Monitoring Rule, 2023–2025) — sum of PFAS compounds detected at the public water system serving this city. A value of 0 indicates the system was sampled with no detection above reporting limits.

Modelled

Lead

Modelled estimate based on the EPA Lead and Copper Rule 90th-percentile tap-sample methodology. No publicly available per-city lead dataset with sufficient national coverage exists. Values are a conservative baseline derived from city population tier and infrastructure age — all estimates are maintained below the EPA action level of 0.015 mg/L.

Calculated

Appliance Lifespan

Calculated from water hardness using a linear degradation model. Baseline lifespans represent soft-water performance (kettle: 8.5 yrs, washing machine: 12.0 yrs, water heater: 15.0 yrs). Hard water mineral scale progressively reduces operational life in direct proportion to hardness concentration.