MIAMI DRINKING WATER

Miami-Dade County’s drinking water is primarily supplied by the Miami-Dade Water and Sewer Department (WASD), which serves roughly 2.3–2.8 million people. Official annual Consumer Confidence Reports (CCRs / Water Quality Reports) consistently state that the water meets or exceeds all applicable local, state, and federal standards.

Water Supply Sources and Treatment

• Primary source: Groundwater from the Biscayne Aquifer (shallow, highly permeable limestone aquifer). Wells typically extend about 80 feet deep. This supplies the vast majority of drinking water.
• Secondary/limited source: Deeper Floridan Aquifer (brackish water), treated with reverse osmosis (e.g., Hialeah RO plant, capacity around 7.5 MGD shared with the city of Hialeah).
• Major treatment plants include Alexander Orr Jr., Hialeah, and John E. Preston (main system), plus smaller South Dade plants.

Typical treatment process (main plants drawing from Biscayne Aquifer):

• Lime softening (to reduce hardness; enhanced softening at some plants for higher organics).
• Sedimentation.
• Dual-media filtration (sand/anthracite).
• Primary disinfection with chlorine, followed by ammonia to form chloramines (longer-lasting residual in the distribution system).
• Fluoridation (historically; note a 2025 County Commission vote to remove fluoride addition, with implementation steps following).
• Corrosion control (phosphorus compound) and pH adjustment.
• Air stripping at Hialeah and Preston plants to remove volatile organic compounds.
• Annual temporary free-chlorine conversion (typically 1–2 weeks) for system cleaning/maintenance, which can cause temporary chlorine taste/odor or cloudy water.

WASD conducts more than 150,000 samples and analyses per year.

Drinking Water Quality and Test Results

Official 2024 and 2025 Water Quality Reports (covering prior-year testing) report no Maximum Contaminant Level (MCL) violations. Key highlights from the 2024 data (similar patterns in prior years):

• Microbiological: Total coliform typically zero or well within limits.
• Disinfection byproducts: Total Trihalomethanes (TTHMs) averages around 50–51 ppb (range varies by system; MCL 80 ppb). Haloacetic acids (HAAs) also below limits.
• Inorganics: Fluoride, nitrate, and others well below MCLs.
• Lead and copper (at-the-tap sampling): 90th percentile values generally low; occasional individual home exceedances attributed to household plumbing. Corrosion control is applied.
• PFAS (emerging contaminants): Low-level detections (e.g., PFOS, PFOA in the tens of ppt range in some systems). Hazard Index values generally low; monitoring continues ahead of new federal rules (compliance timelines extending into the late 2020s).
• Other parameters (radionuclides, organics, etc.): Non-detect or below standards.

Independent aggregators sometimes highlight detections above health goals (stricter than MCLs) or historical process/paperwork issues, but official utility and regulatory reports emphasize full compliance with enforceable standards.

Saltwater Intrusion

This is a long-standing and ongoing challenge for the Biscayne Aquifer due to its coastal location, high permeability, historical drainage of the Everglades (which lowered freshwater heads), canal management, over-pumping, and sea-level rise.

• USGS mapping shows the saltwater interface (defined by the ~1,000 mg/L chloride isochlor at the base of the aquifer) continued to advance inland between 2018 and 2022 — by as much as ~0.3 km in northern areas and up to ~0.8 km in southern Model Land areas, while remaining relatively stable in east-central zones.
• Coastal wells have been abandoned or relocated farther inland over decades. Continuous monitoring networks track the interface.
• Additional concerns include saline leakage from canals and a documented saline plume associated with the Turkey Point nuclear plant cooling canals.
• Long-term risks include reduced freshwater storage and potential need for more costly alternative supplies (expanded RO, reclaimed water, etc.).

Drinking Water Challenges and Complaints

Major challenges include saltwater intrusion/sea-level rise pressures, nutrient and pathogen risks from the large number of remaining septic systems (~112,000–120,000 residential), aging infrastructure, drought-related water shortage warnings, and emerging contaminants like PFAS.

Resident complaints (from news, BBB, and local reports) more commonly involve:

• Temporary cloudy, turbid, or yellowish water (often linked to main breaks, system flushing, or the annual chlorine conversion).
• Localized pressure or service interruptions.
• High bills in some municipalities.
• Occasional reports of taste/odor.

These are typically addressed as localized or temporary issues rather than systemic quality failures. Official reports do not indicate widespread unsafe water.

Projects Requiring Well/Septic Abandonment and Hookup Costs

Connect 2 Protect is the major countywide septic-to-sewer conversion initiative (launched ~2022). It prioritizes vulnerable areas (sea-level rise, high groundwater, proximity to waterways) to reduce aquifer and Biscayne Bay contamination risks. Public infrastructure expansion is underway with significant funding (hundreds of millions secured; total multi-year costs in the billions).

• Homeowners with abutting sewer infrastructure typically face private-side costs (lateral, plumbing modifications, septic abandonment) in the roughly $10,000–$20,000+ range (highly variable by distance, site conditions, rock excavation, etc.). Public-side costs are separate.
• Financial assistance: Eligible homesteaded properties can receive up to $15,000 via grants, 0% interest loans, or low-interest loans (income-based, first-come/first-served). Septic abandonment (pump-out, fill, permits) is required. Conversion of a private well to municipal water is not automatically required when connecting to sewer.
• Broader estimates for full conversion projects often cite $3,000–$20,000+ for homeowners before assistance; longer laterals or difficult sites cost more.

When sewer becomes available, connection is typically required within a set timeframe under local rules.

Frequency of Boil Water Notices

System-wide or frequent county-wide boil water notices are uncommon. Most are localized and precautionary, issued after water main breaks, pressure loss, or similar events (e.g., portions of Hialeah in 2024). They generally last a few days until bacteriological testing clears the area.

Recreational beach/waterway advisories (bacteria) occur more regularly but are separate from drinking water.

Bottom line: Official testing shows Miami-Dade’s treated drinking water meets regulatory standards. The biggest structural risks are long-term saltwater intrusion into the Biscayne Aquifer and contamination pathways from remaining septic systems—both of which drive ongoing infrastructure projects and monitoring. For the absolute latest data, check the current WASD Water Quality Report (CCR) on the Miami-Dade County website or contact WASD directly, as conditions and projects evolve.