Where the water comes from — and what comes with it — in Orlando tap water

Water in Orlando and the surrounding area comes from the Floridan Aquifer, one of the largest underground water reserves in the world. It is naturally filtered through limestone layers before being captured and treated by local utilities (OUC and Orange County Utilities), which disinfect with chlorine, adjust pH, and distribute the water.

That limestone explains the first striking characteristic of our water: hardness.

Water in the Orlando area is classified as “hard” to “extremely hard” — public measurements range from 129 to 190 ppm, reaching 17.2 grains per gallon (GPG) in areas served by Orange County Utilities. For comparison: above 10.5 GPG is considered “very hard” by the USGS scale.

What hard water causes in practice:

• White spots on dishes, shower walls and faucets (calcium and magnesium buildup)
• Scale buildup inside water heaters, dishwashers and washing machines, reducing appliance lifespan
• Dry skin and hair — minerals react with soap and leave residue on skin and hair
• Rougher, faster-fading clothes
• Higher consumption of soap and detergent

Chlorine is necessary to eliminate microorganisms — but when it reacts with natural organic matter in the water, it forms disinfection byproducts (DBPs), mainly trihalomethanes (TTHMs) and haloacetic acids (HAA5). The EPA associates prolonged exposure to DBPs with increased risks of bladder cancer and kidney and liver problems.

The numbers in our region:

It is important to be fair: OUC says it follows all EPA and Florida Department of Environmental Protection limits — and that is true. The question each family decides is: do I want to live at legal limits, or below them?

• TTHM measurements in the Orlando area have reached 97 ppb — above the EPA legal limit of 80 ppb (source: Hydroviv, based on utility data)
• HAA5 reached 53.3 ppb, close to the legal limit of 60 ppb
• EWG analysis showed that HAA9 levels in OUC water were hundreds of times above the EWG health guideline, which uses stricter references than EPA legal limits that have not been updated for about two decades

Florida banned lead plumbing in the 1980s, and treated water leaves the plants without known lead levels. The risk is in the path: homes built before the mid-1980s can have lead pipes and solder joints that contaminate the water inside the house.

The EPA and the AAP (American Academy of Pediatrics) say there is no safe level of lead for children.

• OUC analysis found a concentration of 3 ppb at the 90th percentile; Orange County Utilities measurements have recorded as much as 7.89 ppb
• The EPA and the AAP say there is no safe level of lead for children

PFAS (“forever chemicals”) are present in the water of more than 143 million Americans, according to the EWG database. They are associated with effects on the immune and hormonal systems and some types of cancer.

The EPA published the first federal limits for PFAS in drinking water in 2024, with compliance deadlines for utilities throughout this decade — in other words, this is an evolving issue, and RO systems with suitable membranes already remove most of these substances today.