Water Smells Like Rotten Eggs in Miami

Start with the hot-and-cold sniff test

The Florida Department of Health's well water fact sheet on odor and staining lays out a simple way to locate the source. Run each tap and smell the water:

• Hot tap only: the problem is most likely inside the water heater.
• Hot and cold, but only on water that passes through a softener: sulfur bacteria may be living in the softener.
• Strong at first, then fading as the water runs: likely sulfur bacteria in the well or plumbing.
• Strong and steady no matter how long it runs: likely hydrogen sulfide in the groundwater feeding the well.

Most Miami houses are on WASD city water, so the first result on that list is the one Jorge sees most often inside the city.

Why a Miami water heater can start to smell

Tank water heaters contain a metal rod, called an anode, that corrodes on purpose to protect the tank. Under some conditions that reaction, along with bacteria that thrive in warm stagnant water, produces hydrogen sulfide. The DOH fact sheet notes that chemical reactions inside water heaters can be a source of the smell.

Things that make it more likely:

• A vacation home or seasonal condo where the heater sits unused for weeks.
• A thermostat set low.
• An older tank that has never been flushed.

A plumber or the water heater manufacturer can advise on flushing the tank or changing the anode type. That is a water heater fix, not a filtration problem, and Jorge will tell you so if that is what the test points to.

When the smell is in the water itself

WASD pulls Miami's water from the Biscayne Aquifer and treats it at the Hialeah, John E. Preston and Alexander Orr, Jr. plants before it reaches you, so a steady sulfur odor from every cold tap is unusual on city water. If you notice one, call WASD's water quality lines listed in its annual report (786-552-4738 for the Hialeah and Preston plants, 786-552-4181 for the Orr plant) so the utility knows.

Private wells are a different story. The DOH says hydrogen sulfide can occur in wells anywhere in Florida. Some Miami-area properties also run a separate irrigation well for the yard, and that water can smell strongly of sulfur when the sprinklers run even though the house water is fine.

Treatment options when the source is a well

Once a test confirms hydrogen sulfide in well water, the common approaches are:

• Aeration: air is mixed with the water so the gas is released and vented away.
• Oxidation: an oxidizer converts the odor compounds so they can be filtered out.
• Adsorption: activated carbon captures odor compounds at lower levels.

Which one fits depends on how strong the smell is and what else is in the water, such as iron. Living Water configures well water systems from the well's own test. For a side-by-side look, see aeration vs. filtration for sulfur smells.

What Jorge checks during a free visit

1. Which taps smell, hot, cold or both, and whether a softener or filter is already installed.
2. Whether you are on WASD water, a private well, or city water plus an irrigation well.
3. A test of the water at your tap so the recommendation matches the cause.

If the answer is a water heater issue, you will hear that plainly. Call, text or WhatsApp (305) 793-5974 to book.

Updated 2026-10-17 · Living Waters · Jorge Canela, Water Quality Specialist