Rotten-egg smell in Southwest Florida water

What the smell is

Hydrogen sulfide is the gas that smells like rotten eggs. In household water it is handled as an aesthetic problem: the odor itself, and sometimes tarnish or a dark stain. People notice the gas at very low levels, so a strong impression can still be a modest amount in the water.

The smell is a clue about the gas. A coliform test is how you check bacteria. Ask for that test on a private well when sulfur is the reason you called.

A strong sulfur smell in a closed well pit or well house is a reason to stay out. The gas can collect in a tight space. Leave that entry to someone equipped for it.

This page is practical guidance from the directory team for Lee, Collier, and Charlotte counties.

Hydrogen sulfide from the well

Groundwater in Southwest Florida can carry hydrogen sulfide where the water has been out of contact with air. When the cold water smells, the hot water smells too, because the heater draws that same water. Sulfur bacteria in the well, the pressure tank, or the pipes can make the same gas, sometimes with a slime.

Smell alone cannot sort out other causes. Pair the sulfur check with coliform bacteria and nitrate on a private well.

The water-heater anode

Cold water that smells fine, and hot water that smells like rotten eggs, points at the heater before a whole-home system. A magnesium anode rod can react with sulfate in the water and produce hydrogen sulfide inside the tank, especially when hot water sits unused.

Switching the anode metal, flushing the tank, or both, is ordinary heater service. Leave the rod, the tank, and the thermostat to a plumber or a water-treatment company so the job stays clear of scalding and tank damage.

A heater can add to a smell that is already in the cold water. When both sides smell, heater service may be only part of the fix.

Testing

Write down which taps smell, and whether it is the hot water, the cold water, or both. Note whether the smell is new.

Hydrogen sulfide leaves a water sample quickly. A bottle that waits on the counter can understate it. Ask the laboratory or the tester whether the sulfur check has to happen on site.

On a private well, add coliform bacteria and nitrate. Iron, hardness, pH, and tannins change which sulfur method works, so include them on the same visit when you can. On city water, ask the utility whether neighbors have the same smell. A hot-only smell can still be the heater.

Treatment

Match the method to where the smell starts and to the test.

Aeration mixes air into the water so hydrogen sulfide can leave as a gas. That gas needs an outdoor vent, away from living space and away from a well pit. Aeration fits where that vent is practical.

Oxidation turns the gas into a form filtration can catch. Chlorine, hydrogen peroxide, and oxidizing filter media are the approaches companies compare. Iron can come out in the same step, which is why the iron result matters. Chemical feed needs a maintenance plan, including where any backwash goes.

Activated carbon can take a light sulfur smell. The carbon fills up and has to be replaced. A strong or steady smell calls for oxidation rather than a cartridge alone. Carbon that also strips chlorine from utility water needs to be changed on a schedule.

When sulfur bacteria are established in the well, well disinfection may be part of the work, with a longer-term system if the smell returns. That belongs with a well or treatment company, followed by another bacteria test.

A softener is the tool for hardness. Hydrogen sulfide needs one of the steps above. Reverse osmosis on a kitchen tap leaves showers and hose bibs on the untreated water. When the smell is only in the hot water, service the heater and smell it again before you price a whole-home system.

Our team can take a quote request once you know whether the smell is in the cold water, the hot water, or both. Share that detail. Listings show the services a business reports, separate from independent verification.

LISTINGS

Companies that list these services

Each link opens the provider list filtered to a recorded category. Confirm the service, the service area, and the test method with the company. Water testing has its own category. If that list is empty, ask a well or filtration company whether they test, and send bacteria samples to a drinking-water laboratory either way.

• Water testing. Ask for an on-site sulfur check when the sample would otherwise sit, and pair it with a bacteria test on a private well.
• Water filtration. Aeration, oxidation, and carbon are quoted with filtration companies.
• Well-water systems. When the cold water smells, the well and the treatment at the well are the place to start.
• Repair and maintenance. A hot-only smell points to the water heater, which is service work ahead of a new whole-home system.

NEXT STEP

Get a free water test / quote

Tell our team what you are noticing. The form asks about the water first. Your name and a phone number or email come only if you continue, and the consent on that step names who may call or text.

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