NMB Water's own rule of thumb
NMB Water's website gives a simple way to find an odor's source. If the public supply were the cause, you would smell it at every faucet, all the time. If you only notice it at one or a few faucets, the source is in your plumbing. Its guidance also says sink drains are a common source of odors from bacterial growth, and that if only the hot water smells, the water heater is the place to look.
Match the smell to the source
| What you notice | Most likely cause |
|---|---|
| Hot taps only, worse in the morning or after a trip | Tank water heater and its anode rod |
| One sink, smell near the drain | Bacteria in the drain, not the water |
| Every tap, hot and cold, on a well | Hydrogen sulfide in the groundwater |
| Around sprinklers, wet walls or pavers | Irrigation water from a well |
| Chlorine-like, not eggy, for a couple of weeks | NMB's annual temporary switch to free chlorine |
A quick check: fill a glass from the cold tap and take it to another room before smelling it. If the glass does not smell, the drain is the likely culprit.
The water heater explanation
Most tank water heaters have a sacrificial anode rod, often magnesium, to slow corrosion of the tank. In some conditions, bacteria in warm water that sits for days react with the rod and give off hydrogen sulfide. That is why seasonal homes and rarely used guest bathrooms often have the worst smell. Flushing the tank, or having a plumber change the rod type, usually fixes it. Check the heater manufacturer's guidance first, since rod changes can affect the warranty.
NMB's 2025 Water Quality Report also recommends flushing the water heater and household plumbing at least twice a year when discolored water is a problem, a habit that helps with odor too.
Wells and irrigation water
The Biscayne Aquifer under North Miami Beach is shallow, porous limestone about 10 to 200 feet down, according to NMB Water. Water pulled straight from it for sprinklers gets no treatment, and it can carry hydrogen sulfide and iron. Miami-Dade's year-round irrigation restrictions apply to private wells as well as utility water. For a drinking-water well, treatment is chosen from the well's test, often aeration or oxidation followed by filtration. See aeration vs. filtration for sulfur smells and well water in North Miami Beach.
What Jorge checks
Hot and cold at several taps, chloramine, pH and iron, the water heater's age and type, and how often each bathroom is used. If the heater or a drain is the cause, he will tell you, and you may not need a filter at all. Call, text or WhatsApp (305) 793-5974.
https://www.citynmb.com/915/Source-of-Odor
https://www.citynmb.com/918/Odor-from-My-Tap
https://www.citynmb.com/DocumentCenter/View/14691/2025-CCR-ENGLISH-web-version
https://www.citynmb.com/904/Source
https://www.miamidade.gov/global/water/conservation/outdoor-water-restrictions.page
Updated 2026-10-17 · Living Waters · Jorge Canela, Water Quality Specialist