Where the orange comes from
Iron dissolved in groundwater is invisible until it meets air. Once the water sprays out of a sprinkler head and dries on a stucco wall or a concrete walkway, the iron oxidizes and leaves the familiar orange band. In Miami this pattern usually lines up with the reach of the sprinkler heads, which is a strong hint that the irrigation water, not the house water, is the cause.
Miami-Dade's outdoor watering rules apply to every water source, including private wells and canals, which tells you how many properties in the county water their yards from something other than the utility. Odd-numbered addresses may water Wednesdays and Saturdays, even-numbered addresses Thursdays and Sundays, before 10 a.m. or after 4 p.m.
Stains inside the house
WASD treats Miami's Biscayne Aquifer water at its regional plants before it reaches your tap, so persistent rust stains in a bathroom usually point to something closer to home:
- Older galvanized or iron plumbing in some pre-war and mid-century Miami houses, which can shed rust, especially after the water has been sitting.
- A water heater whose tank is corroding.
- A private drinking well, where iron comes straight from the ground.
- Main breaks or repairs on the street, which can stir up sediment for a short time. If discolored water persists, call WASD.
Iron bacteria: the slimy version
The Florida Department of Health describes iron bacteria as nuisance organisms that combine iron and oxygen into rusty deposits and slime. Clues include red stains in sinks, a swampy or oily odor, and red, slimy growth in the toilet tank. They are not known to cause disease, but they can clog a well and the plumbing, and the DOH notes they can create conditions where other bacteria grow. Heavy growth in a well is usually a job for a licensed well contractor before any filter goes in.
How to test and what helps
| Where you see stains | What to test | Common options |
|---|---|---|
| Walls, pavers, pool deck near sprinklers | Water from the irrigation well | Iron treatment on the irrigation line, or adjusting heads so they do not hit hard surfaces |
| Sinks, tubs, toilets on a private well | Raw well water: iron, manganese, hardness, pH | A well water system configured from the test |
| Sinks and tubs on WASD water | Hot and cold water at the tap | Plumbing or water heater inspection first |
While you decide on treatment, re-aiming sprinkler heads so they stop hitting walls and walkways cuts down on new staining.
Book a free test in Miami
Jorge looks at where the stains are, tests the water that is causing them, and explains the results in plain words. If the fix is a plumber or a sprinkler adjustment, he says so. Call, text or WhatsApp (305) 793-5974.
https://www.miamidade.gov/global/water/conservation/outdoor-water-restrictions.page
https://www.floridahealth.gov/wp-content/uploads/2025/08/well-water-facts-odor-staining.pdf
https://www.miamidade.gov/water/library/reports/water-quality-2024.pdf
Updated 2026-10-17 · Living Waters · Jorge Canela, Water Quality Specialist