Common sources on the island
- Private irrigation source: if your sprinklers draw from a well rather than WASD water, iron in that water can stain anything it hits.
- Rusting metal in salt air: railings, pool equipment, screws and fixtures can bleed rust when rinsed or rained on.
- Older pipes: galvanized or corroding pipes in older homes and buildings can release rust into hot or cold water.
- Main work or flushing: disturbing a water main can temporarily stir up sediment; running cold water usually clears it.
Narrow it down
| Where you see it | Check first |
|---|---|
| Stripes where sprinklers hit | Irrigation water source |
| Below railings or fixtures | Rusting metal |
| Toilet tanks and sinks | House or building pipes |
| Laundry, after a main break nearby | Temporary sediment |
Condos and towers
Rust-colored water at a single unit often comes from the building's risers or your unit's pipes and water heater. Report it to building management and note whether it is hot, cold or both. An under-sink system will not fix pipe corrosion, but it does treat drinking water at the tap.
Testing
Jorge can test iron in the water at your faucet or the irrigation outlet, plus chlorine to confirm whether it is WASD water. If a private well is involved, the Florida Department of Health has guidance on testing private wells. Call, text or WhatsApp (305) 793-5974.
Pools and pool decks
Island pools see stains more than most. Orange or brown marks on plaster or pavers can come from metal in pool equipment, metal objects left in the water, or fill water from a source with iron. Pool chemistry can also make metals drop out of solution.
- If the pool fills from WASD water through your meter, iron in the fill water is unlikely to be the cause.
- If it fills from a private source, test that water for iron before refilling.
- Ask your pool professional to check for corroding heaters, ladders, fittings and lights.
Jorge can test the water you fill with and help you rule sources in or out. Pool chemistry itself is a job for your pool service. Keeping notes on when stains appear, such as after a refill, heavy rain or new equipment, narrows the search quickly.
Options once you know
- Irrigation well with iron: treatment configured from that water's test, or adjusting sprinkler heads away from surfaces.
- Rusting metal: replace with stainless or coated hardware.
- Pipe corrosion: a plumber's inspection.
https://files.keybiscayne.fl.gov/Documents/Services/Building%20Zoning%20and%20Planning/Resources/Studies%20and%20Reports/VKB_MasterPlan_1995_Amended12-9-08.pdf
https://www.keybiscayne.fl.gov/services/public_works/utility.php
https://www.floridahealth.gov/community-environmental-public-health/environmental-public-health/water-quality/drinking-water/private-wells/
Updated 2026-10-17 · Living Waters · Jorge Canela, Water Quality Specialist