Metals
Iron in U.S. tap water
151 public water systems across 21 U.S. states report Iron in their annual Consumer Confidence Report. None currently sit at or above the federal limit.
What it is
A naturally occurring metal common in groundwater.
Why it's regulated
Regulated only as a secondary (cosmetic) standard; causes rusty color, staining, and metallic taste.
Within the federal limit (35)
| Water system | Measured |
|---|---|
| Kent, WA 2024 annual report | 0.028 mg/L |
| Allentown, PA 2024 annual report | Not detected mg/L |
| Ann Arbor, MI 2024 annual report | Not detected mg/L |
| Catoosa Utility District Authority, TN 2025 annual report | Not detected mg/L |
| Chattanooga, TN 2025 annual report | Not detected mg/L |
| Chowchilla City Water Dept — Chowchilla, Ca, CA 2021 annual report | Not detected ug/L |
| City of South Pasadena — South Pasadena, Ca, CA 2022 annual report | Not detected ug/L |
| Cleveland, OH 2024 annual report | Not detected mg/L |
| Colton, City of — Colton, Ca, CA 2023 annual report | Not detected ug/L |
| Columbus, OH 2025 annual report | Not detected mg/L |
| Covina Irrigating Co. — West Covina, Ca, CA 2021 annual report | Not detected ug/L |
| East Ridge, TN 2025 annual report | Not detected mg/L |
| El Monte, CA 2024 annual report | Not detected ug/L |
| Foothill Municipal Water Dist. — La Canada Flintridge, Ca, CA 2023 annual report | Not detected ug/L |
| Golden Hills Csd — Tehachapi, Ca, CA 2022 annual report | 0 ug/L |
| Gonzales, City of — Gonzales, Ca, CA 2022 annual report | Not detected ug/L |
| High Point, NC 2024 annual report | Not detected mg/L |
| La Canada Irrigation Dist. — La Canada, Ca, CA 2022 annual report | Not detected ug/L |
| La Canada Irrigation Dist. — La Canada, Ca, CA 2023 annual report | Not detected ug/L |
| La Canada Irrigation Dist. — La Canada, Ca, CA 2020 annual report | Not detected ug/L |
| Lookout Mountain, TN 2025 annual report | Not detected mg/L |
| Nashville, TN 2023 annual report | Not detected mg/L |
| Pomona, CA 2024 annual report | Not detected ug/L |
| Rainbow Municipal Wd — Fallbrook, Ca, CA 2023 annual report | Not detected mg/L |
| Red Bank, TN 2025 annual report | Not detected mg/L |
| Rossville, TN 2025 annual report | Not detected mg/L |
| Rubio Canon Land & Water Association — Altadena, Ca, CA 2020 annual report | Not detected ug/L |
| Running Springs Water District — Running Springs, Ca, CA 2023 annual report | Not detected ug/L |
| Santa Margarita Water District-id9 — Rancho Santa Margarita, Ca, CA 2023 annual report | Not detected ug/L |
| Signal Mountain, TN 2025 annual report | Not detected mg/L |
| Smwd - Sj Ground Water Plant — Rancho Santa Margarita, Ca, CA 2022 annual report | Not detected ug/L |
| Smwd - Sj Ground Water Plant — Rancho Santa Margarita, Ca, CA 2021 annual report | Not detected ug/L |
| Terrace Water Company — Colton, Ca, CA 2023 annual report | Not detected ug/L |
| Three Valleys MWD — Claremont, Ca, CA 2023 annual report | Not detected ug/L |
| Walker County, TN 2025 annual report | Not detected mg/L |
Frequently asked
+What is Iron?
A naturally occurring metal common in groundwater. Regulated only as a secondary (cosmetic) standard; causes rusty color, staining, and metallic taste.
+What is the federal limit for Iron in drinking water?
The federal Secondary MCL for Iron is 0.3 mg/L. The EPA enforces this against the regulated reporting statistic (typically a running annual average or 90th percentile), not a single-sample spike.
+How many U.S. water systems have Iron over the federal limit?
Zero of the 151 public water systems in The Water Map dataset currently report Iron at or above its federal limit.
+How can I check if Iron is in my city's tap water?
Search your city on The Water Map (https://www.thewatermap.com/) or browse the list on this page. Every U.S. public water utility is required to publish an annual Consumer Confidence Report that lists every contaminant it measured, including Iron.