Metals
Potassium in U.S. tap water
82 public water systems across 13 U.S. states report Potassium in their annual Consumer Confidence Report. 3 sit at or above the federal limit.
What it is
A naturally occurring mineral from rock and soil.
Why it's regulated
Not federally regulated for health.
At or above the federal limit (3)
| Water system | Measured | vs. limit |
|---|---|---|
| Pomona, CA 2024 annual report | 4.6–5 mg/L | 25.0× the limit |
| Burbank, CA 2024 annual report | 2.6–4.6 mg/L | 4.6× the limit |
| Vancouver, WA 2024 annual report | 4 mg/L | 1.0× the limit |
Within the federal limit (1)
| Water system | Measured |
|---|---|
| Overland Park, KS 2023 annual report | 7.4 |
Frequently asked
+What is Potassium?
A naturally occurring mineral from rock and soil. Not federally regulated for health.
+What is the federal limit for Potassium in drinking water?
The federal MCL for Potassium is 1 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 Potassium over the federal limit?
3 of the 82 public water systems on The Water Map report Potassium at or above its federal limit, spanning 13 U.S. states. The full list is on this page.
+How can I check if Potassium 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 Potassium.