Metals
Boron in U.S. tap water
284 public water systems across 5 U.S. states report Boron in their annual Consumer Confidence Report. None currently sit at or above the federal limit.
What it is
A naturally occurring element from rock and soil.
Why it's regulated
No enforceable federal limit; the EPA has issued a health advisory level.
Within the federal limit (5)
| Water system | Measured |
|---|---|
| Bleich Flats Mutual — Lancaster, Ca, CA 2020 annual report | Not detected |
| City of Yuba City — Yuba City, Ca, CA 2023 annual report | Not detected ug/L |
| Coastside County Water District — Half Moon Bay, Ca, CA 2023 annual report | Not detected ug/L |
| Crestline Village Cwd - Division 10 — Crestline, Ca, CA 2023 annual report | Not detected ug/L |
| Muscoy Mwc No. 1 — San Bernardino, Ca, CA 2023 annual report | Not detected ug/L |
Frequently asked
+What is Boron?
A naturally occurring element from rock and soil. No enforceable federal limit; the EPA has issued a health advisory level.
+What is the federal limit for Boron in drinking water?
The federal NL for Boron is 1000 ug/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 Boron over the federal limit?
Zero of the 284 public water systems in The Water Map dataset currently report Boron at or above its federal limit.
+How can I check if Boron 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 Boron.