Inorganic chemicals
Ammonia in U.S. tap water
26 public water systems across 8 U.S. states report Ammonia in their annual Consumer Confidence Report. None currently sit at or above the federal limit.
Within the federal limit (1)
| Water system | Measured |
|---|---|
| Columbus, OH 2025 annual report | Not detected |
Ammonia by state
Every state where a public water system reports Ammonia in its annual report, ranked by systems at or above the federal limit.
Frequently asked
+What is Ammonia?
Ammonia is a contaminant some U.S. public water utilities measure and report in their annual Consumer Confidence Report.
+Does Ammonia have a federal limit in drinking water?
Ammonia does not have an enforceable federal MCL. Utilities still report any measured levels in their annual Consumer Confidence Report.
+How many U.S. water systems have Ammonia over the federal limit?
Zero of the 26 public water systems in The Water Map dataset currently report Ammonia at or above its federal limit.
+Which states report the most Ammonia in their drinking water?
No state currently has a system reporting Ammonia at or above its federal limit in The Water Map dataset. Wisconsin, California, Utah have the most systems measuring it.
+How can I check if Ammonia 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 Ammonia.