Physical & aggregate
Alkalinity in U.S. tap water
96 public water systems across 21 U.S. states report Alkalinity in their annual Consumer Confidence Report. 4 sit at or above the federal limit.
What it is
A measure of the water's capacity to neutralize acids.
Why it's regulated
Not federally regulated for health; relevant to corrosion control and treatment.
At or above the federal limit (4)
| Water system | Measured | vs. limit |
|---|---|---|
| Pomona, CA 2024 annual report | 140–170 mg/L | 170.0× the limit |
| Burbank, CA 2024 annual report | 98–230 mg/L | 115.0× the limit |
| San Diego, CA 2023 annual report | 123 mg/L | 24.6× the limit |
| Vancouver, WA 2024 annual report | 110 mg/L | 1.0× the limit |
Within the federal limit (1)
| Water system | Measured |
|---|---|
| Overland Park, KS 2023 annual report | 66 |
Frequently asked
+What is Alkalinity?
A measure of the water's capacity to neutralize acids. Not federally regulated for health; relevant to corrosion control and treatment.
+What is the federal limit for Alkalinity in drinking water?
The federal MCL for Alkalinity is 2 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 Alkalinity over the federal limit?
4 of the 96 public water systems on The Water Map report Alkalinity at or above its federal limit, spanning 21 U.S. states. The full list is on this page.
+How can I check if Alkalinity 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 Alkalinity.