Physical & aggregate
Total Dissolved Solids in U.S. tap water
305 public water systems across 21 U.S. states report Total Dissolved Solids in their annual Consumer Confidence Report. None currently sit at or above the federal limit.
What it is
Total dissolved solids — the combined content of all dissolved minerals and salts.
Why it's regulated
Regulated only as a secondary (cosmetic) standard; high levels affect taste and hardness.
Within the federal limit (1)
| Water system | Measured |
|---|---|
| Kent, WA 2024 annual report | 25.2 mg/L |
Frequently asked
+What is Total Dissolved Solids?
Total dissolved solids — the combined content of all dissolved minerals and salts. Regulated only as a secondary (cosmetic) standard; high levels affect taste and hardness.
+What is the federal limit for Total Dissolved Solids in drinking water?
The federal Secondary MCL for Total Dissolved Solids is 500 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 Total Dissolved Solids over the federal limit?
Zero of the 305 public water systems in The Water Map dataset currently report Total Dissolved Solids at or above its federal limit.
+How can I check if Total Dissolved Solids 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 Total Dissolved Solids.