Other
Hexachlorocyclopentadiene in U.S. tap water
27 public water systems across 8 U.S. states report Hexachlorocyclopentadiene in their annual Consumer Confidence Report. 2 sit at or above the federal limit.
At or above the federal limit (2)
| Water system | Measured | vs. limit |
|---|---|---|
| Mobile, AL 2024 annual report | 0.11 mg/L | 2.2× the limit |
| Montgomery, AL 2024 annual report | 0.1 mg/L | 2.0× the limit |
Within the federal limit (25)
Frequently asked
+What is Hexachlorocyclopentadiene?
Hexachlorocyclopentadiene is a contaminant some U.S. public water utilities measure and report in their annual Consumer Confidence Report.
+What is the federal limit for Hexachlorocyclopentadiene in drinking water?
The federal MCLG for Hexachlorocyclopentadiene is 0 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 Hexachlorocyclopentadiene over the federal limit?
2 of the 27 public water systems on The Water Map report Hexachlorocyclopentadiene at or above its federal limit, spanning 8 U.S. states. The full list is on this page.
+How can I check if Hexachlorocyclopentadiene 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 Hexachlorocyclopentadiene.
See Hexachlorocyclopentadiene on the map
Color-coded by status across the whole country.
Open the map →