What Cyanide is, and why it's regulated
What the EPA limit means
200 µg/L
Maximum Contaminant Level — the enforceable ceiling a supplier must stay under.
200 µg/L
Health goal (MCLG) — the level with no known health effect. It is a goal, not a legal limit, and is often zero for carcinogens.
SYR4
Where these measurements come from. Hover the tag for the EPA programme and years.
Where Cyanide was found
The water suppliers reporting the highest levels, worst first. For lead and copper that is the 90th-percentile result the action level is written against; for Six-Year Review data, the 95th percentile of each system's samples.
| Supplier | City | State | Level vs EPA limit |
|---|---|---|---|
| City of Santa Barbara Water Department | Santa Barbara | CA | 11870 µg/L 5935% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Twin Lakes | Twin Lakes | MN | 1294 µg/L 647% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Leisure Hills Mobile Home Park | — | AR | 1050 µg/L 525% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Provincetown Water Department | Provincetown | MA | 910 µg/L 455% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Middletown Water Utility | Middletown | IN | 900 µg/L 450% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Chesterfield Water Department | Chesterfield | IN | 800 µg/L 400% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Apple Valley | Apple Valley | MN | 769 µg/L 385% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Elpine Village | Bemidji | MN | 760 µg/L 380% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Glendale-City, Water Dept. | Glendale | CA | 640 µg/L 320% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Strandquist | Strandquist | MN | 590 µg/L 295% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| New Harmony Water Utility | New Harmony | IN | 573 µg/L 287% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Barton Lexa Water Association | Poplar Grove | AR | 497.5 µg/L 249% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Baldwin Lake Estates | — | MN | 472.5 µg/L 236% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Aaseby Court | Thief River Falls | MN | 470 µg/L 235% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Johnson Co Rwd 1 | Tecumseh | NE | 378 µg/L 189% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Jackson, Village of | Jackson | NE | 373.385 µg/L 187% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Ada | Ada | MN | 360 µg/L 180% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Stony Bar Estates | Pelican Rapids | MN | 326.5 µg/L 163% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Wilburn Water Association | Heber Springs | AR | 292 µg/L 146% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Town of Avon | Avon | MA | 280 µg/L 140% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Movil Lake Trailer Park | Bemidji | MN | 272.5 µg/L 136% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Decatur Waterworks | Decatur | AR | 270 µg/L 135% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Culver Water Department | Culver | IN | 250 µg/L 125% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| Dawson, Village of | Dawson | NE | 242 µg/L 121% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
| City of Gladewater | Gladewater | TX | 230.4 µg/L 115% of the EPA limit, at the 95th percentile of samples — 200 µg/L |
Frequently asked questions about Cyanide
What is Cyanide in drinking water?
Cyanide comes from steel, plastics and fertiliser discharge; high exposure affects the nerves and thyroid.
What is the EPA limit for Cyanide?
The EPA's Maximum Contaminant Level for Cyanide is 200 µg/L, and its health goal (MCLG) is 200 µg/L. A result above the limit means the supplier must act; the goal is the level at which no health effects are expected.
How common is Cyanide in US tap water?
Of the 25,878 water suppliers with results on file, 2,240 detected Cyanide — 8.7% of those tested.