Cyanide
Status: National drinking water standard exists
Cyanide is a toxic chemical that causes central nervous system and thyroid toxicity. Water contamination is generally the result of metal mining and chemical industry waste, runoff from agriculture and road salts used for melting ice.
2015-2017:
37
states detected
1,912
utilities detected
33 million
people served
0
states over health guideline
0
utilities over health guideline
0
people served over health guideline
0
states over legal limit
0
utilities over legal limit
0
people served over legal limit
Health concerns for cyanide
Harm to the brain and nervous system
Harm to the thyroid
Harm to the central nervous system
State and national drinking water standards and health guidelines
EWG Health Guideline 150 ppb
The EWG Health Guideline of 150 ppb for cyanide was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against harm to the brain and nervous system.
EPA Maximum Contaminant
Level (MCL) 200 ppb
The legal limit for cyanide, established in 1992, was based on a 1955 toxicity study conducted in laboratory animals. This limit does not include any additional consideration of children’s health.
ppb = parts per billion
States reporting cyanide in drinking water
| UTILITIES WITH CONTAMINATION | |||
|---|---|---|---|
| State | Utilities | People Served | |
| Texas | 1,118 | 17,308,961 | |
| Florida | 93 | 3,567,607 | |
| New Jersey | 50 | 2,606,889 | |
| Utah | 157 | 1,957,546 | |
| Louisiana | 22 | 1,447,433 | |
| New York | 95 | 1,446,708 | |
| Oklahoma | 6 | 815,162 | |
| Missouri | 31 | 789,805 | |
| District Of Columbia | 3 | 648,882 | |
| Kentucky | 61 | 589,657 | |
| Wisconsin | 11 | 397,954 | |
| California | 17 | 364,682 | |
| Mississippi | 44 | 345,644 | |
| Virginia | 6 | 216,042 | |
| Connecticut | 19 | 177,729 | |
| West Virginia | 28 | 113,589 | |
| North Carolina | 14 | 106,975 | |
| Massachusetts | 6 | 103,417 | |
| Ohio | 11 | 83,969 | |
| Tennessee | 8 | 82,328 | |
| North Dakota | 3 | 80,555 | |
| Indiana | 27 | 59,297 | |
| New Mexico | 5 | 44,155 | |
| Minnesota | 25 | 30,160 | |
| Arkansas | 14 | 29,203 | |
| Alabama | 3 | 27,576 | |
| Rhode Island | 3 | 12,700 | |
| Washington | 8 | 11,215 | |
| Colorado | 2 | 4,562 | |
| Nebraska | 7 | 3,747 | |
| Illinois | 4 | 1,855 | |
| Vermont | 1 | 1,695 | |
| Alaska | 3 | 1,311 | |
| Arizona | 2 | 1,299 | |
| Wyoming | 2 | 980 | |
| Georgia | 1 | 85 | |
| Oregon | 1 | 35 | |
| Maine | 1 | 25 | |
Filtering technologies that reduce cyanide
Reverse Osmosis
Ion Exchange
Utilities with the highest amounts of cyanide, 2015-2017
* This water utility supplies finished drinking water to at least one other water utility. The purchasing utility is not required to test for or report Cyanide, but it likely has the contaminant in its water supply.
| Utility | Location | Tests | Average level | People served |
|---|---|---|---|---|
| Ashland Water and Sewer Department* | Ashland, MA | 1 of 1 | 172.0 ppb | 16,593 |
| City of Corpus Christi* | Corpus Christi, TX | 12 of 13 | 153.1 ppb | 325,733 |
| City of Big Spring* | Big Spring, TX | 1 of 1 | 145.0 ppb | 27,282 |
| City of Hutto | Hutto, TX | 1 of 1 | 140.0 ppb | 16,638 |
| City of Sweetwater* | Sweetwater, TX | 3 of 3 | 133.0 ppb | 11,760 |
| Harris County FWSD 51* | Houston, TX | 2 of 2 | 130.0 ppb | 10,401 |
| City of Abilene* | Abilene, TX | 15 of 15 | 129.8 ppb | 123,886 |
| City of Waco* | Waco, TX | 15 of 17 | 122.4 ppb | 130,194 |
| City of Odessa* | Odessa, TX | 1 of 1 | 122.0 ppb | 97,802 |
| Ector County Utility District | Odessa, TX | 1 of 1 | 122.0 ppb | 15,300 |
| Harris County MUD 53 | Houston, TX | 2 of 2 | 120.0 ppb | 16,164 |
| Brownsville Public Utilities Board* | Brownsville, TX | 6 of 6 | 120.0 ppb | 176,362 |
| Langham Creek Utility District* | Houston, TX | 2 of 3 | 116.7 ppb | 10,377 |
| City of Murphy | Murphy, TX | 7 of 8 | 111.9 ppb | 19,850 |
| City of Rowlett | Rowlett, TX | 7 of 8 | 111.9 ppb | 58,407 |
| Town of Little Elm* | Little Elm, TX | 7 of 8 | 111.9 ppb | 31,355 |
| City of Fate | Fate, TX | 7 of 8 | 111.9 ppb | 14,327 |
| City of Richardson | Richardson, TX | 7 of 8 | 111.9 ppb | 104,300 |
| City of Frisco* | Frisco, TX | 7 of 8 | 111.9 ppb | 159,000 |
| City of Allen | Allen, TX | 7 of 8 | 111.9 ppb | 93,528 |
| Town of Prosper | Prosper, TX | 7 of 8 | 111.9 ppb | 22,650 |
| City of Royse City | Royse City, TX | 7 of 8 | 111.9 ppb | 11,988 |
| City of McKinney* | Mckinney, TX | 7 of 8 | 111.9 ppb | 169,710 |
| City of Rockwall* | Rockwall, TX | 7 of 8 | 111.9 ppb | 40,620 |
| East Fork SUD | Wylie, TX | 7 of 8 | 111.9 ppb | 13,596 |
| City of Mesquite* | Mesquite, TX | 7 of 8 | 111.9 ppb | 143,484 |
| City of Plano* | Plano, TX | 7 of 8 | 111.9 ppb | 277,720 |
| City of Garland | Garland, TX | 7 of 8 | 111.9 ppb | 236,786 |
| City of Forney* | Forney, TX | 7 of 8 | 111.9 ppb | 19,122 |
| City of Wylie | Wylie, TX | 7 of 8 | 111.9 ppb | 41,043 |
| City of Terrell* | Terrell, TX | 7 of 8 | 111.9 ppb | 24,744 |
| City of Sachse | Sachse, TX | 7 of 8 | 111.9 ppb | 23,681 |
| City of Leander | Leander, TX | 3 of 3 | 110.0 ppb | 43,764 |
| City of Belton | Belton, TX | 9 of 9 | 101.1 ppb | 21,214 |
| City of Killeen | Killeen, TX | 9 of 9 | 101.1 ppb | 140,806 |
| City of Copperas Cove* | Copperas Cove, TX | 9 of 9 | 101.1 ppb | 33,919 |
| City of Harker Heights | Harker Heights, TX | 9 of 9 | 101.1 ppb | 30,365 |
| US Army South Fort Hood | Fort Hood, TX | 9 of 9 | 101.1 ppb | 35,669 |
| Harris County MUD 200 Cranbrook* | Houston, TX | 3 of 3 | 100.0 ppb | 14,697 |
| City of Snyder* | Snyder, TX | 1 of 1 | 100.0 ppb | 10,783 |
| City of Nederland* | Nederland, TX | 2 of 3 | 96.7 ppb | 17,545 |
| East Rio Hondo WSC* | Rio Hondo, TX | 3 of 3 | 93.3 ppb | 21,726 |
| City of Brownwood | Brownwood, TX | 9 of 12 | 92.5 ppb | 18,965 |
| Brookesmith Special Utility District* | Brownwood, TX | 9 of 12 | 92.5 ppb | 11,289 |
| City of Georgetown* | Georgetown, TX | 25 of 27 | 92.2 ppb | 98,776 |
| Lubbock Public Water System* | Lubbock, TX | 4 of 5 | 91.6 ppb | 235,398 |
| City of San Juan | San Juan, TX | 5 of 6 | 90.0 ppb | 30,000 |
| City of Gatesville* | Gatesville, TX | 2 of 3 | 86.7 ppb | 14,430 |
| City of Midland | Midland, TX | 1 of 2 | 82.5 ppb | 132,950 |
| City of Austin Water & Wastewater* | Austin, TX | 8 of 9 | 82.2 ppb | 981,783 |
* This water utility supplies finished drinking water to at least one other water utility. The purchasing utility is not required to test for or report Cyanide, but it likely has the contaminant in its water supply.