Menu

EWG's Tap Water Database — 2021 UPDATE

Donate

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.

2017-2019:

FOUND
FOUND ABOVE HEALTH GUIDELINES

39

states detected

1,824

utilities detected

27 million

people served

0

states over health guideline

0

utilities over health guideline

0

people served over health guideline

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 UtilitiesPeople Served
Texas1,04017,028,625
Florida1082,539,181
New York911,733,886
Utah50933,689
California24801,551
Missouri32783,278
Pennsylvania62651,038
New Jersey38415,877
North Carolina15396,608
Alabama9363,642
Mississippi38319,878
Kentucky39286,065
Louisiana25276,885
West Virginia56229,779
Oklahoma2106,928
Wisconsin698,493
Ohio1984,615
Iowa2880,799
Indiana1451,810
New Mexico951,491
Delaware1146,180
Arkansas1230,133
Illinois1125,243
Tennessee325,139
Nebraska1818,606
Virginia814,436
Minnesota2814,312
Vermont211,495
Michigan19,390
Hawaii15,998
Massachusetts22,864
Rhode Island22,626
Arizona31,726
Washington5752
Connecticut4580
Oregon3484
Alaska1461
Maine382
Georgia152
MORE
LESS

Filtering technologies that reduce cyanide

Reverse Osmosis

Ion Exchange

Utilities with the highest amounts of cyanide, 2017-2019

ALL UTILITIES
LARGE UTILITIES
UtilityLocationTestsAverage levelPeople served
Middletown Water UtilityMiddletown, IN1 of 2450.0 ppb2,050
Chesterfield Water DepartmentChesterfield, IN1 of 3266.7 ppb2,800
Rambo WaterRogers, AR14 of 19260.5 ppb93
Elpine VillageBemidji, MN1 of 3253.3 ppb125
Aaseby CourtThief River Falls, MN5 of 10217.0 ppb50
New Harmony Water UtilityNew Harmony, IN1 of 3191.0 ppb1,633
Crab Orchard, Village of*Crab Orchard, NE1 of 2189.0 ppb56
Johnson County Rural Water District #1 West*Tecumseh, NE1 of 2189.0 ppb962
StrandquistStrandquist, MN6 of 10186.2 ppb77
Armstrong Water Supply CorporationHolland, TX1 of 1180.0 ppb2,838
City of Odessa*Odessa, TX3 of 3173.0 ppb97,802
Ector County Utility DistrictOdessa, TX3 of 3173.0 ppb15,300
City of OdonnellOdonnell, TX2 of 2172.0 ppb831
Township 29 Water AssociationMount Vernon, WA1 of 1172.0 ppb38
Harris County Municipal Utility District 383*Houston, TX2 of 2160.0 ppb4,062
City of Anson*Anson, TX2 of 2154.0 ppb2,500
Harris County Municipal Utility District 183Houston, TX2 of 2150.0 ppb3,999
City of Corpus Christi*Corpus Christi, TX27 of 28148.2 ppb325,733
Corpus Christi Naval Air StationCorpus Christi, TX27 of 28148.2 ppb8,349
Violet Water Supply CorporationRobstown, TX27 of 28148.2 ppb2,670
South Texas Water Authority*Kingsville, TX27 of 28148.2 ppb0
Verdel, Village ofNiobrara, NE1 of 1146.0 ppb30
Lakeshore Sites WaterHaskell, TX2 of 2144.5 ppb58
Paint Creek Water Supply Corporation*Stamford, TX2 of 2144.5 ppb445
Leisure HillsWestfork, AR9 of 15140.0 ppb105
City of EarlyBrownwood, TX1 of 1140.0 ppb2,980
Valley Municipal Utility District 2 Rancho ViejoBrownsville, TX6 of 6136.7 ppb2,500
Harris County Municipal Utility District 400 - West*Houston, TX2 of 2135.0 ppb4,029
FreebornFreeborn, MN1 of 3130.0 ppb297
City of La FeriaLa Feria, TX6 of 6128.3 ppb8,247
City of Baird*Baird, TX7 of 8126.4 ppb1,492
Harris County Municipal Utility District 155*Houston, TX2 of 2125.0 ppb2,433
Harris County Municipal Utility District 162Houston, TX2 of 2125.0 ppb2,649
Culver Water DepartmentCulver, IN1 of 2125.0 ppb1,391
Southmost Regional Water Authority*Brownsville, TX2 of 2125.0 ppb0
Harris County Municipal Utility District 156Houston, TX2 of 2125.0 ppb2,115
West Harris County Municipal Utility District 15*Houston, TX4 of 4125.0 ppb672
City of Clyde*Clyde, TX18 of 18120.8 ppb3,345
West Bell County Water Supply CorporationKilleen, TX12 of 12119.2 ppb4,308
City of RogersRogers, TX12 of 12119.2 ppb1,455
City of LottLott, TX12 of 12119.2 ppb1,056
City of BuckholtsBuckholts, TX12 of 12119.2 ppb515
Central Texas Water Supply Corporation*Harker Heights, TX12 of 12119.2 ppb0
City of RosebudRosebud, TX12 of 12119.2 ppb2,226
City of HollandHolland, TX12 of 12119.2 ppb1,120
Dog Ridge Water Supply CorporationBelton, TX12 of 12119.2 ppb4,830
Mooreville Water Supply CorporationChilton, TX12 of 12119.2 ppb201
City of LawnLawn, TX23 of 24119.0 ppb780
Decatur WaterworksDecatur, AR17 of 25117.6 ppb2,383
Brownsville Public Utilities Board*Brownsville, TX12 of 12116.7 ppb176,362

* 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.

UtilityLocationTestsAverage levelPeople served
City of Odessa*Odessa, TX3 of 3173.0 ppb97,802
Ector County Utility DistrictOdessa, TX3 of 3173.0 ppb15,300
City of Corpus Christi*Corpus Christi, TX27 of 28148.2 ppb325,733
Brownsville Public Utilities Board*Brownsville, TX12 of 12116.7 ppb176,362
City of Waco*Waco, TX22 of 27115.2 ppb130,194
City of HuttoHutto, TX2 of 2110.0 ppb16,638
City of Nederland*Nederland, TX5 of 6110.0 ppb17,545
City of LeanderLeander, TX6 of 6110.0 ppb43,764
City of Abilene*Abilene, TX29 of 29109.3 ppb123,886
Langham Creek Utility District*Houston, TX5 of 6106.7 ppb10,377
City of Sweetwater*Sweetwater, TX6 of 6101.6 ppb11,760
Lubbock Public Water System*Lubbock, TX9 of 10101.4 ppb266,263
City of BeltonBelton, TX17 of 1797.6 ppb21,214
City of KilleenKilleen, TX17 of 1797.6 ppb140,806
City of Copperas Cove*Copperas Cove, TX17 of 1797.6 ppb33,919
US Army South Fort HoodFort Hood, TX17 of 1797.6 ppb35,669
City of Harker HeightsHarker Heights, TX17 of 1797.6 ppb30,365
City of Mesquite*Mesquite, TX16 of 1893.6 ppb143,350
City of Rockwall*Rockwall, TX16 of 1893.6 ppb43,750
City of AllenAllen, TX16 of 1893.6 ppb102,762
City of Forney*Forney, TX16 of 1893.6 ppb19,122
City of Terrell*Terrell, TX16 of 1893.6 ppb17,500
Town of Little Elm*Little Elm, TX16 of 1893.6 ppb41,796
City of RowlettRowlett, TX16 of 1893.6 ppb59,300
City of GarlandGarland, TX16 of 1893.6 ppb236,786
City of FateFate, TX16 of 1893.6 ppb14,327
City of WylieWylie, TX16 of 1893.6 ppb44,418
Town of ProsperProsper, TX16 of 1893.6 ppb22,650
East Fork SUDWylie, TX16 of 1893.6 ppb13,596
City of Frisco*Frisco, TX16 of 1893.6 ppb192,261
City of McKinney*Mckinney, TX16 of 1893.6 ppb169,710
City of Plano*Plano, TX16 of 1893.6 ppb277,720
Caddo Basin SUDGreenville, TX16 of 1893.6 ppb13,335
City of RichardsonRichardson, TX16 of 1893.6 ppb104,300
City of SachseSachse, TX16 of 1893.6 ppb25,937
City of Royse CityRoyse City, TX16 of 1893.6 ppb14,212
City of MurphyMurphy, TX16 of 1893.6 ppb20,361
City of Princeton*Princeton, TX16 of 1893.6 ppb16,932
City of Snyder*Snyder, TX2 of 292.1 ppb10,783
City of Georgetown*Georgetown, TX48 of 5592.0 ppb102,687
City of Brenham*Brenham, TX5 of 690.0 ppb15,716
City of EdinburgEdinburg, TX11 of 1286.7 ppb85,224
Ashland Water and Sewer Department*Ashland, MA1 of 286.0 ppb16,593
Wells Branch MUD 1Austin, TX16 of 1785.9 ppb22,062
North Austin Municipal Utility District 1Austin, TX16 of 1785.9 ppb11,133
City of Austin Water & Wastewater*Austin, TX16 of 1785.9 ppb981,783
Northtown MUDAustin, TX16 of 1785.9 ppb11,520
City of Mansfield*Mansfield, TX5 of 685.4 ppb68,612
Franklin Water DepartmentFranklin, TN1 of 185.0 ppb52,781
North Alamo Water Supply Company*Edinburg, TX44 of 4983.3 ppb138,855

* 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.