Simazine
Status: National drinking water standard exists
Simazine is a hormone-disrupting herbicide related to atrazine. It affects the male and female reproductive systems. In studies of laboratory animals, simazine increases blood levels of estrogen, decreases prolactin and progesterone, and causes mammary and ovarian tumors.
2017-2019:
22
states detected
703
utilities detected
19 million
people served
9
states over health guideline
200
utilities over health guideline
2.7 million
people served over health guideline
0
states over legal limit
0
utilities over legal limit
0
people served over legal limit
Health concerns for simazine
Harm to the developing fetus
Hormone disruption
Harm to the reproductive system
Changes in the nervous system
Changes in brain and behavior
Cancer
State and national drinking water standards and health guidelines
EWG Health Guideline 0.1 ppb
The EWG Health Guideline of 0.1 ppb for simazine was defined by EWG based on epidemiological studies of human exposure to atrazine in drinking water. This health guideline protects against harm to the developing fetus, harm to the reproductive system and hormone disruption.
EPA Maximum Contaminant
Level (MCL) 4 ppb
The legal limit for simazine, established in 1992, was based on toxicity studies in laboratory animals conducted in the 1980s. This limit does not fully protect against harm to the reproductive system, harm to the developing fetus, and hormone disruption.
ppb = parts per billion
States reporting simazine in drinking water
| UTILITIES REPORTING ABOVE HEALTH GUIDELINES | UTILITIES WITH CONTAMINATION | ||||||
|---|---|---|---|---|---|---|---|
| State | Utilities | People Served | Utilities | People Served | |||
| Texas | 101 | 2,358,949 | 341 | 10,106,340 | |||
| Maryland | 0 | 0 | 10 | 2,117,546 | |||
| Ohio | 2 | 55,859 | 48 | 1,701,596 | |||
| Indiana | 2 | 14,902 | 26 | 1,346,682 | |||
| North Carolina | 14 | 75,744 | 56 | 1,127,156 | |||
| Louisiana | 0 | 0 | 7 | 974,633 | |||
| Virginia | 0 | 0 | 5 | 472,794 | |||
| Illinois | 76 | 198,318 | 122 | 319,017 | |||
| Florida | 0 | 0 | 13 | 298,293 | |||
| Kentucky | 0 | 0 | 17 | 155,328 | |||
| Oklahoma | 1 | 9,450 | 5 | 117,571 | |||
| Missouri | 1 | 2,529 | 4 | 77,491 | |||
| Rhode Island | 0 | 0 | 4 | 67,053 | |||
| Iowa | 2 | 7,502 | 30 | 66,686 | |||
| Massachusetts | 0 | 0 | 2 | 27,171 | |||
| Arkansas | 0 | 0 | 1 | 18,108 | |||
| Alabama | 0 | 0 | 3 | 15,225 | |||
| West Virginia | 0 | 0 | 1 | 6,797 | |||
| Nebraska | 0 | 0 | 1 | 5,555 | |||
| Connecticut | 0 | 0 | 1 | 4,020 | |||
| Arizona | 1 | 80 | 5 | 1,842 | |||
| Washington | 0 | 0 | 1 | 300 | |||
Filtering technologies that reduce simazine
Activated Carbon
Reverse Osmosis
Utilities with the highest amounts of simazine, 2017-2019
| Utility | Location | Tests | Average level | People served |
|---|---|---|---|---|
| Mount Olive | Mount Olive, IL | 11 of 24 | 0.552 ppb | 2,150 |
| Salem* | Salem, IL | 7 of 23 | 0.452 ppb | 9,000 |
| Hillsboro* | Hillsboro, IL | 11 of 25 | 0.427 ppb | 4,359 |
| Schram City | Hillsboro, IL | 11 of 25 | 0.427 ppb | 586 |
| Taylor Springs | Taylor Springs, IL | 11 of 25 | 0.427 ppb | 600 |
| Coffeen | Aviston, IL | 11 of 25 | 0.427 ppb | 685 |
| Greenfield | Greenfield, IL | 3 of 20 | 0.380 ppb | 1,200 |
| Carlinville* | Carlinville, IL | 8 of 25 | 0.374 ppb | 5,917 |
| Lake Williamson Christian Center | Carlinville, IL | 8 of 25 | 0.374 ppb | 1,250 |
| Westwego Waterworks | Westwego, LA | 2 of 4 | 0.355 ppb | 8,534 |
| Evansville | Evansville, IL | 6 of 23 | 0.341 ppb | 700 |
| Vernon | Vernon, IL | 8 of 24 | 0.325 ppb | 129 |
| Xenia | Xenia, IL | 8 of 24 | 0.325 ppb | 545 |
| Farina | Farina, IL | 8 of 24 | 0.325 ppb | 600 |
| Fmc Water Company* | Odin, IL | 8 of 24 | 0.325 ppb | 3,129 |
| Patoka | Patoka, IL | 8 of 24 | 0.325 ppb | 603 |
| Gateway Regional Water Company* | Sandoval, IL | 8 of 24 | 0.325 ppb | 1 |
| Flora* | Flora, IL | 8 of 24 | 0.325 ppb | 5,478 |
| Sparta* | Sparta, IL | 9 of 24 | 0.292 ppb | 4,600 |
| Coulterville | Coulterville, IL | 2 of 14 | 0.276 ppb | 985 |
| Jericho Water District | Syosset, NY | 30 of 97 | 0.260 ppb | 58,000 |
| Summerfield | Summerfield, IL | 8 of 26 | 0.247 ppb | 471 |
| S L M Water Commission* | Mascoutah, IL | 8 of 26 | 0.247 ppb | 300 |
| Fsh Water Commission* | Freeburg, IL | 8 of 26 | 0.247 ppb | 310 |
| Fayetteville | Swansea, IL | 8 of 26 | 0.247 ppb | 441 |
| New Baden* | New Baden, IL | 8 of 26 | 0.247 ppb | 3,349 |
| Lebanon | Lebanon, IL | 8 of 26 | 0.247 ppb | 4,418 |
| New Memphis Public Water District | New Memphis, IL | 8 of 26 | 0.247 ppb | 900 |
| Trenton | Trenton, IL | 8 of 26 | 0.247 ppb | 3,180 |
| Mascoutah | Mascoutah, IL | 8 of 26 | 0.247 ppb | 9,002 |
| Tritownship Water District* | Trenton, IL | 8 of 26 | 0.247 ppb | 4,025 |
| City of Grapevine | Grapevine, TX | 7 of 9 | 0.239 ppb | 47,851 |
| W G Murray Development Center | Cenralia, IL | 8 of 24 | 0.235 ppb | 290 |
| Centralia* | Centralia, IL | 8 of 24 | 0.235 ppb | 14,274 |
| Wamac | Centralia, IL | 8 of 24 | 0.235 ppb | 1,501 |
| Junction City | Centralia, IL | 8 of 24 | 0.235 ppb | 514 |
| Irvington* | Centralia, IL | 8 of 24 | 0.235 ppb | 1,245 |
| Walnut Hill* | Centralia, IL | 8 of 24 | 0.235 ppb | 1,305 |
| Sandoval | Sandoval, IL | 8 of 24 | 0.235 ppb | 1,528 |
| Hoyleton Rwc | Centralia, IL | 8 of 24 | 0.235 ppb | 1,147 |
| Kinmundy | Kinmundy, IL | 2 of 8 | 0.235 ppb | 940 |
| Apple Creek Water Co-op | Waverly, IL | 3 of 14 | 0.229 ppb | 949 |
| Waverly* | Waverly, IL | 3 of 14 | 0.229 ppb | 1,307 |
| Fort Bend County MUD 134e | Houston, TX | 5 of 32 | 0.218 ppb | 219 |
| Fort Bend County Municipal Utility District 134d | Houston, TX | 5 of 32 | 0.218 ppb | 105 |
| Pecan Grove MUD* | Houston, TX | 5 of 32 | 0.218 ppb | 14,913 |
| Humboldt | Humboldt, IL | 6 of 24 | 0.201 ppb | 437 |
| Mattoon* | Mattoon, IL | 6 of 24 | 0.201 ppb | 19,000 |
| Osceola Water Works* | Osceola, IA | 2 of 4 | 0.200 ppb | 4,929 |
| Sirwa #3 (osceola) | Creston, IA | 2 of 4 | 0.200 ppb | 2,573 |
* 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 Simazine, but it likely has the contaminant in its water supply.
| Utility | Location | Tests | Average level | People served |
|---|---|---|---|---|
| Jericho Water District | Syosset, NY | 30 of 97 | 0.260 ppb | 58,000 |
| City of Grapevine | Grapevine, TX | 7 of 9 | 0.239 ppb | 47,851 |
| Centralia* | Centralia, IL | 8 of 24 | 0.235 ppb | 14,274 |
| Pecan Grove MUD* | Houston, TX | 5 of 32 | 0.218 ppb | 14,913 |
| Mattoon* | Mattoon, IL | 6 of 24 | 0.201 ppb | 19,000 |
| Town of Smithfield* | Smithfield, NC | 7 of 19 | 0.186 ppb | 12,400 |
| E J Water Corp* | Dieterich, IL | 5 of 20 | 0.156 ppb | 23,669 |
| Town of Tarboro* | Tarboro, NC | 5 of 18 | 0.141 ppb | 11,310 |
| Springfield* | Springfield, IL | 3 of 19 | 0.136 ppb | 119,395 |
| University Park | Dallas, TX | 5 of 6 | 0.133 ppb | 23,040 |
| Pennsylvania American Coatesville* | Coatesville, PA | 2 of 10 | 0.127 ppb | 30,299 |
| City of Lewisville* | Lewisville, TX | 7 of 12 | 0.123 ppb | 104,780 |
| Murphysboro* | Murphysboro, IL | 19 of 26 | 0.123 ppb | 10,941 |
| City of Livingston | Livingston, TX | 5 of 6 | 0.117 ppb | 11,692 |
| Harris County FWSD 51* | Houston, TX | 10 of 12 | 0.101 ppb | 10,401 |
| West Jefferson Waterworks District 2* | Jefferson, LA | 5 of 25 | 0.100 ppb | 188,770 |
| City of Texas City | Texas City, TX | 8 of 18 | 0.0989 ppb | 48,558 |
| Greensburg Municipal Water Works* | Greensburg, IN | 6 of 24 | 0.0967 ppb | 12,000 |
| Walpole Water Department | Walpole, MA | 13 of 20 | 0.0945 ppb | 23,989 |
| City of South Houston | South Houston, TX | 20 of 33 | 0.0942 ppb | 17,397 |
| City of Midlothian* | Midlothian, TX | 7 of 17 | 0.0924 ppb | 16,728 |
| City of Sugar Land* | Sugar Land, TX | 12 of 34 | 0.0924 ppb | 83,886 |
| Harris County WCID 36 | Houston, TX | 6 of 12 | 0.0883 ppb | 11,065 |
| Piqua City PWS | Piqua, OH | 9 of 36 | 0.0871 ppb | 20,522 |
| Effingham* | Effingham, IL | 2 of 17 | 0.0829 ppb | 12,328 |
| Johnston County - West* | Smithfield, NC | 9 of 19 | 0.0826 ppb | 58,354 |
| Clayton | Clayton, NC | 9 of 19 | 0.0826 ppb | 19,822 |
| City of Monroe | Monroe, NC | 7 of 24 | 0.0818 ppb | 31,438 |
| City of La Marque | La Marque, TX | 2 of 6 | 0.0817 ppb | 15,154 |
| City of Galveston* | Galveston, TX | 2 of 6 | 0.0817 ppb | 50,180 |
| Del-Co Water Company Inc.* | Delaware, OH | 32 of 43 | 0.0810 ppb | 141,407 |
| Johnston County - East* | Smithfield, NC | 10 of 18 | 0.0800 ppb | 31,250 |
| Lafourche Water District 1 | Lockport, LA | 4 of 46 | 0.0783 ppb | 78,760 |
| East Fork SUD | Wylie, TX | 7 of 17 | 0.0753 ppb | 13,596 |
| Town of Prosper | Prosper, TX | 7 of 17 | 0.0753 ppb | 22,650 |
| City of Forney* | Forney, TX | 7 of 17 | 0.0753 ppb | 19,122 |
| City of Princeton* | Princeton, TX | 7 of 17 | 0.0753 ppb | 16,932 |
| Caddo Basin SUD | Greenville, TX | 7 of 17 | 0.0753 ppb | 13,335 |
| City of Allen | Allen, TX | 7 of 17 | 0.0753 ppb | 102,762 |
| City of Rowlett | Rowlett, TX | 7 of 17 | 0.0753 ppb | 59,300 |
| Town of Little Elm* | Little Elm, TX | 7 of 17 | 0.0753 ppb | 41,796 |
| City of Plano* | Plano, TX | 7 of 17 | 0.0753 ppb | 277,720 |
| City of Garland | Garland, TX | 7 of 17 | 0.0753 ppb | 236,786 |
| City of Sachse | Sachse, TX | 7 of 17 | 0.0753 ppb | 25,937 |
| City of Frisco* | Frisco, TX | 7 of 17 | 0.0753 ppb | 192,261 |
| City of Mesquite* | Mesquite, TX | 7 of 17 | 0.0753 ppb | 143,350 |
| City of Richardson | Richardson, TX | 7 of 17 | 0.0753 ppb | 104,300 |
| City of Wylie | Wylie, TX | 7 of 17 | 0.0753 ppb | 44,418 |
| City of McKinney* | Mckinney, TX | 7 of 17 | 0.0753 ppb | 169,710 |
| City of Murphy | Murphy, TX | 7 of 17 | 0.0753 ppb | 20,361 |
* 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 Simazine, but it likely has the contaminant in its water supply.