Selenium
Status: National drinking water standard exists
Selenium is an essential element in diets. But too much selenium can decrease thyroid hormone production and cause hair loss, skin lesions and brittle fingernails.
2015:
45
states detected
3,209
utilities detected
33 million
people served
9
states over health guideline
37
utilities over health guideline
17,283
people served over health guideline
5
states over legal limit
7
utilities over legal limit
8,037
people served over legal limit
Health concerns for selenium
Hormone disruption
Harm to child development
Harm to the brain and nervous system
Skin damage
State and national drinking water standards and health guidelines
Health Guideline 30 ppb
The health guideline of 30 ppb for selenium 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 hair loss and nail damage.
ppb = parts per billion.
EPA Maximum Contaminant
Level (MCL) 50 ppb
The enforceable federal standard that defines the highest level of a contaminant allowed in drinking water.
ppb = parts per billion.
EPA Maximum Contaminant
Level Goal (MCLG)50.0 ppb
A non-enforceable federal health guideline. For cancer-causing chemicals, these health goals are typically set to zero.
ppb = parts per billion.
States reporting selenium in drinking water
| UTILITIES REPORTING ABOVE HEALTH GUIDELINES | UTILITIES WITH CONTAMINATION | ||||||
|---|---|---|---|---|---|---|---|
| State | Utilities | People Served | Utilities | People Served | |||
| Texas | 12 | 11,315 | 1,037 | 12,902,715 | |||
| California | 5 | 1,284 | 184 | 3,768,945 | |||
| Florida | 0 | 0 | 404 | 2,718,751 | |||
| Utah | 0 | 0 | 104 | 1,900,622 | |||
| Kansas | 9 | 2,191 | 374 | 1,881,473 | |||
| New Jersey | 0 | 0 | 200 | 1,822,183 | |||
| Arizona | 0 | 0 | 40 | 1,369,105 | |||
| Pennsylvania | 3 | 240 | 94 | 1,191,220 | |||
| Missouri | 0 | 0 | 51 | 913,146 | |||
| Colorado | 2 | 1,280 | 111 | 826,090 | |||
| Louisiana | 0 | 0 | 40 | 678,969 | |||
| Nevada | 1 | 110 | 24 | 660,493 | |||
| New York | 0 | 0 | 46 | 410,795 | |||
| Kentucky | 0 | 0 | 40 | 391,573 | |||
| Delaware | 0 | 0 | 5 | 325,048 | |||
| Michigan | 0 | 0 | 5 | 225,224 | |||
| Massachusetts | 0 | 0 | 10 | 199,459 | |||
| New Mexico | 3 | 485 | 76 | 184,925 | |||
| Illinois | 0 | 0 | 43 | 170,331 | |||
| Oklahoma | 0 | 0 | 36 | 159,097 | |||
| Iowa | 1 | 266 | 57 | 120,380 | |||
| West Virginia | 0 | 0 | 29 | 97,629 | |||
| Wisconsin | 0 | 0 | 36 | 90,919 | |||
| North Dakota | 0 | 0 | 4 | 69,457 | |||
| Maryland | 0 | 0 | 9 | 64,518 | |||
| Alabama | 0 | 0 | 7 | 40,341 | |||
| Tennessee | 0 | 0 | 3 | 38,643 | |||
| Virginia | 0 | 0 | 19 | 32,390 | |||
| Indiana | 0 | 0 | 16 | 24,957 | |||
| Washington | 0 | 0 | 19 | 23,682 | |||
| Mississippi | 0 | 0 | 10 | 23,395 | |||
| Wyoming | 0 | 0 | 7 | 20,849 | |||
| South Dakota | 0 | 0 | 15 | 18,942 | |||
| Montana | 0 | 0 | 21 | 6,292 | |||
| Arkansas | 0 | 0 | 2 | 6,204 | |||
| North Carolina | 0 | 0 | 4 | 3,867 | |||
| New Hampshire | 0 | 0 | 6 | 3,119 | |||
| Ohio | 0 | 0 | 3 | 1,930 | |||
| Maine | 0 | 0 | 3 | 913 | |||
| South Carolina | 0 | 0 | 3 | 757 | |||
| Oregon | 0 | 0 | 5 | 739 | |||
| Connecticut | 0 | 0 | 4 | 323 | |||
| Rhode Island | 0 | 0 | 1 | 225 | |||
| Georgia | 1 | 112 | 1 | 112 | |||
| Idaho | 0 | 0 | 1 | 65 | |||
Utilities with the highest amounts of selenium, 2015
| Utility | Location | Tests | Average level | People served |
|---|---|---|---|---|
| Valley Estates | Shallowater, TX | 4 of 4 | 121.0 ppb | 70 |
| Heartland House | Lubbock, TX | 3 of 3 | 101.5 ppb | 26 |
| Leisure Mountain Mobile Home Park | Tijeras, NM | 4 of 4 | 101.0 ppb | 162 |
| Vista Hills Mutual Water Company | Lompoc, CA | 1 of 2 | 60.0 ppb | 75 |
| Glade, City of | Phillipsburg, KS | 1 of 1 | 57.0 ppb | 94 |
| Falfurrias Utility Board | Falfurrias, TX | 5 of 5 | 56.3 ppb | 7,500 |
| Sky Ranch Estates | Sandy Valley, NV | 1 of 1 | 55.0 ppb | 110 |
| Glen Elder, City of | Glen Elder, KS | 4 of 4 | 49.3 ppb | 435 |
| Asgard Subdivision Wa | Silt, CO | 5 of 5 | 48.8 ppb | 80 |
| Town North Village Water System | Lubbock, TX | 8 of 8 | 48.7 ppb | 335 |
| Riverview Communities Lp South | Warren, PA | 1 of 1 | 48.2 ppb | 100 |
| Rio Manor Mutual Water Company | Oxnard, CA | 2 of 2 | 48.0 ppb | 900 |
| Ken Mar Gardens | Arroyo Grande, CA | 1 of 1 | 47.0 ppb | 84 |
| Beverly, City of | Beverly, KS | 2 of 3 | 46.7 ppb | 159 |
| Rooks County Rural Water District 1 | Woodston, KS | 1 of 1 | 45.0 ppb | 87 |
| Town North Estates | Lubbock, TX | 4 of 4 | 42.8 ppb | 210 |
| Burr Oak, City of | Burr Oak, KS | 1 of 1 | 42.0 ppb | 168 |
| Town of Woodsboro | Woodsboro, TX | 3 of 3 | 41.8 ppb | 1,494 |
| Whippoorwill Subdivision | Valdosta, GA | 1 of 1 | 41.0 ppb | 112 |
| City of Wilson | Wilson, TX | 5 of 5 | 40.1 ppb | 485 |
| Dedham Water Supply | Dedham, IA | 1 of 1 | 40.0 ppb | 266 |
| City of New Home | New Home, TX | 1 of 1 | 40.0 ppb | 334 |
| Floyd Ws Village of | Floyd, NM | 1 of 1 | 40.0 ppb | 113 |
| Welch Water Supply Corporation | Welch, TX | 1 of 1 | 38.0 ppb | 315 |
| Saticoy Country Club-city Of Ventura | Ventura, CA | 2 of 2 | 37.5 ppb | 150 |
| Klondike Independent School District | Lamesa, TX | 1 of 1 | 37.0 ppb | 231 |
| Chandlers Valley Mobile Home Park | Sheffield, PA | 1 of 1 | 36.4 ppb | 50 |
| Spring Meadow Mobile Home Park | Midland, TX | 1 of 1 | 36.0 ppb | 189 |
| Cox Addition Water System | Lubbock, TX | 4 of 4 | 35.1 ppb | 126 |
| Bentley, City of | Bentley, KS | 1 of 1 | 35.0 ppb | 524 |
| Utility | Location | Tests | Average level | People served |
|---|---|---|---|---|
| City of Dodge City | Dodge City, KS | 1 of 1 | 23.0 ppb | 28,117 |
| Buckeye Water District 50* | Deville, LA | 10 of 10 | 17.7 ppb | 10,287 |
| City of Davis* | Davis, CA | 16 of 22 | 16.5 ppb | 67,298 |
| City of Salina* | Salina, KS | 1 of 1 | 16.0 ppb | 47,867 |
| Monroe* | Monroe, MI | 1 of 1 | 16.0 ppb | 48,726 |
| Ventura Waterworks District No. 8 - Simi Valley | Simi Valley, CA | 2 of 2 | 14.0 ppb | 86,000 |
| Morro Bay PW Department - Water Division | Morro Bay, CA | 8 of 8 | 13.0 ppb | 10,327 |
| City of Midland | Midland, TX | 2 of 5 | 12.9 ppb | 119,385 |
| City of Andrews | Andrews, TX | 1 of 1 | 12.0 ppb | 11,088 |
| Camarillo Water Department | Camarillo, CA | 1 of 1 | 12.0 ppb | 45,500 |
| Montecito Water District | Santa Barbara, CA | 4 of 4 | 10.8 ppb | 13,500 |
| Pennsville Twsp. Water Depart. | Pennsville, NJ | 4 of 4 | 10.7 ppb | 13,500 |
| Kingman Municipal Water* | Kingman, AZ | 6 of 6 | 10.7 ppb | 45,000 |
| City of Woodland | Woodland, CA | 3 of 3 | 10.2 ppb | 56,464 |
| City of Great Bend | Great Bend, KS | 7 of 7 | 9.99 ppb | 15,840 |
| Center Twp Water Authority* | Aliquippa, PA | 1 of 1 | 9.30 ppb | 12,500 |
| City of Brentwood | Brentwood, CA | 6 of 8 | 9.15 ppb | 53,278 |
| Harris County MUD 157* | Houston, TX | 1 of 1 | 8.70 ppb | 10,956 |
| Nueces County WCID 3* | Robstown, TX | 1 of 1 | 8.50 ppb | 14,607 |
| City of Haysville | Haysville, KS | 1 of 1 | 8.50 ppb | 11,112 |
| Military Highway WSC - Progreso | Progreso, TX | 1 of 1 | 8.10 ppb | 11,136 |
| City of Hialeah | Hialeah, FL | 1 of 1 | 7.70 ppb | 229,900 |
| City of Abilene* | Abilene, TX | 3 of 3 | 7.67 ppb | 123,886 |
| California Water Service Company - Hermosa / Redondo Beach | San Jose, CA | 1 of 1 | 7.40 ppb | 95,605 |
| Clearwater Water System* | Clearwater, FL | 3 of 3 | 7.27 ppb | 110,000 |
| City of Beeville* | Beeville, TX | 1 of 1 | 7.10 ppb | 15,039 |
| City of Show Low | Show Low, AZ | 1 of 1 | 6.80 ppb | 15,716 |
| City of Hays* | Hays, KS | 1 of 1 | 6.70 ppb | 21,044 |
| McAllen Public Utility* | Mcallen, TX | 2 of 2 | 6.60 ppb | 163,302 |
| Pinery Wwd | Parker, CO | 1 of 1 | 6.40 ppb | 10,800 |
* 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 Selenium, but it likely has the contaminant in its water supply.