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.
2015-2017:
49
states detected
6,180
utilities detected
68 million
people served
13
states over health guideline
61
utilities over health guideline
21,572
people served over health guideline
6
states over legal limit
16
utilities over legal limit
3,556
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
EWG Health Guideline 30 ppb
The EWG 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.
EPA Maximum Contaminant
Level (MCL) 50 ppb
The legal limit for selenium, established in 1991, was based on human epidemiological studies of populations exposed to naturally occurring selenium in drinking water. This limit does not include any additional consideration of children’s health.
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 | 22 | 13,491 | 1,583 | 16,566,017 | |||
California | 11 | 2,409 | 387 | 10,920,175 | |||
Florida | 0 | 0 | 514 | 8,269,001 | |||
Colorado | 4 | 518 | 388 | 3,292,477 | |||
New Jersey | 0 | 0 | 225 | 3,046,503 | |||
Arizona | 0 | 0 | 68 | 2,791,899 | |||
Utah | 0 | 0 | 345 | 2,775,934 | |||
Missouri | 0 | 0 | 77 | 2,584,995 | |||
Kansas | 10 | 2,471 | 647 | 2,382,709 | |||
Nevada | 1 | 110 | 46 | 2,048,112 | |||
Louisiana | 0 | 0 | 108 | 1,723,552 | |||
Pennsylvania | 4 | 264 | 115 | 1,534,755 | |||
Hawaii | 0 | 0 | 6 | 963,268 | |||
Oklahoma | 0 | 0 | 64 | 952,300 | |||
Nebraska | 0 | 0 | 9 | 883,441 | |||
New York | 1 | 1,100 | 168 | 843,244 | |||
Wisconsin | 0 | 0 | 157 | 712,345 | |||
New Mexico | 3 | 485 | 199 | 633,073 | |||
Kentucky | 0 | 0 | 81 | 608,612 | |||
Illinois | 1 | 221 | 138 | 585,364 | |||
Washington | 0 | 0 | 129 | 497,863 | |||
Delaware | 0 | 0 | 25 | 471,013 | |||
Massachusetts | 0 | 0 | 16 | 285,189 | |||
Alabama | 0 | 0 | 20 | 282,228 | |||
Indiana | 1 | 47 | 48 | 245,967 | |||
Mississippi | 0 | 0 | 64 | 218,518 | |||
Michigan | 0 | 0 | 6 | 196,697 | |||
South Dakota | 0 | 0 | 20 | 189,554 | |||
North Dakota | 0 | 0 | 37 | 180,465 | |||
Connecticut | 0 | 0 | 16 | 174,042 | |||
Wyoming | 0 | 0 | 94 | 150,113 | |||
West Virginia | 0 | 0 | 65 | 146,711 | |||
Maryland | 0 | 0 | 21 | 101,615 | |||
South Carolina | 0 | 0 | 13 | 99,968 | |||
Iowa | 1 | 266 | 54 | 99,094 | |||
Tennessee | 0 | 0 | 9 | 95,989 | |||
Minnesota | 0 | 0 | 2 | 65,041 | |||
Virginia | 0 | 0 | 32 | 48,100 | |||
Montana | 0 | 0 | 85 | 43,773 | |||
Arkansas | 0 | 0 | 9 | 35,968 | |||
Ohio | 0 | 0 | 16 | 31,755 | |||
Georgia | 1 | 122 | 6 | 29,158 | |||
Idaho | 0 | 0 | 18 | 28,206 | |||
North Carolina | 1 | 68 | 10 | 21,804 | |||
Rhode Island | 0 | 0 | 4 | 10,431 | |||
New Hampshire | 0 | 0 | 19 | 4,990 | |||
Oregon | 0 | 0 | 12 | 4,586 | |||
Maine | 0 | 0 | 4 | 2,210 | |||
Alaska | 0 | 0 | 1 | 53 |
Filtering technologies that reduce selenium

Reverse Osmosis
Utilities with the highest amounts of selenium, 2015-2017
Utility | Location | Tests | Average level | People served |
---|---|---|---|---|
Alpine Springs Mobile Home Park | Palmdale, CA | 1 of 1 | 162.0 ppb | 120 |
Sunnyside Farms Mutual Water Company | Palmdale, CA | 1 of 1 | 107.0 ppb | 326 |
Valley Estates | Shallowater, TX | 7 of 7 | 106.0 ppb | 70 |
Heartland House | Lubbock, TX | 11 of 12 | 85.2 ppb | 26 |
Burr Oak, City of | Burr Oak, KS | 6 of 6 | 61.2 ppb | 168 |
U.s.n., San Nicolas Island | Point Mugu, CA | 5 of 6 | 60.8 ppb | 250 |
Vista Hills Mutual Water Company | Lompoc, CA | 1 of 2 | 60.0 ppb | 75 |
Montclair Condominiums | Poughkeepsie, NY | 1 of 1 | 60.0 ppb | 1,100 |
Sutter County Wwd #1 (robbins) | Yuba City, CA | 1 of 2 | 55.0 ppb | 350 |
Leisure Mountain Mobile Home Park | Tijeras, NM | 11 of 11 | 54.8 ppb | 162 |
Dana Ranch | Emeryville, CA | 1 of 1 | 53.0 ppb | 34 |
South Mountain Mutual Water Company | Santa Paula, CA | 5 of 5 | 52.4 ppb | 45 |
Glen Elder, City of | Glen Elder, KS | 13 of 13 | 51.8 ppb | 435 |
Sky Ranch Estates | Sandy Valley, NV | 4 of 4 | 51.2 ppb | 110 |
Rosa Joint Ventures Water System | Ignacio, NM | 6 of 6 | 50.5 ppb | 210 |
Resthaven Mobile Home Park | Paso Robles, CA | 23 of 23 | 50.3 ppb | 75 |
Falfurrias Utility Board | Falfurrias, TX | 16 of 16 | 49.8 ppb | 7,500 |
Ken Mar Gardens | Arroyo Grande, CA | 4 of 4 | 49.5 ppb | 84 |
Riverview Communities Lp South | Warren, PA | 1 of 1 | 48.2 ppb | 100 |
Town North Village Water System | Lubbock, TX | 24 of 24 | 48.1 ppb | 335 |
Rio Manor Mutual Water Company | Oxnard, CA | 2 of 2 | 48.0 ppb | 900 |
Dedham Water Supply | Dedham, IA | 4 of 4 | 47.5 ppb | 266 |
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 |
King Ranch Laureles Division | Kingsville, TX | 1 of 1 | 44.8 ppb | 60 |
Asgard Subdivision Wa | Silt, CO | 13 of 13 | 44.0 ppb | 80 |
Pecan Grove Mobile Home Park | San Antonio, TX | 1 of 1 | 44.0 ppb | 81 |
Catarina Water Supply Corporation | Carrizo Springs, TX | 1 of 1 | 43.4 ppb | 252 |
Heritage Park Apartments | Lafayette, IN | 1 of 1 | 42.0 ppb | 47 |
Whippoorwill Subdivision | Valdosta, GA | 1 of 1 | 41.0 ppb | 122 |
Floyd Ws Village of | Floyd, NM | 1 of 1 | 40.0 ppb | 113 |
Aurora, City of | Aurora, KS | 1 of 1 | 40.0 ppb | 60 |
City of New Home | New Home, TX | 1 of 1 | 40.0 ppb | 334 |
Texas Boys Ranch | Lubbock, TX | 1 of 1 | 40.0 ppb | 50 |
Town North Estates | Lubbock, TX | 12 of 12 | 39.8 ppb | 210 |
City of Wilson | Wilson, TX | 13 of 13 | 38.1 ppb | 485 |
Ankrom Acres Mobile Home Park | Clinton, PA | 1 of 1 | 38.0 ppb | 24 |
Welch Water Supply Corporation | Welch, TX | 1 of 1 | 38.0 ppb | 315 |
Wimberley Oaks Water Supply Corporation | Wimberley, TX | 1 of 1 | 37.4 ppb | 69 |
Klondike Independent School District | Lamesa, TX | 1 of 1 | 37.0 ppb | 264 |
Chandlers Valley Mobile Home Park | Sheffield, PA | 1 of 1 | 36.4 ppb | 50 |
Fox Creek Farms Water Company | Brimfield, IL | 1 of 1 | 36.0 ppb | 221 |
Spring Meadow Mobile Home Park | Midland, TX | 1 of 1 | 36.0 ppb | 163 |
Riviera WCID | Riviera, TX | 1 of 1 | 35.1 ppb | 729 |
Geuda Springs, City of | Geuda Springs, KS | 1 of 1 | 35.0 ppb | 183 |
Prairie View Ranch WD | Greeley, CO | 2 of 2 | 35.0 ppb | 30 |
Bentley, City of | Bentley, KS | 1 of 1 | 35.0 ppb | 524 |
Greenleaf, City of | Greenleaf, KS | 1 of 1 | 34.0 ppb | 314 |
Pithole Water Association | Cyclone, PA | 1 of 1 | 33.5 ppb | 90 |
Dorsett Place | Austin, TX | 1 of 1 | 33.3 ppb | 42 |
Utility | Location | Tests | Average level | People served |
---|---|---|---|---|
City of Midland | Midland, TX | 11 of 15 | 25.1 ppb | 132,950 |
City of Ocoee | Ocoee, FL | 2 of 2 | 22.4 ppb | 39,239 |
Buckeye Water District 50 | Deville, LA | 10 of 10 | 17.7 ppb | 10,287 |
City of Davis* | Davis, CA | 40 of 59 | 16.0 ppb | 67,298 |
Monroe* | Monroe, MI | 1 of 1 | 16.0 ppb | 48,726 |
City of Salina* | Salina, KS | 3 of 3 | 13.7 ppb | 47,867 |
Morro Bay PW Department - Water Division | Morro Bay, CA | 8 of 8 | 13.0 ppb | 10,327 |
Ventura Waterworks District No. 8 - Simi Valley | Simi Valley, CA | 3 of 4 | 12.0 ppb | 86,000 |
Camarillo Water Department | Camarillo, CA | 1 of 1 | 12.0 ppb | 45,500 |
City of Andrews | Andrews, TX | 2 of 2 | 12.0 ppb | 11,088 |
City of Show Low | Show Low, AZ | 12 of 13 | 11.6 ppb | 17,139 |
Montecito Water District | Santa Barbara, CA | 4 of 4 | 10.8 ppb | 13,500 |
Shawnee County RWD 4C* | Topeka, KS | 2 of 2 | 10.6 ppb | 12,000 |
City of Woodland | Woodland, CA | 3 of 3 | 10.2 ppb | 56,464 |
Kingman Municipal Water | Kingman, AZ | 7 of 7 | 9.91 ppb | 45,000 |
City of Kingsville* | Kingsville, TX | 6 of 6 | 9.13 ppb | 32,736 |
City of Great Bend | Great Bend, KS | 9 of 9 | 8.70 ppb | 15,840 |
Verona Water Department* | Chatham, NJ | 2 of 2 | 8.59 ppb | 13,641 |
City of Haysville | Haysville, KS | 1 of 1 | 8.50 ppb | 11,112 |
City of Brentwood | Brentwood, CA | 15 of 21 | 8.12 ppb | 53,278 |
City of Liberal | Liberal, KS | 8 of 8 | 7.58 ppb | 21,012 |
City of Dodge City | Dodge City, KS | 13 of 14 | 7.41 ppb | 28,117 |
California Water Service Company - Hermosa / Redondo Beach | San Jose, CA | 1 of 1 | 7.40 ppb | 95,605 |
Arizona Water Company - Pinal Valley* | Phoenix, AZ | 9 of 9 | 7.18 ppb | 88,019 |
Horizon Regional MUD | Horizon City, TX | 2 of 2 | 7.00 ppb | 32,088 |
Fillmore Water Department | Fillmore, CA | 2 of 3 | 7.00 ppb | 15,222 |
Northwest Park MUD | Houston, TX | 3 of 4 | 6.90 ppb | 17,406 |
Pennsville Twsp. Water Depart. | Pennsville, NJ | 6 of 7 | 6.82 ppb | 13,500 |
Waialua | Honolulu, HI | 1 of 1 | 6.70 ppb | 13,447 |
St. Lucie West Utilities* | Port St. Lucie, FL | 1 of 1 | 6.70 ppb | 16,795 |
City of Hays* | Hays, KS | 1 of 1 | 6.70 ppb | 21,044 |
City of Patterson | Patterson, CA | 7 of 7 | 6.57 ppb | 20,560 |
City of McPherson* | Mcpherson, KS | 1 of 1 | 6.40 ppb | 13,189 |
Nueces County WCID 3* | Robstown, TX | 3 of 3 | 6.40 ppb | 14,607 |
Santa Paula Water System* | Santa Paula, CA | 24 of 29 | 6.34 ppb | 30,048 |
City of Fredericksburg | Fredericksburg, TX | 4 of 4 | 6.13 ppb | 14,500 |
Eagle Mountain City | Eagle Mountain, UT | 4 of 4 | 6.05 ppb | 24,000 |
City of Fountain | Fountain, CO | 2 of 2 | 5.70 ppb | 21,000 |
Military Highway WSC - Progreso | Progreso, TX | 2 of 2 | 5.55 ppb | 11,136 |
Avalon Water and Sewerage Utilities | Avalon, NJ | 5 of 5 | 5.46 ppb | 39,839 |
Wildwood City Water Department* | Wildwood, NJ | 7 of 7 | 5.46 ppb | 218,472 |
Oxnard Water Department | Oxnard, CA | 9 of 31 | 5.44 ppb | 200,855 |
Harris County FWSD 61* | Houston, TX | 5 of 6 | 5.40 ppb | 17,586 |
City of Newton* | Newton, KS | 1 of 1 | 5.30 ppb | 19,120 |
Moore | Moore, OK | 10 of 23 | 5.12 ppb | 41,138 |
Metropolitan Utilities District* | Omaha, NE | 1 of 1 | 5.12 ppb | 600,000 |
City of Beeville* | Beeville, TX | 3 of 3 | 5.10 ppb | 15,039 |
Paso Robles Water Department | Paso Robles, CA | 22 of 41 | 5.09 ppb | 30,500 |
City of Garden City* | Garden City, KS | 3 of 4 | 5.05 ppb | 27,004 |
Jackson* | Jackson, MI | 1 of 1 | 5.00 ppb | 33,961 |
* 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.