Tapcensus

Selenium violations in Oklahoma

20 active public water systems in Oklahoma had a Selenium violation in the past three years. What Selenium is and why it matters.

Health effects: Chronic exposure above the MCL causes selenosis — characterized by hair and nail loss, peripheral neuropathy, fatigue, and gastrointestinal disturbance. Liver damage can occur with prolonged high intake. The margin between nutritional requirement and toxic dose is narrow, making the MCL an important threshold.

Systems with a Selenium violation

Latest quarter first, then largest first
SystemServesStatusRules violated, 3 yrUnresolved
Elgin Pwa
Comanche County
3,300 9 1
Prague
Lincoln County
2,395 7 1
Hooker
Texas County
1,788 5 1
Oilton
Creek County
1,435 14 5
Seminole Co. Rwd #7
Seminole County
450 3 1
Carmen Public Works Authority
Alfalfa County
355 11 3
Spring Cove RV Park&marina Onlake Hudson
Mayes County
225 10 2
Harper CO Rwd #1
Harper County
198 10 1
Willow
Greer County
114 8 1
Peppers Ranch
Logan County
99 6 1
Surrey Hills
Texas County
87 14 4
Freedom Farms
Cleveland County
85 7 3
Oak Ridge Estates I & II Water Assoc.
Delaware County
62 11 4
Red Wagon MHP
Payne County
46 7 2
Shady Acres Custer County
Custer County
40 8 2
Timber Creek MHP East & West
Pottawatomie County
40 10 2
Canoe Mountain Water System
Cherokee County
37 12 2
Country Haven MHP
Oklahoma County
30 8 2
Oklahoma City North Canadian Stp
Oklahoma County
30 7 1
Grandview Village
Delaware County
24 5 0
About this data

A system is counted once if any of its violations in the past three years involved Selenium, including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not Selenium alone.

Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Oklahoma records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.