Nitrate in Oklahoma well water
In Oklahoma, 35% of 10,968 tested private well samples exceeded the EPA limit for nitrate (10 mg/L).
Nitrate reaches wells from fertilizer, septic systems and manure. Above the limit it can cause methemoglobinemia (blue baby syndrome) in infants under six months, and long-term exposure is associated with some cancers. Shallow and dug wells near farmland or dense septic systems are most at risk.
Check your nitrate number
Type the value from your lab report. It is compared to the EPA limit, the same way the full interpretation does it.
Test your Oklahoma well for nitrate
Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.
Order the Tap Score well water test kit, from $209Already tested? Upload the report
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Systems that remove nitrate
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Some links below are affiliate links. If you buy through one, the merchant pays us a commission at no extra cost to you. It does not change which products we list or what the data says.
For nitrate
Under-sink reverse osmosis system
under-sink or countertop, about $300
Look for NSF/ANSI 58 certification listing the contaminant you need removed.
For nitrate
Aquasana SmartFlow reverse osmosis
under-sink or countertop, about $225
Certified to NSF/ANSI 58 and 53 to reduce arsenic (96%, pentavalent), fluoride (90%), lead (99%), nitrate, nitrite and PFOA/PFOS at the kitchen tap, with a remineralizer.
Rather have it installed and sized for your well? Book a free in-home water test with a licensed local company.
Where to get a well tested for nitrate in Oklahoma: certified labs, state programs and prices.
By county, from individual samples
Public monitoring samples against the EPA limit (10 mg/L); counties with at least 30 samples.
| County | Above EPA limit | Samples | Detected | Median | Highest |
|---|---|---|---|---|---|
| Major | 1,286 | 100% | 13.5 | 91 mg/L | |
| Harper | 601 | 100% | 14 | 68.8 mg/L | |
| Kingfisher | 1,127 | 100% | 12 | 300 mg/L | |
| Alfalfa | 42 | 98% | 12.5 | 83 mg/L | |
| Garfield | 82 | 99% | 10.3 | 92.6 mg/L | |
| Grady | 210 | 98% | 9.65 | 352 mg/L | |
| Woods | 91 | 99% | 8.1 | 89 mg/L | |
| Blaine | 127 | 98% | 6.7 | 142 mg/L | |
| Caddo | 488 | 100% | 8 | 279 mg/L | |
| Custer | 114 | 100% | 7.47 | 100 mg/L | |
| Beckham | 41 | 100% | 5.8 | 71 mg/L | |
| Texas | 809 | 100% | 6.1 | 135 mg/L | |
| Grant | 36 | 100% | 6.3 | 100 mg/L | |
| Logan | 132 | 89% | 3.6 | 177 mg/L | |
| Pontotoc | 195 | 95% | 2.59 | 73.1 mg/L |
- Minco CCD, Grady County79% of 81
- Fairview CCD, Major County78% of 890
- Laverne CCD, Harper County69% of 591
- Enid CCD, Garfield County69% of 48
- Hennessey CCD, Kingfisher County59% of 1,090
- Okeene CCD, Blaine County55% of 75
- Thomas CCD, Custer County53% of 74
- Guymon CCD, Texas County53% of 232
- Hydro CCD, Caddo County49% of 140
- East Major CCD, Major County48% of 396
- Anadarko CCD, Caddo County47% of 43
- Carnegie CCD, Caddo County46% of 59
- South Woods CCD, Woods County44% of 72
- South Ellis CCD, Ellis County41% of 66
- South Central Pontotoc CCD, Pontotoc County39% of 119
- Guthrie CCD, Logan County35% of 78
- Hooker CCD, Texas County34% of 447
- Rush Springs CCD, Grady County33% of 75
- Woodward CCD, Woodward County30% of 73
- North Beaver CCD, Beaver County30% of 579
Sources
- Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. nitrate counts and shares are listed on each county and town page with their sources.
Analysis: Nitrate in private wells, decade by decade, from the same public records.