Nitrate · Oklahoma

Nitrate in Oklahoma Drinking Water — 66 ZIPs Tested

EPA data analysis for nitrate in Oklahoma drinking water systems

ZipCheckup tracks Nitrate in Oklahoma drinking water: 66 ZIP codes with detected levels on record. 21 ZIP codes exceed the EPA limit (10 mg/L (as nitrogen)). Nitrate carries a high health-risk designation.

66
ZIPs with Detections
21
ZIPs with Violations
2.7%
Violation Rate
10 mg/L (as nitrogen)
EPA Limit
High
Health Risk
Reverse Osmosis or Ion Exchange
Best Filter Method

Nitrate Contamination in Oklahoma

ZipCheckup analyzed drinking water data across 771 ZIP codes in Oklahoma for nitrate contamination. 66 ZIP codes have reported nitrate detections, and 21 have EPA violations on record.

The violation rate for nitrate in Oklahoma is 2.7% of all ZIP codes — roughly in line with the national average.

EPA Standard for Nitrate

The EPA maximum contaminant level (MCL) for nitrate is 10 mg/L (as nitrogen), governed by the National Primary Drinking Water Regulations. Water systems that exceed this limit must take corrective action and notify consumers.

Worst ZIP Codes for Nitrate in Oklahoma

These ZIP codes reported the highest nitrate levels in Oklahoma based on CCR reports and EPA data:

Lowest Nitrate Levels in Oklahoma

These ZIP codes had the lowest reported nitrate detections in Oklahoma:

Health Effects of Nitrate

How to Remove Nitrate From Drinking Water

The most effective treatment for nitrate removal is Reverse Osmosis or Ion Exchange. Look for filters certified under NSF 53 / NSF 58 standards.

Check Your ZIP Code

Use the ZipCheckup water quality search to see nitrate data for your specific water system in Oklahoma.

Worst ZIP Codes for Nitrate in Oklahoma

Ranked by highest nitrate detection level.

Rank ZIP Code City Level Detected EPA Limit Status
1 73014 Calumet 13600 ppb 10000 ppb Exceeds
2 73040 Geary 13600 ppb 10000 ppb Exceeds
3 73550 Hollis 13200 ppb 10000 ppb Exceeds
4 73571 Vinson 13200 ppb 10000 ppb Exceeds
5 73743 Hillsdale 12500 ppb 10000 ppb Exceeds
6 73753 Kremlin 12500 ppb 10000 ppb Exceeds
7 74636 Deer Creek 11100 ppb 10000 ppb Exceeds
8 73632 Cordell 10500 ppb 10000 ppb Exceeds
9 73661 Rocky 10500 ppb 10000 ppb Exceeds
10 73939 Goodwell 10200 ppb 10000 ppb Exceeds
11 73772 Watonga 9620 ppb 10000 ppb Within Limit
12 73544 Gould 9520 ppb 10000 ppb Within Limit
13 73560 Olustee 9520 ppb 10000 ppb Within Limit
14 73744 Hitchcock 9260 ppb 10000 ppb Within Limit
15 73056 Marshall 9180 ppb 10000 ppb Within Limit
16 73832 Arnett 9020 ppb 10000 ppb Within Limit
17 73840 Fargo 9020 ppb 10000 ppb Within Limit
18 73857 Sharon 9020 ppb 10000 ppb Within Limit
19 73942 Guymon 8900 ppb 10000 ppb Within Limit
20 73554 Mangum 8890 ppb 10000 ppb Within Limit

Lowest Nitrate Levels in Oklahoma

ZIP Code City Level Detected
73042 Gracemont 5010 ppb
73011 Bradley 5010 ppb
73004 Amber 5010 ppb
73572 Walters 5240 ppb
73568 Temple 5240 ppb
73543 Geronimo 5240 ppb
73540 Faxon 5240 ppb
73531 Devol 5240 ppb
73932 Beaver 5480 ppb
73931 Balko 5480 ppb

Cities with Nitrate Data in Oklahoma

9 cities in Oklahoma have nitrate testing data available.

Oklahoma Water Quality Overview: See statewide water quality rankings on the Oklahoma water quality page.
Learn more about Nitrate: Read the full guide on Nitrate in drinking water.
Home → Contaminants → Nitrate → Oklahoma

How to cite this page

APA ZipCheckup. (2026). Nitrate in Oklahoma Drinking Water — 66 ZIPs Tested. https://zipcheckup.com/contaminants/nitrates/oklahoma/
BibTeX 
@misc{zipcheckup-contaminants-nitrates-oklahoma,
  author = {{ZipCheckup}},
  title  = {{Nitrate in Oklahoma Drinking Water — 66 ZIPs Tested}},
  year   = {2026},
  url    = {https://zipcheckup.com/contaminants/nitrates/oklahoma/}
}

Data as of July 2026.

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