Is nitrate a problem in Oklahoma drinking water?

Nitrate was detected above the EPA limit of 10 mg/L (as nitrogen) in 21 ZIP codes across Oklahoma. Check the table above for specific areas. Consider Reverse Osmosis or Ion Exchange if your ZIP is affected.

How widespread is nitrate in Oklahoma water?

Nitrate was detected in 66 ZIP codes across Oklahoma. 21 ZIPs exceeded the EPA limit. See the table above for details.

Nitrate · Oklahoma

Nitrate in Oklahoma Drinking Water — 66 ZIPs Tested

EPA data analysis for nitrate in Oklahoma drinking water systems

ZIPs with Detections

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	13.6 ppm	10 ppm	Exceeds
2	73040	Geary	13.6 ppm	10 ppm	Exceeds
3	73550	Hollis	13.2 ppm	10 ppm	Exceeds
4	73571	Vinson	13.2 ppm	10 ppm	Exceeds
5	73743	Hillsdale	12.5 ppm	10 ppm	Exceeds
6	73753	Kremlin	12.5 ppm	10 ppm	Exceeds
7	74636	Deer Creek	11.1 ppm	10 ppm	Exceeds
8	73632	Cordell	10.5 ppm	10 ppm	Exceeds
9	73661	Rocky	10.5 ppm	10 ppm	Exceeds
10	73939	Goodwell	10.2 ppm	10 ppm	Exceeds
11	73772	Watonga	9.62 ppm	10 ppm	Within Limit
12	73544	Gould	9.52 ppm	10 ppm	Within Limit
13	73560	Olustee	9.52 ppm	10 ppm	Within Limit
14	73744	Hitchcock	9.26 ppm	10 ppm	Within Limit
15	73056	Marshall	9.18 ppm	10 ppm	Within Limit
16	73832	Arnett	9.02 ppm	10 ppm	Within Limit
17	73840	Fargo	9.02 ppm	10 ppm	Within Limit
18	73857	Sharon	9.02 ppm	10 ppm	Within Limit
19	73942	Guymon	8.9 ppm	10 ppm	Within Limit
20	73554	Mangum	8.89 ppm	10 ppm	Within Limit

Lowest Nitrate Levels in Oklahoma

ZIP Code	City	Level Detected
73042	Gracemont	5.01 ppm
73011	Bradley	5.01 ppm
73004	Amber	5.01 ppm
73572	Walters	5.24 ppm
73568	Temple	5.24 ppm
73543	Geronimo	5.24 ppm
73540	Faxon	5.24 ppm
73531	Devol	5.24 ppm
73932	Beaver	5.48 ppm
73931	Balko	5.48 ppm

Cities with Nitrate Data in Oklahoma

9 cities in Oklahoma have nitrate testing data available.

Alva Blanchard Chickasha Guymon Noble Piedmont Tecumseh Tuttle Yukon

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.

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