waterbycounty
Compiled federal source snapshot

Oklahoma Water Quality

Drinking water data for all 76 counties.

Avg SDWIS Compliance Index

15.2

Most Common Five-Year SDWIS Compliance Band

F

Counties with Data

76

of 76 total

County water atlas

Oklahoma water signals by county

A state-level 2.5D view across drinking-water compliance, watershed impairment, monitoring density, and streamflow snapshot context. Pin any county, switch layers, then use the lens controls to compare index ranges, recorded violation rates, or impaired watersheds without leaving the page.

Counties

76

Avg SDWIS index

15.2

Watersheds

60

ATTAINS counties

Monitoring

76

58 fresh USGS snapshots

State atlas layers combine EPA SDWIS health-based violations, EPA ATTAINS 303(d) impairment assessments, EPA Water Quality Portal monitoring sites, and representative USGS NWIS streamflow gauges. Streamflow values appear only for fresh pipeline snapshots, not as a continuously updated stream. County pages include the observation time and year.

Prepared by ByCounty Editorial TeamPublished by WaterByCounty

Multi-source coverage in Oklahoma

Beyond Drinking Water

EPA SDWIS

76/ 76

counties with drinking-water compliance data

4,750 health violations statewide (5yr)

EPA ATTAINS

81.3%

avg impaired across 60 counties

124 of 159 assessed bodies impaired

EPA WQP

1,084

monitoring sites across 76 counties

854,368 total readings (5yr window)

USGS NWIS

58

counties with a fresh pipeline snapshot

0 above58 below

State atlas notes

What stands out in Oklahoma

County water quality is not one number. The strongest read comes from comparing drinking-water compliance against watershed impairment, monitoring density, and streamflow context. Use these signals as a starting point, then open any county profile for source-level detail.

Compliance spread

Harper County has the highest value in the published state SDWIS Compliance Index table at 86.2/100, while Choctaw County has the lowest at 0.6/100. That is a 85.6 point gap inside one state.

Zero health violations

2

3+ health violations

72

Watershed pressure

The atlas impairment layer points to counties where assessed water bodies are most likely to miss state quality standards. Assessment density varies, so compare the percentage with the number of assessed bodies on the county page.

Adair County100.0%Alfalfa County100.0%Atoka County100.0%

Monitoring hubs

Ottawa County106 sitesCaddo County48 sitesCleveland County44 sites

Lowest flow reads

Harper County0%Seminole County0%Major County0%

Highest fresh streamflow pipeline snapshots: Rogers County (56%, observation 2026), Johnston County (52%, observation 2026), Cherokee County (39%, observation 2026). These are source-data observations, not household tap-water conclusions.

All Oklahoma Counties

CountySDWIS Compliance Index
Harper County86.2
Love County86.2
Tulsa County69.8
Oklahoma County61.6
Pontotoc County37.0
Comanche County35.5
Beckham County35.3
Garfield County34.4
Logan County33.8
Texas County33.4
McClain County32.6
Mayes County32.4
Cleveland County32.0
Payne County32.0
Woodward County30.8
Custer County29.7
Creek County24.9
Cimarron County21.4
Rogers County21.3
Sequoyah County20.9
Ottawa County20.5
Woods County18.7
Stephens County18.5
Kay County17.6
Ellis County15.9
Adair County15.3
Canadian County15.3
Carter County13.4
Bryan County13.0
Beaver County12.3
Grady County11.3
Murray County10.0
Johnston County9.8
Delaware County9.6
Washington County9.6
Dewey County9.4
Craig County8.9
Blaine County8.5
Alfalfa County8.3
Cherokee County7.7
Washita County7.2
Okfuskee County6.5
Pottawatomie County5.8
Roger Mills County5.2
Wagoner County5.2
Greer County5.0
Noble County4.9
Muskogee County4.8
Lincoln County4.5
Marshall County4.5
McCurtain County4.5
Garvin County4.1
Le Flore County4.1
Jackson County3.9
Coal County3.8
Caddo County3.7
Okmulgee County3.6
Kingfisher County2.9
Kiowa County2.9
Grant County2.8
Pittsburg County2.6
McIntosh County2.3
Hughes County2.1
Cotton County1.8
Latimer County1.7
Seminole County1.7
Major County1.6
Jefferson County1.5
Pawnee County1.5
Nowata County1.3
Tillman County1.3
Haskell County1.0
Osage County0.9
Atoka County0.7
Pushmataha County0.7
Choctaw County0.6

Frequently Asked Questions

Which Oklahoma county has the highest SDWIS Compliance Index?
Harper County has the highest SDWIS Compliance Index in the published Oklahoma cohort at 86.2/100. This WaterByCounty relative comparison is not an EPA score and does not establish current conditions for a utility or address.
What does the Five-Year SDWIS Compliance Band mean?
The band is derived only from each county aggregation's recorded health-violation rate per 100,000 people served for the stated five-year source window. It is separate from the relative SDWIS Compliance Index and is not a current determination for a specific utility or address.
What does EPA ATTAINS report across Oklahoma?
Across 60 published Oklahoma county records with EPA ATTAINS data, 124 of 159 assessed water bodies are listed as impaired. This is a watershed assessment and does not describe finished household tap water.
Which USGS streamflow records are shown across Oklahoma?
WaterByCounty has 58 fresh USGS pipeline snapshots in the published Oklahoma cohort. Each county page shows its observation timestamp and year. A pipeline snapshot is not a continuously updated reading or a tap-water safety measure.
Where can Oklahoma residents find current official information?
Review the applicable utility's Consumer Confidence Report, active notices, and the state drinking-water agency. WaterByCounty's county-level historical aggregations do not establish the current status of a specific utility, address, private well, or household plumbing system.
What does Water Quality Portal monitoring volume show in Oklahoma?
The published county records contain 854,368 results from 1,084 monitoring locations in the site's five-year aggregation. Monitoring volume does not by itself indicate better or worse water quality.

Data Sources

Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. The WaterByCounty SDWIS Compliance Index reflects the recorded rate and is not an EPA score.

Disclaimer: This data is informational only. It is not health, legal, or professional advice. For concerns about your specific water supply, contact your local water utility.

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