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County water report

Comanche County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Comanche County, Oklahoma.

Water grade

F

Water score

29.2

State rank

#16

of 77

Health violations

97

EPA SDWIS, 5-year lookback

Watershed impaired

100.0%

3 water bodies assessed

Monitoring sites

19

8,880 recent measurements

Live streamflow

20%

Little Washita River near Cement, OK

Water at a glance

Key Water Indicators for Comanche County

EPA SDWIS

Safety Grade

F

Score: 29.2 / 100

EPA SDWIS

Active Violations

97

5-year health-based lookback

EPA ATTAINS

Watershed Health

100% impaired

3 bodies assessed

USGS NWIS

Streamflow Snapshot

20% of mean

Little Washita River near Cement, OK

EPA WQP

Monitoring Sites

19

8,880 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

F

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

29.2/100

Health violations

97

Health-based violations

Violations per 100K served

70.7

Population-normalized SDWIS rate

Editorial analysis

Understanding Comanche County’s Water

Drinking Water Quality Overview

EPA SDWIS

Comanche County's water systems carry a failing grade, scoring 29.2 out of 100. Over the past five years, EPA SDWIS records 97 health-based violations — a pattern that public water utilities are required to disclose and correct.

Watershed Conditions

EPA ATTAINS

Under the Clean Water Act §303(d), EPA ATTAINS tracks whether waterways meet quality standards for drinking, recreation, and aquatic life (reporting cycle: 2022). A large majority — 100.0% — of assessed waterways are impaired (3 of 3 water bodies) across Comanche County's watersheds. The leading impairment causes are chlorophyll-a and turbidity. Impairment does not mean tap water is unsafe — it measures ambient waterway conditions upstream of treatment, not finished drinking water.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T13:45:00.000-05:00) puts Little Washita River at 3.9 cfs — well below its long-term average at 20% of mean — low-flow conditions worth noting for water-dependent ecosystems. Streamflow is a leading indicator of drought stress, sediment load, and dilution capacity: low flows concentrate pollutants and warm water temperatures, stressing aquatic life and, in surface-water-dependent systems, the source water quality for treatment plants.

Monitoring Network

EPA WQP

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. Comanche County has moderate coverage with 19 active monitoring sites with 8,880 recent measurements on record. Predominant monitoring categories include physical and biological, algae, phytoplankton. More monitoring sites generally indicate greater scientific attention to local water conditions — and provide the baseline data that regulators use to set future impairment listings.

Editorial advisory

What the data suggests for Comanche County

Water Verdict

Comanche County, Oklahoma receives a poor water quality assessment with a grade of F and a score of 29.2 out of 100. The water supply has documented quality issues. Residents are strongly encouraged to use filtered or bottled water for drinking and to stay informed about utility improvement plans. Separately, EPA ATTAINS assessments cover 3 water bodies in the county's watershed, with 100.0% listed as impaired under the Clean Water Act — a source-water measure that is tracked independently of tap-water compliance. At the most recent USGS reading, local streamflow was below its historical mean at 19.9% — worth watching in drier seasons.

Violation Context

EPA SDWIS records for Comanche County, Oklahoma show 97 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 70.7 violations per 100,000 people served, this rate is high and signals significant water quality management issues. For independent context, 8,880 water-quality monitoring results have been recorded across the county in the EPA Water Quality Portal over the past five years.

Consumer Guidance

Comanche County has a Grade F compliance record with 97 health-based violations — among the highest levels in the country. Comanche County's drinking-water compliance score is 29.2 out of 100. The violation rate for Comanche County is 70.7 per 100,000 people served. Residents are strongly advised to use a certified NSF 58 reverse-osmosis filter or bottled water for all drinking and cooking until violations are corrected. Contacting the Oklahoma Department of Environmental Quality or Health can expedite utility compliance action. Chlorophyll-A is the leading impairment cause in Comanche County's watershed. With 19 active water-quality monitoring sites in Comanche County, data coverage is strong. A pipeline streamflow snapshot from the Little Washita River gauge is also available on this page.

Regional Context

Comanche County has better water quality than the average county in Oklahoma. Its water score is 13.4 points higher than the state average, indicating stronger water system performance relative to neighboring counties.

Advisory text summarizes county-level public records and is not a replacement for your utility's current Consumer Confidence Report or direct local notices.

Contaminants & Resources

Key issues flagged in Comanche County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Chlorophyll-a (algae indicator)

    Impairment cause per EPA Clean Water Act §303(d) assessment

  • 2

    High turbidity

    Impairment cause per EPA Clean Water Act §303(d) assessment

  • 3

    Mercury

    Impairment cause per EPA Clean Water Act §303(d) assessment

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for Comanche County

EPA How's My Waterway

Interactive watershed health data for Comanche County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Comanche County

Consumer Confidence Reports (OK)

Annual water quality reports from utilities in Oklahoma

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

100.0%

3 of 3 assessed

High concern

Top Impairment Causes

  • 1

    CHLOROPHYLL-A

  • 2

    TURBIDITY

  • 3

    MERCURY

Source: EPA ATTAINS · Reporting cycle 2022

Impairment is determined under the Clean Water Act §303(d): a water body is impaired when it fails to meet state-defined quality standards for designated uses (drinking, recreation, aquatic life). Assessment coverage varies by state; counties without assessed water bodies are not shown.

Past 5 years

Water Quality Monitoring

Monitoring Sites

19

Active in the past 5 years

Measurements Recorded

8.9K

8,880 total readings

Most Measured

  • Physical
  • Biological, Algae, Phytoplankton
  • Nutrient

Categories measured most frequently

Data from the EPA Water Quality Portal (WQP), aggregating monitoring records from federal, state, and tribal sources. Each measurement represents a single sample analyzed for a specific characteristic (e.g., E. coli, pH, dissolved oxygen, nitrogen).

Live USGS Streamgage

River & Stream Conditions

Current Discharge

3.86cfs

May 14, 6:45 PM UTC

vs Long-Term Average

20%

Well below typical

Primary Streamgage

Little Washita River near Cement, OK

USGS site
07327447
Drainage area
62.3 sq mi
Long-term mean
19.4 cfs

One representative streamgage (the one with the largest drainage area in the county). Many counties have multiple gauges; this view summarizes the primary one. The long-term mean is the full-record annual average; the percent-of-typical value compares the latest reading against that average.

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Water Cost Estimate

3

3 people  ·  ~225 gal/day

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Comanche County:F — Failing

High violation count or severe watershed conditions.

Estimates use the national average residential water rate ($0.0068/gal, EPA/AWWA 2023) and EPA WaterSense per-person consumption baseline (75 gal/person/day). Actual bills vary by utility, usage tier, and local infrastructure fees. For informational purposes only.

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Frequently Asked Questions

What is the water quality in Comanche County, Oklahoma?
Comanche County, Oklahoma has a drinking-water quality grade of F with a score of 29.2/100, based on EPA SDWIS compliance data. The county has 97 health-based drinking water violations over the past 5 years. Watershed health, monitoring records, and streamflow snapshots are reported separately on this page.
Are there any water violations in Comanche County?
Comanche County has 97 health-based drinking water violations recorded by the EPA over the past 5 years. Health-based violations indicate instances where contaminant levels exceeded EPA Maximum Contaminant Levels (MCLs). Violations may have been resolved — check with your local water utility for current status.
How healthy are the watersheds in Comanche County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 100.0% of Comanche County's 3 assessed water bodies are classified as impaired (3 impaired). The top reported causes are CHLOROPHYLL-A, TURBIDITY, MERCURY. Impairment means the water body fails to meet state quality standards for at least one designated use — drinking water source, recreation, aquatic life, or fish consumption. Note: watershed impairment doesn't always translate to tap-water issues; treatment plants can remove most regulated contaminants.
How much water-quality monitoring happens in Comanche County?
EPA's Water Quality Portal records 8,880 measurements from 19 monitoring sites in Comanche County over the past five years. The most frequently measured characteristic groups are Physical, Biological, Algae, Phytoplankton, Nutrient. Each measurement is a single sample analyzed for one characteristic (E. coli, pH, dissolved oxygen, etc.). High monitoring density means more scientific evidence behind any reported signal — it does not by itself indicate water quality.
What's happening with rivers in Comanche County right now?
Comanche County's primary USGS streamgage on the Little Washita River has a pipeline snapshot of 3.86 cubic feet per second — 20% of the long-term mean of 19.4 cfs. This is well below typical — often a signal of drought stress on source water. For the latest gauge feed, visit waterdata.usgs.gov.
How does Comanche County water compare to the Oklahoma average?
Comanche County's SDWIS water quality score of 29.2/100 is higher than the Oklahoma state average of 15.8. The average water quality grade across Oklahoma is F, based on data from 77 counties with available SDWIS data.
Is tap water safe to drink in Comanche County?
Based on EPA SDWIS data, Comanche County has a water quality grade of F (29.2/100). This indicates below-average compliance with significant violations. Residents may want to consider home water filtration or independent testing. The grade speaks to the public water system, not the watershed — for watershed-level concerns, see the Watershed Health zone. For the most up-to-date information, contact your local water utility or review your Consumer Confidence Report (CCR).
Why does Comanche County have so many water violations?
Comanche County has 97 health-based drinking water violations on record from the EPA SDWIS database. A higher violation count can result from aging infrastructure, underfunded water utilities, agricultural runoff contamination, or industrial pollution. Counties with more water systems may also see more violations simply due to scale. Residents concerned about water quality should consider independent water testing and home filtration systems.
How does Comanche County rank for water quality in Oklahoma?
Comanche County ranks #16 out of 77 counties in Oklahoma by SDWIS water quality score (1 = best). With a score of 29.2/100, it falls in the top third of counties statewide. The ranking reflects EPA SDWIS compliance only — not watershed impairment, monitoring density, or streamflow, which are tracked separately on this page.

Counties with Similar Water Quality

Garfield County

Oklahoma

F

29.2

Water score

Ottawa County

Oklahoma

F

29.2

Water score

Logan County

Oklahoma

F

28.9

Water score

Data Sources

Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. Scores reflect compliance history and health-based violation counts.

Watershed health and impaired-waterway data from the EPA ATTAINS Clean Water Act §303(d) assessments, state-reported and EPA-finalized.

Water-quality monitoring counts from the EPA Water Quality Portal (WQP), federated USGS, EPA, and state agency sampling records over a rolling 5-year window.

Live streamflow from the USGS National Water Information System (NWIS), continuous discharge measurements from the largest-drainage gauge in each county, compared against the full-record long-term annual mean.

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.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

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