WaterVerge

Is Ninnekah, OK Tap Water Safe to Drink?

Graded B+, with 4 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓

2K residents served 1 water system PWSID: OK2002633
Overall Score
84.7 / 100
Violations
4 active
Last Updated
May 2026
Source
Groundwater
#51 of 358 in Oklahoma Top 37% nationally
Local Government
Moderate data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
B+GRADE
Water Quality Grade
84.7/100
waterverge.com
B+ 84.7/100

Ninnekah, OK — Water Quality Report

Ninnekah's drinking water received a grade of B+ (84.7 out of 100), indicating good water quality. The city's 1 water system serves approximately 2,425 residents using groundwater.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.

The system has 21 violations on record, including 9 health-based violations. 4 remain unresolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Ninnekah's water

Ninnekah ranks #51 out of 358 cities in Oklahoma for water quality, placing it above average in the state.

Ninnekah relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.

As a small community water system, Ninnekah may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.

Quality Breakdown

Water quality score

See methodology →
84.7 out of 100 Grade B+
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
34.7/45
B
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.0 ppb (90th percentile).
Contaminants
17/20
B
PFAS + legacy contaminant analysis.
Compliance
8/10
B
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Ninnekah, OK water safe to drink?

Concerns Identified

Ninnekah's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (84.7/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 2,425 residents using groundwater (wells).

4
Active Violations
0.0 ppb
Lead (90th %ile)
5 events
Disaster History

Recent water quality updates for Ninnekah

A timeline of significant water quality events, violations, and data updates.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Ninnekah's water quality assessment. Grade: B+ (84.7/100).

Violation
3 drinking water violations recorded

1 health-based. Contaminants: LEAD AND COPPER RULE REVISIONS, Lead and Copper Rule.

Violation
2 drinking water violations recorded

Contaminants: Revised Total Coliform Rule, Chlorine.

Violation
1 drinking water violation recorded

Contaminants: Arsenic.

Disaster
SEVERE STORMS AND FLOODING

Federal disaster declaration (FEMA DR-4274). Flood event — may have impacted local water infrastructure.

Disaster
HURRICANE KATRINA EVACUATION

Federal disaster declaration (FEMA DR-3219). Hurricane event — may have impacted local water infrastructure.

Key contaminant findings

Based on the most recent EPA sampling data for Ninnekah's water supply.

Lead Within Limits
Detected: 0.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

Violation history

Ninnekah's water system has 21 total violations on record, including 9 health-based violations. 4 remain unresolved. 5 violations were issued in the last 5 years.

TTRPTMRMONMCL
Most recent violations:
Oct 2024 LEAD AND COPPER RULE REVISIONS Open
Oct 2024 LEAD AND COPPER RULE REVISIONS Open
Oct 2024 Lead and Copper Rule Open
Jan 2024 Revised Total Coliform Rule Resolved
Jan 2024 Chlorine Resolved

Flood & environmental risk

Grady County has experienced 5 federally declared disasters since 1983. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Little Washita River East Of Ninnekah, Washita River At Alex.

SEVERE STORMS AND FLOODING
Flood FEMA DR-4274
HURRICANE KATRINA EVACUATION
Hurricane FEMA DR-3219
SEVERE STORMS & FLOODING
Flood FEMA DR-794

Where does Ninnekah's water come from?

Ninnekah's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 2,425 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Little Washita River East Of Ninnekah (river), Washita River At Alex (river).

What Ninnekah residents can do

Install a water filter

Recommended: NSF-certified water filter. This addresses the specific contaminants found in Ninnekah's water.

Request your utility's CCR

Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.

Monitor alerts during storms

Ninnekah's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.

Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
0.0 ppb
EPA Action Level: 15 ppb · 0% of limit
Safe Level
Compliance Record

Violation summary

21
Total violations
9
Health-based
4
Active / unresolved
Oct 2024
Most recent violation
Compliance Record

Violations & advisories

21 Total
4 Active
9 Health-based
17 Resolved
Violations by category
Arsenic Rule
8
Radionuclides and Revised Rad Rule
4
Lead and Copper Rule Revisions
2
Lead and Copper Rule
2
Total Coliform Rule
2
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Treatment Technique
Health-Based Health 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Reporting
Reporting 0
Oct 2024 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Active
Compliance Violation
Monitoring 0
Jan 2024 Resolved
Revised Total Coliform Rule
Monitoring
Monitoring Resolved Jan 2024
Jan 2024 Resolved
Chlorine
Monitoring & Reporting
Monitoring & Reporting Resolved Mar 2024
Jan 2017 Resolved
Arsenic
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2019
Jan 2014 Resolved
Gross Beta Particle Activity
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2019
Jan 2014 Resolved
Gross Alpha, Excl. Radon and U
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2019
Jan 2014 Resolved
Combined Uranium
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2019
Jan 2014 Resolved
Combined Radium (-226 and -228)
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2019
Jul 2009 Resolved
Arsenic
Max Contaminant Level
Health-Based Health Resolved Sep 2009
Apr 2009 Resolved
Arsenic
Max Contaminant Level
Health-Based Health Resolved Jun 2009
Jan 2009 Resolved
Arsenic
Max Contaminant Level
Health-Based Health Resolved Mar 2009
Oct 2008 Resolved
Arsenic
Max Contaminant Level
Health-Based Health Resolved Dec 2008
Jul 2008 Resolved
Arsenic
Max Contaminant Level
Health-Based Health Resolved Sep 2008
Apr 2008 Resolved
Arsenic
Max Contaminant Level
Health-Based Health Resolved Jun 2008
Oct 2007 Resolved
Arsenic
Max Contaminant Level
Health-Based Health Resolved Dec 2007
Dec 1993 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 1993
Jun 1993 Resolved
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting Resolved Oct 1994
Showing 20 of 21 violations
Industrial pollution

Top industrial polluters within 10 miles of Ninnekah

Industrial polluters nearby

Reported releases to surface water by facilities near Ninnekah, ranked by pounds discharged annually.

FacilityTop chemicalTo surface water (lbs/yr)Distance
DCP MIDSTREAM - CHITWOOD
Natural Gas Processing · PHILLIPS 66 CO
ALEX, OK73002
9.9 mi
BAITY SCREW MACHINE PRODUCTS INC
Fabricated Metals · NA
CHICKASHA, OK73018
6.3 mi
LIQUIDPOWER SPECIALTY PRODUCTS INC.
Chemicals · BERKSHIRE HATHAWAY INC
CHICKASHA, OK73018
6.8 mi
CHICKASHA BATCH PLANT
Nonmetallic Mineral Product · DOLESE BROS CO
CHICKASHA, OK73018
3.8 mi
COOLING TOWER COMPOSITES & FABRICATION
Plastics and Rubber · NA
CHICKASHA, OK73018
6.7 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Environmental Risk

Drought conditions

D3 — extreme drought

Grady County is currently in D3 (extreme drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.

14
Weeks at D2+ (current streak)
12.5%
Months in D2+ (last 30y)
14
Weeks at D2+ (last 5y)

Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.

Environmental Risk

Flood & disaster history

5
Declared disasters
Jul 2016
Most recent
Flood
Most common type

Grady County has experienced 5 federally declared disasters since 1983. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Jul 2016
SEVERE STORMS AND FLOODING
Flood FEMA #4274
Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3219
Jul 1987
SEVERE STORMS & FLOODING
Flood FEMA #794
Oct 1986
SEVERE STORMS & FLOODING
Flood FEMA #778
Oct 1983
SEVERE STORMS & FLOODING
Flood FEMA #693

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 15 ppb Inorganic Safe
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 0.0 ppb from 1994 (0.0 ppb) to 2021 (0.0 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Local Government
Population Served
2,425
Water Systems
1
Water Source

Where Ninnekah's water comes from

Groundwater

Ninnekah's drinking water is drawn from underground aquifers through wells.

Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.

Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.

The system is operated by local government ownership and serves approximately 2,425 people through 1 water system.

Local Hydrology

Water bodies near Ninnekah

Ninnekah is located near 2 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.

Little Washita River East Of Ninnekah
river
Washita River At Alex
river
Infrastructure

Water systems serving Ninnekah

System Name PWSID Population Source
GRADY CO RWD #7 (NINNEKAH) OK2002633 2,425 GW
Regional Comparison

How Ninnekah compares

Full Oklahoma rankings →

Ninnekah's score of 84.7/100 is above the average of 45/100 among major Oklahoma cities. It outscores 10 of 10 nearby cities.

Ninnekah (this city)
84.7
Tulsa
48.5
Norman
38.4
Lawton
44.4
Oklahoma avg
45
City Profile

About Ninnekah, OK

Economic Profile
$66,944
Median Income
$163,811
Median Home Value
$850/mo
Median Rent
2.9%
Unemployment
Community
42.8
Median Age
38
People / sq mi
13.3%
College Educated
84.1%
Homeownership
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Frequently asked questions

Is Ninnekah, OK tap water safe to drink?

Ninnekah's water quality earned a grade of B+ (84.7/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #51 out of 358 cities tested in Oklahoma.

What contaminants are in Ninnekah's water?

Lead was measured at 0.0 ppb (90th percentile). 21 violations are on record.

How is Ninnekah's water quality grade calculated?

The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.

Do I need a water filter in Ninnekah?

Based on current data, basic filtration should suffice for additional peace of mind.

Where does Ninnekah's water come from?

Ninnekah's water is sourced from Groundwater. The city has 1 water system serving approximately 2,425 residents.

What health violations has Ninnekah's water system had?

Ninnekah has 9 health-based violations on record. The most recent violation was recorded in October 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 4 violations remain unresolved.

Is Ninnekah's groundwater at risk of contamination?

Ninnekah uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 21 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.

How does Ninnekah's water compare to other cities?

Ninnekah ranks #51 out of 358 cities in Oklahoma (better than 86% of state cities) and #5734 out of 15744 cities nationally (64th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.

Does Ninnekah's small water system affect quality?

Ninnekah's system serves approximately 2,425 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 21 violations on record.