WaterVerge

Is Sulphur, OK Tap Water Safe to Drink?

Graded A-, with 6 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓

11K residents served 3 water systems PWSID: OK2005001
Overall Score
86 / 100
Violations
6 active
Last Updated
May 2026
Source
Groundwater
#38 of 358 in Oklahoma Top 32% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
A-GRADE
Water Quality Grade
86/100
waterverge.com
A- 86/100

Sulphur, OK — Water Quality Report

Sulphur's drinking water received a grade of A- (86 out of 100), indicating good water quality. The city's 3 water systems serve approximately 10,989 residents using groundwater.

Lead levels were measured at 1.3 ppb (90th percentile), well within EPA limits. PFAS testing under UCMR 5 found no detectable forever chemicals.

The system has 17 violations on record, including 2 health-based violations. 6 remain unresolved.

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

What to know about Sulphur's water

Sulphur ranks #38 out of 358 cities in Oklahoma for water quality, placing it above average in the state.

Sulphur 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.

Quality Breakdown

Water quality score

See methodology →
86 out of 100 Grade A-
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
38/45
B
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 1.3 ppb (90th percentile).
Contaminants
18/20
A
No PFAS compounds detected.
Compliance
5/10
D
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Sulphur, OK water safe to drink?

Concerns Identified

Sulphur's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (86/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 3 water systems serve approximately 10,989 residents using groundwater (wells).

6
Active Violations
1.3 ppb
Lead (90th %ile)
None
PFAS Detected
3 events
Disaster History

Recent water quality updates for Sulphur

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

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Sulphur's water quality assessment. Grade: A- (86/100).

Violation
2 drinking water violations recorded

1 health-based. Contaminants: LEAD AND COPPER RULE REVISIONS.

Violation
1 drinking water violation recorded

Contaminants: Consumer Confidence Rule.

Violation
1 drinking water violation recorded

Contaminants: Lead and Copper Rule.

Disaster
HURRICANE KATRINA EVACUATION

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

Disaster
SEVERE STORMS & FLOODING

Federal disaster declaration (FEMA DR-794). Flood event — may have impacted local water infrastructure.

Key contaminant findings

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

Lead Within Limits
Detected: 1.3 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

Violation history

Sulphur's water system has 17 total violations on record, including 2 health-based violations. 6 remain unresolved. 2 violations were issued in the last 5 years.

TTRPTOtherMRMCL
Most recent violations:
Oct 2024 LEAD AND COPPER RULE REVISIONS Open
Oct 2024 LEAD AND COPPER RULE REVISIONS Open
Jul 2014 Consumer Confidence Rule Open
Oct 2009 Lead and Copper Rule Open
Jan 2008 Nitrate-Nitrite Resolved

Flood & environmental risk

Murray County has experienced 3 federally declared disasters since 1973. 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 01S-03E-01 Abb 1 Antelope Spring At Sulphur, Rock Creek At Sulphur, Mill Creek Near Sulphur, Mill Creek Near Mill Creek, Mill Cr At Mouth Of 3Mile Cr Near Mill Cr.

HURRICANE KATRINA EVACUATION
Hurricane FEMA DR-3219
SEVERE STORMS & FLOODING
Flood FEMA DR-794
SEVERE STORMS & FLOODING
Flood FEMA DR-409

Where does Sulphur's water come from?

Sulphur's drinking water comes from groundwater (wells), supplied by 3 water systems serving approximately 10,989 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include 01S-03E-01 Abb 1 Antelope Spring At Sulphur (spring), Rock Creek At Sulphur (river), Mill Creek Near Sulphur (river), Mill Creek Near Mill Creek (river), Mill Cr At Mouth Of 3Mile Cr Near Mill Cr (river).

What Sulphur residents can do

Install a water filter

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

Sulphur'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
1.3 ppb
EPA Action Level: 15 ppb · 9% of limit
Safe Level
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
0
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

17
Total violations
2
Health-based
6
Active / unresolved
Oct 2024
Most recent violation
Compliance Record

Violations & advisories

17 Total
6 Active
2 Health-based
11 Resolved
Violations by category
Total Coliform Rule
8
Lead and Copper Rule Revisions
2
Nitrate Rule
2
Consumer Confidence Rule
1
Lead and Copper Rule
1
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
Jul 2014 Active
Consumer Confidence Rule
Other Violation 0
Oct 2009 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Active
Compliance Violation
Monitoring 0
Active
Compliance Violation
Monitoring 0
Jan 2008 Resolved
Nitrate-Nitrite
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2008
Jan 2007 Resolved
Nitrate-Nitrite
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2007
Jan 2005 Resolved
2,4-D
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2007
Jul 2003 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Jul 2003
Jun 2003 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Jun 2003
May 2003 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved May 2003
Apr 2003 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Apr 2003
Aug 1998 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Aug 1998
Jul 1998 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Jul 1998
Jun 1997 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Jun 1997
Jul 1993 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Jul 1993
Environmental Risk

Drought conditions

D1 — moderate drought

Murray County is currently in D1 (moderate 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.

12.5%
Months in D2+ (last 30y)
4
Weeks at D2+ (last 5y)

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

Environmental Risk

Flood & disaster history

3
Declared disasters
Sep 2005
Most recent
Flood
Most common type

Murray County has experienced 3 federally declared disasters since 1973. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3219
Jul 1987
SEVERE STORMS & FLOODING
Flood FEMA #794
Dec 1973
SEVERE STORMS & FLOODING
Flood FEMA #409

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 1.3 15 ppb Inorganic Safe
11Cl-PF3OUdS ND HI µg/L PFAS Not Detected
4:2 FTS ND HI µg/L PFAS Not Detected
6:2 FTS ND HI µg/L PFAS Not Detected
8:2 FTS ND HI µg/L PFAS Not Detected
9Cl-PF3ONS ND HI µg/L PFAS Not Detected
ADONA ND HI µg/L PFAS Not Detected
HFPO-DA ND 0.01 µg/L PFAS Not Detected
lithium ND HI µg/L PFAS Not Detected
NEtFOSAA ND HI µg/L PFAS Not Detected
NFDHA ND HI µg/L PFAS Not Detected
NMeFOSAA ND HI µg/L PFAS Not Detected
PFBA ND HI µg/L PFAS Not Detected
PFBS ND HI µg/L PFAS Not Detected
PFDA ND HI µg/L PFAS Not Detected
PFDoA ND HI µg/L PFAS Not Detected
PFEESA ND HI µg/L PFAS Not Detected
PFHpA ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA ND HI µg/L PFAS Not Detected
PFHxS ND HI µg/L PFAS Not Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA ND 0.004 µg/L PFAS Not Detected
PFOS ND 0.004 µg/L PFAS Not Detected
PFPeA ND HI µg/L PFAS Not Detected
PFPeS ND HI µg/L PFAS Not Detected
PFTA ND HI µg/L PFAS Not Detected
PFTrDA ND HI µg/L PFAS Not Detected
PFUnA ND HI µg/L PFAS Not Detected
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has increased by 1.3 ppb from 1992 (0.0 ppb) to 2025 (1.3 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Local Government
Population Served
10,989
Water Systems
3
Source breakdown
Groundwater
2
Purchased Groundwater
1
Water Source

Where Sulphur's water comes from

Groundwater

Sulphur'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 10,989 people through 3 water systems.

Local Hydrology

Water bodies near Sulphur

Sulphur is located near 5 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.

01S-03E-01 Abb 1 Antelope Spring At Sulphur
spring
Rock Creek At Sulphur
river
Mill Creek Near Sulphur
river
Mill Creek Near Mill Creek
river
Mill Cr At Mouth Of 3Mile Cr Near Mill Cr
river
Infrastructure

Water systems serving Sulphur

System Name PWSID Population Source
SULPHUR OK2005001 4,929 GW
MURRAY CO RWD # 1 OK2005012 4,800 GW
BUCKHORN RWD #2 OK3005002 1,260 GWP
Regional Comparison

How Sulphur compares

Full Oklahoma rankings →

Sulphur's score of 86/100 is above the average of 45/100 among major Oklahoma cities. It outscores 10 of 10 nearby cities.

Sulphur (this city)
86
Tulsa
48.5
Norman
38.4
Lawton
44.4
Oklahoma avg
45
City Profile

About Sulphur, OK

Wikipedia →

Sulphur is a city in and the county seat of Murray County, Oklahoma, United States. The population was 5,065 at the 2020 census. The area around Sulphur has been noted for its mineral springs since well before the city was founded late in the 19th century. The city received its name from the presence of sulfur in the water.

Economic Profile
$55,951
Median Income
$137,289
Median Home Value
$869/mo
Median Rent
0%
Unemployment
Community
38.8
Median Age
283
People / sq mi
17.3%
College Educated
65.4%
Homeownership
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Frequently asked questions

Is Sulphur, OK tap water safe to drink?

Sulphur's water quality earned a grade of A- (86/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #38 out of 358 cities tested in Oklahoma.

What contaminants are in Sulphur's water?

Lead was measured at 1.3 ppb (90th percentile). No PFAS compounds were detected. 17 violations are on record.

How is Sulphur'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 Sulphur?

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

Where does Sulphur's water come from?

Sulphur's water is sourced from Groundwater. The city has 3 water systems serving approximately 10,989 residents.

What health violations has Sulphur's water system had?

Sulphur has 2 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. 6 violations remain unresolved.

Is Sulphur's groundwater at risk of contamination?

Sulphur 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 17 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 Sulphur's water compare to other cities?

Sulphur ranks #38 out of 358 cities in Oklahoma (better than 89% of state cities) and #4963 out of 15744 cities nationally (69th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.