Is Sentinel, OK Tap Water Safe to Drink?
Graded A, with 1 unresolved violation on record. See what was cited — and what it means for your tap. What to do next ↓
93.4/100
waterverge.com Sentinel, OK — Water Quality Report
Sentinel's drinking water received a grade of A (93.4 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 859 residents using purchased ground water.
Lead levels were measured at 0.6 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 11 violations on record, including 1 health-based violation. 1 remains unresolved.
What to know about Sentinel's water
Sentinel ranks #6 out of 358 cities in Oklahoma for water quality, placing it one of the best in the state.
Sentinel purchases its water from a regional wholesaler, meaning quality depends on both the supplier's treatment and the local distribution system's condition.
As a small community water system, Sentinel may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Sentinel, OK water safe to drink?
Sentinel's tap water meets most EPA standards but has areas that warrant attention. With a grade of A (93.4/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 859 residents using groundwater (wells).
Recent water quality updates for Sentinel
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Sentinel's water quality assessment. Grade: A (93.4/100).
Contaminants: Revised Total Coliform Rule.
Contaminants: Chlorine.
Contaminants: Coliform (TCR).
Federal disaster declaration (FEMA DR-3219). Hurricane event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-778). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Sentinel's water supply.
Well within EPA limits.
Violation history
Sentinel's water system has 11 total violations on record, including 1 health-based violation. 1 remain unresolved. 2 violations were issued in the last 5 years.
Flood & environmental risk
Washita County has experienced 3 federally declared disasters since 1982. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does Sentinel's water come from?
Sentinel's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 859 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Sentinel residents can do
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.
Sentinel'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.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Drought conditions
D3 — extreme droughtWashita 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.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Washita County has experienced 3 federally declared disasters since 1982. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 0.6 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Sentinel compares by contaminant
Explore where Sentinel ranks among all Oklahoma cities for specific contaminants.
Water source & infrastructure
Where Sentinel's water comes from
Sentinel purchases its water supply from a regional wholesale provider rather than treating raw water directly.
Water quality depends on both the wholesaler's treatment standards and the condition of Sentinel's local distribution pipes and storage facilities.
Purchased water systems are common in suburban areas and smaller communities that lack the infrastructure for independent treatment.
The system is operated by local government ownership and serves approximately 859 people through 1 water system.
Water systems serving Sentinel
| System Name | PWSID | Population | Source |
|---|---|---|---|
| SENTINEL PWS | OK3007505 | 859 | GWP |
How Sentinel compares
Full Oklahoma rankings →Sentinel's score of 93.4/100 is above the average of 45/100 among major Oklahoma cities. It outscores 10 of 10 nearby cities.
Nearby cities
View Oklahoma rankings →About Sentinel, OK
Wikipedia →Sentinel is a town in Washita County, in the U.S. state of Oklahoma. As of the 2020 census, Sentinel had a population of 763. Towns near Sentinel are Rocky, Cordell, Canute, and Burnsflat.
Learn more about your water
Guides and resources related to Sentinel's water quality findings.
Explore water quality across Washita
Frequently asked questions
Is Sentinel, OK tap water safe to drink?
Sentinel's water quality earned a grade of A (93.4/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #6 out of 358 cities tested in Oklahoma.
What contaminants are in Sentinel's water?
Lead was measured at 0.6 ppb (90th percentile). 11 violations are on record.
How is Sentinel'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 Sentinel?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Sentinel's water come from?
Sentinel's water is sourced from Purchased ground water. The city has 1 water system serving approximately 859 residents.
What health violations has Sentinel's water system had?
Sentinel has 1 health-based violation on record. The most recent violation was recorded in August 2021. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 1 violation remains unresolved.
Is Sentinel's groundwater at risk of contamination?
Sentinel 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 11 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 Sentinel's water compare to other cities?
Sentinel ranks #6 out of 358 cities in Oklahoma (better than 98% of state cities) and #862 out of 15744 cities nationally (95th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Sentinel's small water system affect quality?
Sentinel's system serves approximately 859 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 11 violations on record.