01The verdict: is Locust Grove water safe?
Locust Grove's drinking water has significant quality concerns based on EPA testing data. With a grade of D (49/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 4 water systems serve approximately 5,031 residents using surface water (rivers, lakes, or reservoirs).
27 unresolved violations on record
EPA records show open compliance items for this system. Most are administrative, but unresolved items are worth watching.
See what was cited ↓Lead is well under the limit
90th-percentile lead is 0.0 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.
See the trend ↓148 violations in the last five years
Recent compliance history is the best predictor of future problems — the year-by-year record is below.
See the record ↓Locust Grove's drinking water received a grade of D (49 out of 100), indicating poor water quality. The city's 4 water systems serve approximately 5,031 residents using surface water.
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 493 violations on record, including 103 health-based violations. 27 remain unresolved.
Locust Grove ranks #227 out of 357 cities in Oklahoma for water quality, placing it below average in the state. The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection. The system has seen 148 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
02What's in Locust Grove's water
Every contaminant flagged in Locust Grove, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
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. | 0.0 | 15 | ppb | Inorganic | Safe |
Cities ranked by 90th-percentile lead PF PFAS in Oklahoma
Cities ranked by compounds detected Cu Copper in Oklahoma
Cities ranked by 90th-percentile copper
03Locust Grove's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 493 violations on record, including 103 health-based violations. 27 remain unresolved.
1 of the last ten years was clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.
▼ Down 0 ppb since 1993. Latest reading: 0 ppb (2025) — 0% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Locust Grove's water comes from
Locust Grove's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface Water
Rivers, lakes, or reservoirs — more exposed to runoff, agriculture, and seasonal swings than groundwater.
Local treatment
Multi-barrier treatment: coagulation, sedimentation, filtration, and disinfection to meet EPA standards.
4 systems
4 water systems, operated under local government ownership.
5,031 people
Residents served across Locust Grove's service area.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards. These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge. The system is operated by local government ownership and serves approximately 5,031 people through 4 water systems.
| System name | PWSID | Population | Source |
|---|---|---|---|
| MAYES CO RWD # 9 | OK1021678 | 2,578 | Surface Water |
| LOCUST GROVE | OK1021668 | 1,600 | Surface Water |
| MAYES CO RWD # 7 | OK3004627 | 538 | Purchased Surface Water |
| CEDAR CREST COUNTRY CLUB | OK3004636 | 315 | Purchased Surface Water |
Water bodies near Locust Grove
As a surface-water system, these water bodies may directly influence Locust Grove's drinking water supply.
05Pressure on Locust Grove's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Industrial discharge
5 facilities within 10 miles reported 2,268k lb released to surface water in the latest EPA Toxics Release Inventory. Proximity doesn't equal tap contamination — treatment and hydrology decide — but it's pressure on the watershed.
Flood & storm history
4 federal disaster declarations on record for Mayes County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
06How Locust Grove compares
Scores for nearby Oklahoma cities on one line, with the average marked.
dashed line = Oklahoma average (45/100)
Locust Grove scores 49/100 — on par with the Oklahoma average of 45/100. It outscores 9 of 10 nearby cities. Full Oklahoma rankings →
38.6 / 100DTulsa, OK
48.5 / 100FBroken Arrow, OK
43.9 / 100FNorman, OK
38.4 / 100FLawton, OK
44.4 / 100FEdmond, OK
34.9 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
07What to do at home
Steps matched to what testing actually found in Locust Grove's water — not generic advice.
A basic carbon filter still helps
Locust Grove's water meets federal standards, but a simple carbon filter improves taste and adds a margin of safety against short-term issues.
Compare tested filters →Read your utility's annual report
Every utility must publish a yearly Consumer Confidence Report with its own testing results. It pairs well with the independent data on this page.
How to read a CCR →Watch for Locust Grove alerts
This area has a history of flood declarations — after severe weather, watch for boil-water advisories from the utility, and check the live alerts on this page.
All water alerts →Frequently asked questions
Is Locust Grove, OK tap water safe to drink?
Locust Grove's water quality earned a grade of D (49/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #227 out of 357 cities tested in Oklahoma.
What contaminants are in Locust Grove's water?
Lead was measured at 0.0 ppb (90th percentile). 493 violations are on record.
How is Locust Grove'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 Locust Grove?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Locust Grove's water come from?
Locust Grove's water is sourced from Surface water. The city has 4 water systems serving approximately 5,031 residents.
What health violations has Locust Grove's water system had?
Locust Grove has 103 health-based violations on record. The most recent violation was recorded in November 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 27 violations remain unresolved.
How does Locust Grove's water compare to other cities?
Locust Grove ranks #227 out of 357 cities in Oklahoma (better than 36% of state cities) and #13058 out of 15382 cities nationally (15th percentile). The grade of D reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.