01The verdict: is Union City water safe?
Union City'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 1 water system serves approximately 618 residents using gup.
5 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 ↓22 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 ↓Union City's drinking water received a grade of D (49 out of 100), indicating poor water quality. The city's 1 water system serves approximately 618 residents using gup.
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 39 violations on record, including 24 health-based violations. 5 remain unresolved.
Union City ranks #246 out of 357 cities in Oklahoma for water quality, placing it below average in the state. As a small community water system, Union City may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities. The system has seen 22 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
02What's in Union City's water
Every contaminant flagged in Union City, 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
03Union City'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 39 violations on record, including 24 health-based violations. 5 remain unresolved.
7 of the last ten years were clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.
▼ Down 6 ppb since 1993. Latest reading: 0 ppb (2024) — 0% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Union City's water comes from
Union City's water comes from groundwater under the direct influence of surface water, a designation that requires the same treatment rigor as surface water systems.
GUP
Source details for this system are limited in EPA records.
Local treatment
Treatment is regulated under the Safe Drinking Water Act.
1 system
1 water system, operated under local government ownership.
618 people
Residents served across Union City's service area.
This source type is vulnerable to both surface contamination pathways and naturally occurring underground contaminants. The system is operated by local government ownership and serves approximately 618 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| UNION CITY | OK3000909 | 618 | GUP |
05Pressure on Union City'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 0 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
5 federal disaster declarations on record for Canadian County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
Drought
Canadian County is in D2 (severe drought) per the U.S. Drought Monitor (week of Jul 2026). Drought can raise disinfection-byproduct levels and taste/odor issues as utilities draw from lower reservoirs.
06How Union City compares
Scores for nearby Oklahoma cities on one line, with the average marked.
dashed line = Oklahoma average (45/100)
Union City 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 Union City's water — not generic advice.
A basic carbon filter still helps
Union City'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 Union City 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 Union City, OK tap water safe to drink?
Union City's water quality earned a grade of D (49/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #246 out of 357 cities tested in Oklahoma.
What contaminants are in Union City's water?
Lead was measured at 0.0 ppb (90th percentile). 39 violations are on record.
How is Union City'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 Union City?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Union City's water come from?
Union City's water is sourced from GUP. The city has 1 water system serving approximately 618 residents.
What health violations has Union City's water system had?
Union City has 24 health-based violations on record. The most recent violation was recorded in January 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 5 violations remain unresolved.
How does Union City's water compare to other cities?
Union City ranks #246 out of 357 cities in Oklahoma (better than 31% of state cities) and #13128 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.
Does Union City's small water system affect quality?
Union City's system serves approximately 618 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 39 violations on record.