01The verdict: is Oquawka water safe?
Based on EPA testing data, Oquawka's tap water is generally safe to drink. The water system earned a grade of A+ (95.4/100), meeting federal drinking water standards across key contaminant categories. The city's 1 water system serves approximately 1,125 residents using groundwater (wells).
Nothing over a legal limit
Every contaminant measured in Oquawka's water is within its EPA limit, and no violations are unresolved.
See the testing ↓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 ↓3 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 ↓Oquawka's drinking water received a grade of A+ (95.4 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 1,125 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 6 violations on record, including 0 health-based violations. All violations have been resolved.
Oquawka ranks #11 out of 882 cities in Illinois for water quality, placing it one of the best in the state. Oquawka 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, Oquawka may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in Oquawka's water
Every contaminant flagged in Oquawka, 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 Illinois
Cities ranked by compounds detected Cu Copper in Illinois
Cities ranked by 90th-percentile copper
03Oquawka'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 6 violations on record, including 0 health-based violations. All violations have been resolved.
8 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 10 ppb since 1993. Latest reading: 0 ppb (2024) — 0% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Oquawka's water comes from
Oquawka's drinking water is drawn from underground aquifers through wells.
Groundwater
Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.
Local treatment
Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.
1 system
1 water system, operated under local government ownership.
1,125 people
Residents served across Oquawka's service area.
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 1,125 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| OQUAWKA | IL0710300 | 1,125 | Groundwater |
Water bodies near Oquawka
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Oquawka'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.
Flood & storm history
9 federal disaster declarations on record for Henderson County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
06How Oquawka compares
Scores for nearby Illinois cities on one line, with the average marked.
dashed line = Illinois average (55/100)
Oquawka scores 95.4/100 — above the Illinois average of 55/100. It outscores 10 of 10 nearby cities. Full Illinois rankings →
35.2 / 100DAurora, IL
45.5 / 100FJoliet, IL
38.5 / 100BNaperville, IL
81.2 / 100FRockford, IL
38.4 / 100FKankakee, IL
42.6 / 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 Oquawka's water — not generic advice.
A basic carbon filter still helps
Oquawka'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 Oquawka 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 Oquawka, IL tap water safe to drink?
Oquawka's water quality earned a grade of A+ (95.4/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #11 out of 882 cities tested in Illinois.
What contaminants are in Oquawka's water?
Lead was measured at 0.0 ppb (90th percentile). 6 violations are on record.
How is Oquawka'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 Oquawka?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Oquawka's water come from?
Oquawka's water is sourced from Groundwater. The city has 1 water system serving approximately 1,125 residents.
Is Oquawka's groundwater at risk of contamination?
Oquawka 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 6 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 Oquawka's water compare to other cities?
Oquawka ranks #11 out of 882 cities in Illinois (better than 99% of state cities) and #319 out of 15382 cities nationally (98th percentile). The grade of A+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Oquawka's small water system affect quality?
Oquawka's system serves approximately 1,125 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 6 violations on record.