01The verdict: is Oblong water safe?
Oblong's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (84.5/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 2,321 residents using groundwater (wells).
3 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 3.6 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.
See the trend ↓A flood-prone service area
3 federal disaster declarations on record. After severe weather, watch for boil-water advisories.
See the risk factors ↓Oblong's drinking water received a grade of B+ (84.5 out of 100), indicating good water quality. The city's 1 water system serves approximately 2,321 residents using purchased ground water.
Lead levels were measured at 3.6 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 3 violations on record, including 0 health-based violations. 3 remain unresolved.
Oblong ranks #404 out of 882 cities in Illinois for water quality, placing it mid-range in the state. Oblong 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, Oblong may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in Oblong's water
Every contaminant flagged in Oblong, 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. | 3.6 | 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
03Oblong'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 3 violations on record, including 0 health-based violations. 3 remain unresolved.
9 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 7 ppb since 1993. Latest reading: 0 ppb (2025) — 0% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Oblong's water comes from
Oblong purchases its water supply from a regional wholesale provider rather than treating raw water directly.
Purchased Groundwater
Water is bought from a regional wholesaler; quality starts at the supplier's intake and treatment.
Wholesale supplier
Primary treatment happens at the wholesaler; the local utility maintains disinfectant residual in its pipes.
1 system
1 water system, operated under local government ownership.
2,321 people
Residents served across Oblong's service area.
Water quality depends on both the wholesaler's treatment standards and the condition of Oblong'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 2,321 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| OBLONG | IL0330150 | 2,321 | Purchased Groundwater |
Water bodies near Oblong
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Oblong'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
1 facility within 10 miles reported 304k 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
3 federal disaster declarations on record for Crawford County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
06How Oblong compares
Scores for nearby Illinois cities on one line, with the average marked.
dashed line = Illinois average (55/100)
Oblong scores 84.5/100 — 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 Oblong's water — not generic advice.
A basic carbon filter still helps
Oblong'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 →Flush taps & check your service line
Lead leaches from pipes as water sits. Run cold water 30 seconds before drinking (especially mornings), and ask the utility whether your address still has a lead service line.
Lead risks explained →Watch for Oblong 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 Oblong, IL tap water safe to drink?
Oblong's water quality earned a grade of B+ (84.5/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #404 out of 882 cities tested in Illinois.
What contaminants are in Oblong's water?
Lead was measured at 3.6 ppb (90th percentile). 3 violations are on record.
How is Oblong'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 Oblong?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Oblong's water come from?
Oblong's water is sourced from Purchased ground water. The city has 1 water system serving approximately 2,321 residents.
Is Oblong's groundwater at risk of contamination?
Oblong 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 3 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 Oblong's water compare to other cities?
Oblong ranks #404 out of 882 cities in Illinois (better than 54% of state cities) and #5820 out of 15382 cities nationally (62th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Oblong's small water system affect quality?
Oblong's system serves approximately 2,321 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 3 violations on record.