01The verdict: is Prairie Du Rochr water safe?
Prairie Du Rochr's drinking water has significant quality concerns based on EPA testing data. With a grade of B- (73.8/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 759 residents using groundwater (wells).
Copper is over its legal limit
Measured at 1.80 mg/L against the EPA Action Level of 1.3 mg/L. The ledger below shows how far over — and which filter removes it.
See the measurement ↓759 people, 1 system
All figures on this page come from federal EPA compliance and testing data for the systems serving this city.
See the systems ↓2 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 ↓Prairie Du Rochr's drinking water received a grade of B- (73.8 out of 100), indicating fair water quality. The city's 1 water system serves approximately 759 residents using purchased ground water.
Lead levels were measured at 7.0 ppb (90th percentile), which is within EPA limits but above recommended levels. This system has not yet been tested for PFAS under the EPA UCMR 5 program. The system has 6 violations on record, including 1 health-based violation. 5 remain unresolved.
Prairie Du Rochr ranks #688 out of 882 cities in Illinois for water quality, placing it among the lowest-rated in the state. Prairie Du Rochr purchases its water from a regional wholesaler, meaning quality depends on both the supplier's treatment and the local distribution system's condition. While lead levels are within EPA limits, they are above the recommended 5 ppb threshold that health organizations consider ideal. A point-of-use filter adds an extra layer of protection. As a small community water system, Prairie Du Rochr may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in Prairie Du Rochr's water
Every contaminant flagged in Prairie Du Rochr, 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.
Over Limit — EPA Action Level: 1.3 mg/L
Exceeds the EPA action level. Copper leaches from household plumbing — flush taps for 30 seconds before drinking, and consider a certified filter.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. | 7.0 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 1.80 | 1.3 | mg/L | Inorganic | Over Limit |
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
03Prairie Du Rochr'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 1 health-based violation. 5 remain unresolved.
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.
▲ Up 7 ppb since 1993. Latest reading: 7 ppb (2025) — 47% of the action level. Sampled at higher-risk homes (90th percentile).
▲ Up 0.06 mg/L since 1993. The latest reading (1.8 mg/L, 1994) is over the action level. Sampled at higher-risk homes (90th percentile).
04Where Prairie Du Rochr's water comes from
Prairie Du Rochr 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.
759 people
Residents served across Prairie Du Rochr's service area.
Water quality depends on both the wholesaler's treatment standards and the condition of Prairie Du Rochr'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 759 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| PRAIRIE DU ROCHER | IL1570400 | 759 | Purchased Groundwater |
05Pressure on Prairie Du Rochr'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
7 federal disaster declarations on record for Randolph County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
06How Prairie Du Rochr compares
Scores for nearby Illinois cities on one line, with the average marked.
dashed line = Illinois average (55/100)
Prairie Du Rochr scores 73.8/100 — above the Illinois average of 55/100. It outscores 7 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 Prairie Du Rochr's water — not generic advice.
Filter drinking & cooking water
NSF-certified water filter. Lead detected at 7.0 ppb
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 Prairie Du Rochr 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 Prairie Du Rochr, IL tap water safe to drink?
Prairie Du Rochr's water quality earned a grade of B- (73.8/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #688 out of 882 cities tested in Illinois.
What contaminants are in Prairie Du Rochr's water?
Lead was measured at 7.0 ppb (90th percentile). 6 violations are on record.
How is Prairie Du Rochr'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 Prairie Du Rochr?
While lead levels are within EPA limits, a filter adds extra protection. Based on current data, basic filtration should suffice for additional peace of mind.
Where does Prairie Du Rochr's water come from?
Prairie Du Rochr's water is sourced from Purchased ground water. The city has 1 water system serving approximately 759 residents.
What health violations has Prairie Du Rochr's water system had?
Prairie Du Rochr has 1 health-based violation on record. The most recent violation was recorded in July 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 5 violations remain unresolved.
Is Prairie Du Rochr's groundwater at risk of contamination?
Prairie Du Rochr 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 Prairie Du Rochr's water compare to other cities?
Prairie Du Rochr ranks #688 out of 882 cities in Illinois (better than 22% of state cities) and #9890 out of 15382 cities nationally (36th percentile). The grade of B- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Prairie Du Rochr's small water system affect quality?
Prairie Du Rochr's system serves approximately 759 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.