01The verdict: is Rockdale water safe?
Rockdale's drinking water has significant quality concerns based on EPA testing data. With a grade of C- (56.9/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 2,012 residents using groundwater (wells).
Copper is over its legal limit
Measured at 1.36 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 ↓2K 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 ↓Lead is approaching its limit
Measured at 12.8 ppb — 85% of the 15 ppb limit. Within the rules, but with less headroom than you'd want.
See the ledger ↓Rockdale's drinking water received a grade of C- (56.9 out of 100), indicating poor water quality. The city's 1 water system serves approximately 2,012 residents using groundwater.
Lead levels were measured at 12.8 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 62 violations on record, including 36 health-based violations. 16 remain unresolved.
Rockdale ranks #814 out of 882 cities in Illinois for water quality, placing it among the lowest-rated in the state. Rockdale 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. 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, Rockdale may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities. The system has seen 14 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
02What's in Rockdale's water
Every contaminant flagged in Rockdale, 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. | 12.8 | 15 | ppb | Inorganic | Near Limit |
| 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. | 1.36 | 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
03Rockdale'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 62 violations on record, including 36 health-based violations. 16 remain unresolved.
4 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 7.8 ppb since 1993. Latest reading: 2.2 ppb (2025) — 15% of the action level. Sampled at higher-risk homes (90th percentile).
▲ Up 0.01 mg/L since 2023. The latest reading (1.4 mg/L, 2025) is over the action level. Sampled at higher-risk homes (90th percentile).
04Where Rockdale's water comes from
Rockdale'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.
2,012 people
Residents served across Rockdale'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 2,012 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| ROCKDALE | IL1970850 | 2,012 | Groundwater |
Water bodies near Rockdale
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Rockdale'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 560k 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
6 federal disaster declarations on record for Will County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
Superfund proximity
3 National Priorities List sites within 10 miles. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.
06How Rockdale compares
Scores for nearby Illinois cities on one line, with the average marked.
dashed line = Illinois average (55/100)
Rockdale scores 56.9/100 — on par with the Illinois average of 55/100. It outscores 6 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 Rockdale's water — not generic advice.
Filter drinking & cooking water
NSF-certified water filter. Lead detected at 12.8 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 Rockdale 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 Rockdale, IL tap water safe to drink?
Rockdale's water quality earned a grade of C- (56.9/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #814 out of 882 cities tested in Illinois.
What contaminants are in Rockdale's water?
Lead was measured at 12.8 ppb (90th percentile). 62 violations are on record.
How is Rockdale'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 Rockdale?
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 Rockdale's water come from?
Rockdale's water is sourced from Groundwater. The city has 1 water system serving approximately 2,012 residents.
What health violations has Rockdale's water system had?
Rockdale has 36 health-based violations on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 16 violations remain unresolved.
Is Rockdale's groundwater at risk of contamination?
Rockdale 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 62 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 Rockdale's water compare to other cities?
Rockdale ranks #814 out of 882 cities in Illinois (better than 8% of state cities) and #12202 out of 15382 cities nationally (21th percentile). The grade of C- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Rockdale's small water system affect quality?
Rockdale's system serves approximately 2,012 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 62 violations on record.