Is Diamond, IL Tap Water Safe to Drink?
Graded A-, with 6 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
86.1/100
waterverge.com Diamond, IL — Water Quality Report
Diamond's drinking water received a grade of A- (86.1 out of 100), indicating good water quality. The city's 2 water systems serve approximately 3,051 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 86 violations on record, including 20 health-based violations. 6 remain unresolved.
What to know about Diamond's water
Diamond ranks #339 out of 891 cities in Illinois for water quality, placing it mid-range in the state.
Diamond 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, Diamond may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Diamond, IL water safe to drink?
Diamond's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (86.1/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 3,051 residents using groundwater (wells).
Recent water quality updates for Diamond
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Diamond's water quality assessment. Grade: A- (86.1/100).
Contaminants: LEAD AND COPPER RULE REVISIONS.
Contaminants: Chlorine.
Contaminants: TTHM, Total Haloacetic Acids (HAA5).
Federal disaster declaration (FEMA DR-4116). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-3230). Hurricane event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Diamond's water supply.
Well within EPA limits.
Violation history
Diamond's water system has 86 total violations on record, including 20 health-based violations. 6 remain unresolved. 1 violation was issued in the last 5 years.
Flood & environmental risk
Grundy County has experienced 5 federally declared disasters since 1972. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Kankakee River, Des Plaines River, Aux Sable Creek, Mazon River, Kankakee R.
Where does Diamond's water come from?
Diamond's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 3,051 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Kankakee River (river), Des Plaines River (river), Aux Sable Creek (river), Mazon River (river), Kankakee R (river).
What Diamond residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Diamond's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Diamond's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Diamond
Industrial polluters nearby
Reported releases to surface water by facilities near Diamond, ranked by pounds discharged annually.
Total reported releases to surface water: 510,844 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
EXXONMOBIL OIL CORP JOLIET REFINERY CHANNAHON, IL60410 | Nitrate compounds (water dissociable; reportable only when in aqueous solution) | 510,736 | 9.1 mi |
NOURYON SURFACE CHEMISTRY LLC MORRIS, IL60450 | Ammonia | 57 | 9.5 mi |
EQUISTAR CHEMICALS LP MORRIS, IL60450 | Polycyclic aromatic compounds | 50 | 9.8 mi |
AMERICAS STYRENICS LLC - JOLIET SITE CHANNAHON, IL60410 | Zinc compounds | 1 | 8.9 mi |
DIVERSIFIED CPC INTERNATIONAL INC CHANNAHON, IL60410 | — | — | 8.8 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites within 10 miles of Diamond
Superfund sites nearby
Federally tracked hazardous-waste sites on the EPA National Priorities List. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.
- JOLIET ARMY AMMUNITION PLANT MANUFACTURING AREA8.0 mi
Source: EPA Superfund National Priorities List
Flood & disaster history
Grundy County has experienced 5 federally declared disasters since 1972. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
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 |
Lead level trend (90th percentile)
See how Diamond compares by contaminant
Explore where Diamond ranks among all Illinois cities for specific contaminants.
Water source & infrastructure
Where Diamond's water comes from
Diamond's drinking water is drawn from underground aquifers through wells.
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 3,051 people through 2 water systems.
Water bodies near Diamond
Diamond is located near 5 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Diamond
| System Name | PWSID | Population | Source |
|---|---|---|---|
| DIAMOND | IL0630250 | 2,508 | GW |
| BURT ESTATES MHC | IL0630070 | 543 | GWP |
How Diamond compares
Full Illinois rankings →Diamond's score of 86.1/100 is above the average of 56/100 among major Illinois cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Illinois rankings →About Diamond, IL
Learn more about your water
Guides and resources related to Diamond's water quality findings.
Explore water quality across Grundy
Frequently asked questions
Is Diamond, IL tap water safe to drink?
Diamond's water quality earned a grade of A- (86.1/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #339 out of 891 cities tested in Illinois.
What contaminants are in Diamond's water?
Lead was measured at 0.0 ppb (90th percentile). 86 violations are on record.
How is Diamond'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 Diamond?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Diamond's water come from?
Diamond's water is sourced from Groundwater. The city has 2 water systems serving approximately 3,051 residents.
What health violations has Diamond's water system had?
Diamond has 20 health-based violations 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. 6 violations remain unresolved.
Is Diamond's groundwater at risk of contamination?
Diamond 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 86 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 Diamond's water compare to other cities?
Diamond ranks #339 out of 891 cities in Illinois (better than 62% of state cities) and #4927 out of 15744 cities nationally (69th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.