Is Lemont, IL Tap Water Safe to Drink?
Graded D — but Lead and Strontium were detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
46.8/100
waterverge.com Lemont, IL — Water Quality Report
Lemont's drinking water received a grade of D (46.8 out of 100), indicating poor water quality. The city's 4 water systems serve approximately 18,120 residents using groundwater.
Lead levels were measured at 20.0 ppb (90th percentile), which exceeds the EPA action level of 15 ppb. UCMR 5 testing detected 1 PFAS compound in the water supply.
The system has 85 violations on record, including 26 health-based violations. 20 remain unresolved.
What to know about Lemont's water
Lemont ranks #859 out of 891 cities in Illinois for water quality, placing it among the lowest-rated in the state.
Lemont 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.
PFAS compounds were detected in testing, though levels remain within current EPA limits. Residents seeking extra precaution may consider an activated carbon or reverse osmosis filter.
Lead levels exceed the EPA action level of 15 ppb, which typically indicates aging lead service lines or lead solder in the distribution system. An NSF 53-certified filter is strongly recommended for drinking and cooking water.
The system has seen 8 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Lemont, IL water safe to drink?
Lemont's drinking water has significant quality concerns based on EPA testing data. With a grade of D (46.8/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 4 water systems serve approximately 18,120 residents using groundwater (wells).
Recent water quality updates for Lemont
A timeline of significant water quality events, violations, and data updates.
Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.
Latest EPA compliance and testing data incorporated into Lemont's water quality assessment. Grade: D (46.8/100).
Contaminants: Lead and Copper Rule.
1 health-based. Contaminants: Lead and Copper Rule.
Contaminants: Consumer Confidence Rule.
Federal disaster declaration (FEMA DR-4819). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Lemont's water supply.
Exceeds EPA action level. Lead service line replacement and point-of-use filtration recommended.
Detected but within current EPA limits. PFAS do not break down in the environment and can accumulate in the body over time. An activated carbon filter can reduce exposure.
Violation history
Lemont's water system has 85 total violations on record, including 26 health-based violations. 20 remain unresolved. 8 violations were issued in the last 5 years.
Flood & environmental risk
Cook County has experienced 9 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 Flag Creek, Sawmill Creek, Des Plaines River, Chicago Sanitary And Ship Canal Nr Lemont, Chicago Sanitary And Ship Canal.
Where does Lemont's water come from?
Lemont's drinking water comes from groundwater (wells), supplied by 4 water systems serving approximately 18,120 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Flag Creek (river), Sawmill Creek (river), Des Plaines River (river), Chicago Sanitary And Ship Canal Nr Lemont (river), Chicago Sanitary And Ship Canal (river).
What Lemont residents can do
Recommended: NSF 53-certified pitcher or under-sink filter. This addresses the specific contaminants found in Lemont'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.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
Lemont'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 ↓Forever chemicals overview
National PFAS report →Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Lemont
Industrial polluters nearby
Reported releases to surface water by facilities near Lemont, ranked by pounds discharged annually.
Total reported releases to surface water: 169,751 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
CITGO PETROLEUM CORP LEMONT REFINERY LEMONT, IL60439 | Nitrate compounds (water dissociable; reportable only when in aqueous solution) | 169,739 | 3.9 mi |
K.A. STEEL CHEMICALS INC. D/B/A OLIN CHLOR ALKALI PRODUCTS & LEMONT, IL60439 | Chlorine | 8 | 0.8 mi |
OLDCASTLE PRECAST INC ROMEOVILLE, IL60441 | Manganese compounds | 3 | 6.7 mi |
ARROW GEAR DOWNERS GROVE, IL60515 | Lead | 1 | 9.2 mi |
VALVOLINE GLOBAL - WILLOW SPRINGS WILLOW SPRINGS, IL60480 | — | — | 7.0 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites within 10 miles of Lemont
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.
- LENZ OIL SERVICE INC3.4 mi
Source: EPA Superfund National Priorities List
Flood & disaster history
Cook County has experienced 9 federally declared disasters since 1972. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Lemont's water supply, we recommend the following filter types.
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. | 20.0 | 15 | ppb | Inorganic | Over Limit |
| 11Cl-PF3OUdS | ND | HI | µg/L | PFAS | Not Detected |
| 4:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 6:2 FTS 6:2 FTSPFAS A fluorotelomer sulfonate commonly found at sites contaminated with aqueous film-forming foam (AFFF) used in firefighting. Health EffectsPotential liver toxicity and endocrine disruption. Less studied but identified as a contaminant of concern. EPA LimitNo individual MCL (not yet regulated) Common SourcesFirefighting foam (AFFF), airports, military bases, and industrial facilities. | ND | HI | µg/L | PFAS | Not Detected |
| 8:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 9Cl-PF3ONS | ND | HI | µg/L | PFAS | Not Detected |
| ADONA | ND | HI | µg/L | PFAS | Not Detected |
| HFPO-DA HFPO-DA (GenX)PFAS A replacement for PFOA in manufacturing, marketed as safer but still a persistent "forever chemical." Also known as GenX. Health EffectsLiver and kidney effects, reproductive toxicity, immune system effects, and potential cancer risk. EPA Limit10 ppt MCL Common SourcesFluoropolymer manufacturing (used as PFOA replacement), industrial wastewater discharge. | ND | 0.01 | µg/L | PFAS | Not Detected |
| lithium LithiumInorganic A naturally occurring alkali metal found in groundwater. Monitored under UCMR 5 to assess occurrence in drinking water. Health EffectsKidney effects at high doses. Low-level exposure effects under study; some research suggests neurological effects. EPA LimitNo MCL (monitoring only under UCMR 5) Common SourcesNatural mineral deposits, geothermal water, and industrial discharge. | 53.800 | HI | µg/L | PFAS | Detected |
| NEtFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| NFDHA | ND | HI | µg/L | PFAS | Not Detected |
| NMeFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| PFBA PFBAPFAS One of the shortest-chain PFAS compounds. Very mobile in water and difficult to remove with standard filtration. Health EffectsThyroid effects, potential developmental toxicity. Shorter half-life in body than long-chain PFAS. EPA LimitNo individual MCL (not yet regulated) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and firefighting foam. | ND | HI | µg/L | PFAS | Not Detected |
| PFBS PFBSPFAS A short-chain PFAS used as a replacement for PFOS. While it clears the body faster than long-chain PFAS, it still persists in the environment. Health EffectsThyroid effects, reproductive and developmental toxicity, kidney effects. EPA LimitPart of Hazard Index (1.0) Common SourcesIndustrial discharge, firefighting foam, and as a replacement chemical in manufacturing. | ND | HI | µg/L | PFAS | Not Detected |
| PFDA | ND | HI | µg/L | PFAS | Not Detected |
| PFDoA | ND | HI | µg/L | PFAS | Not Detected |
| PFEESA | ND | HI | µg/L | PFAS | Not Detected |
| PFHpA PFHpAPFAS A medium-chain PFAS compound found in various environmental samples. Less studied than PFOA/PFOS but still considered a contaminant of concern. Health EffectsLiver effects, potential developmental toxicity, and endocrine disruption. EPA LimitPart of Hazard Index (1.0) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and contaminated water sources. | ND | HI | µg/L | PFAS | Not Detected |
| PFHpS | ND | HI | µg/L | PFAS | Not Detected |
| PFHxA PFHxAPFAS A short-chain PFAS replacement chemical widely used after manufacturers phased out longer-chain PFAS. Very commonly detected in water. Health EffectsLiver and kidney effects, potential thyroid disruption. Considered less toxic than long-chain PFAS but still persistent. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial processes, firefighting foam (AFFF), food packaging, and textile treatment. | ND | HI | µg/L | PFAS | Not Detected |
| PFHxS PFHxSPFAS A medium-chain PFAS found in firefighting foam and consumer products. It has a long half-life in the human body, similar to long-chain PFAS. Health EffectsImmune system effects, thyroid disruption, and potential reproductive and developmental harm. EPA LimitPart of Hazard Index (1.0) Common SourcesFirefighting foam (AFFF), waterproof textiles, food packaging, and industrial discharge. | ND | HI | µg/L | PFAS | Not Detected |
| PFMBA | ND | HI | µg/L | PFAS | Not Detected |
| PFMPA | ND | HI | µg/L | PFAS | Not Detected |
| PFNA PFNAPFAS A long-chain PFAS compound used in manufacturing fluoropolymers. It bioaccumulates in the body and is very persistent in the environment. Health EffectsDevelopmental effects, liver toxicity, immune suppression, and potential cancer risk. EPA LimitPart of Hazard Index (1.0) Common SourcesFluoropolymer manufacturing, industrial emissions, and contaminated water sources. | ND | HI | µg/L | PFAS | Not Detected |
| PFOA PFOAPFAS A long-chain PFAS ("forever chemical") once widely used in nonstick coatings and firefighting foam. It persists in the body and environment for years. Health EffectsLinked to kidney and testicular cancer, thyroid disease, elevated cholesterol, and reproductive issues. EPA Limit4.0 ppt MCL Common SourcesIndustrial discharge, firefighting foam (AFFF), nonstick cookware manufacturing, and contaminated groundwater. | ND | 0.004 | µg/L | PFAS | Not Detected |
| PFOS PFOSPFAS A long-chain PFAS compound historically used in stain-resistant coatings and firefighting foam. One of the most studied and persistent PFAS chemicals. Health EffectsLiver damage, immune system suppression, thyroid disruption, increased cholesterol, and potential cancer risk. EPA Limit4.0 ppt MCL Common SourcesFirefighting foam (AFFF), industrial sites, stain-resistant fabric treatments, and contaminated groundwater. | ND | 0.004 | µg/L | PFAS | Not Detected |
| PFPeA PFPeAPFAS A short-chain PFAS compound commonly detected in drinking water. One of the most frequently found PFAS in UCMR 5 monitoring. Health EffectsLess studied than PFOA/PFOS. Potential liver and thyroid effects. Research is ongoing. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial discharge, firefighting foam degradation, and consumer products. | ND | HI | µg/L | PFAS | Not Detected |
| PFPeS | ND | HI | µg/L | PFAS | Not Detected |
| PFTA | ND | HI | µg/L | PFAS | Not Detected |
| PFTrDA | ND | HI | µg/L | PFAS | Not Detected |
| PFUnA | ND | HI | µg/L | PFAS | Not Detected |
Lead level trend (90th percentile)
See how Lemont compares by contaminant
Explore where Lemont ranks among all Illinois cities for specific contaminants.
Water source & infrastructure
Where Lemont's water comes from
Lemont'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 18,120 people through 4 water systems.
Water bodies near Lemont
Lemont is located near 5 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Lemont
| System Name | PWSID | Population | Source |
|---|---|---|---|
| LEMONT | IL0311620 | 17,500 | GW |
| FRANCISCAN SISTERS OF CHICAGO | IL0310110 | 505 | GWP |
| SHERWOOD SHORES CONDOMINIUMS | MI0006042 | 90 | GW |
| BUSY BEE MHP #1 | IL1975195 | 25 | GW |
How Lemont compares
Full Illinois rankings →Lemont's score of 46.8/100 is below the average of 56/100 among major Illinois cities. It outscores 5 of 10 nearby cities.
Nearby cities
View Illinois rankings →About Lemont, IL
Learn more about your water
Guides and resources related to Lemont's water quality findings.
Explore water quality across Cook
Frequently asked questions
Is Lemont, IL tap water safe to drink?
Lemont's water quality earned a grade of D (46.8/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #859 out of 891 cities tested in Illinois.
What contaminants are in Lemont's water?
Lead was measured at 20.0 ppb (90th percentile). 1 PFAS compound was detected. 85 violations are on record.
How is Lemont'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 Lemont?
Yes — lead levels exceed the EPA action level of 15 ppb. We recommend an NSF 53-certified filter or reverse osmosis system. PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.
Where does Lemont's water come from?
Lemont's water is sourced from Groundwater. The city has 4 water systems serving approximately 18,120 residents.
What health violations has Lemont's water system had?
Lemont has 26 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. 20 violations remain unresolved.
Is Lemont's groundwater at risk of contamination?
Lemont 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 85 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 Lemont's water compare to other cities?
Lemont ranks #859 out of 891 cities in Illinois (better than 4% of state cities) and #13833 out of 15744 cities nationally (12th percentile). The grade of D reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.