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WaterVerge

Water quality report · updated Jul 2026

Is La Salle, IL Tap Water Safe to Drink?

Graded B- — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do ↓

1 contaminant over a legal limit
10.7 ppb lead, 90th percentile
4 unresolved violations
10K people served by 1 water system

PWSID IL0990300 · high data confidence · local government utility

Reviewed by WaterVerge Editorial Team · Last updated July 2026
B 70.2 / 100

#733 of 882Illinois cities
How we grade →

01The verdict: is La Salle water safe?

La Salle's drinking water has significant quality concerns based on EPA testing data. With a grade of B- (70.2/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 9,700 residents using groundwater (wells).

The concern

Copper is over its legal limit

Measured at 1.40 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 ↓
Context

10K 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 ↓
Keep watching

Lead is approaching its limit

Measured at 10.7 ppb — 71% of the 15 ppb limit. Within the rules, but with less headroom than you'd want.

See the ledger ↓

La Salle's drinking water received a grade of B- (70.2 out of 100), indicating fair water quality. The city's 1 water system serves approximately 9,700 residents using groundwater.

Lead levels were measured at 10.7 ppb (90th percentile), which is within EPA limits but above recommended levels. UCMR 5 testing detected 3 PFAS compounds in the water supply. The system has 52 violations on record, including 6 health-based violations. 4 remain unresolved.

La Salle ranks #733 out of 882 cities in Illinois for water quality, placing it among the lowest-rated in the state. La Salle 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. 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. The system has seen 7 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

How the 70.2/100 breaks down Methodology →
ViolationsHistorical violation record including health-based and monitoring violations.
32.5 / 45C
Lead & CopperLead at 10.7 ppb (90th percentile).
9 / 20D
Contaminants3 PFAS compounds detected.
15.8 / 20B
ComplianceMonitoring and reporting compliance with EPA regulations.
8 / 10B
Source RiskWater source: Groundwater.
5 / 5A

02What's in La Salle's water

Every contaminant flagged in La Salle, 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.

4 detections · sorted by % of legal limit
Over the limit Elevated — watch Within limits
0 50% LEGAL LIMIT 150%
lithium PFAS / Forever Chemical
20.0000 µg/L 120% of limit

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.
Exceeds Limit What to do →
Lithium Inorganic
20.0 µg/L 33% of limit
33 contaminants tested under EPA SDWIS, LCR and UCMR programs · 6 detected

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 10.7 15 ppb Inorganic Near Limit
Copper (90th percentile) 1.40 1.3 mg/L 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 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 ND 0.01 µg/L PFAS Not Detected
lithium 20.000 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 0.007 HI µg/L PFAS Detected
PFBS 0.003 HI µg/L PFAS 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 ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA ND HI µg/L PFAS Not Detected
PFHxS ND HI µg/L PFAS Not Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA ND 0.004 µg/L PFAS Not Detected
PFOS ND 0.004 µg/L PFAS Not Detected
PFPeA 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
Data source: EPA SDWIS, UCMR 5, local utility CCR.

03La Salle'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 52 violations on record, including 6 health-based violations. 4 remain unresolved.

5 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.

6 health-based in 10 yrs 4 monitoring & paperwork 1 still unresolved
PFAS3 PFAS "forever chemical" compounds detectedDetected at levels within current EPA limits. PFAS persist indefinitely in the environment.
UpdateWater quality data updatedLatest EPA compliance and testing data incorporated into La Salle's water quality assessment. Grade: B- (70.2/100).
Violation1 drinking water violation recordedContaminants: Total Haloacetic Acids (HAA5).Resolved
Violation1 drinking water violation recordedContaminants: Revised Total Coliform Rule.Resolved
Violation1 drinking water violation recordedContaminants: Chlorine.Resolved
Lead, 90th percentileppb · lower is better
01020304050EPA action level · 15 ppb1992 — 26 ppb1994 — 42 ppb1995 — 34 ppb1996 — 18 ppb1997 — 13 ppb2000 — 10 ppb2001 — 23 ppb2002 — 9 ppb2003 — 0 ppb2004 — 5 ppb2005 — 10 ppb2008 — 4 ppb2010 — 5.1 ppb2011 — 5.1 ppb2013 — 5.2 ppb2016 — 11 ppb2019 — 6.5 ppb2022 — 7 ppb2023 — 20 ppb2024 — 5.5 ppb2025 — 0 ppb26019922000200520162025

Down 26 ppb since 1992. Latest reading: 0 ppb (2025) — 0% of the action level. Sampled at higher-risk homes (90th percentile).

Copper, 90th percentilemg/L · lower is better
0246EPA action level · 1.3 mg/L1994 — 2.7 mg/L1995 — 4.7 mg/L1996 — 2.0 mg/L1997 — 2.1 mg/L2000 — 2.4 mg/L2001 — 1.8 mg/L2002 — 1.4 mg/L2.71.41994199620002002

Down 1.3 mg/L since 1994. The latest reading (1.4 mg/L, 2002) is over the action level. Sampled at higher-risk homes (90th percentile).

04Where La Salle's water comes from

La Salle's drinking water is drawn from underground aquifers through wells.

Source

Groundwater

Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.

Treatment

Local treatment

Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.

Distribution

1 system

1 water system, operated under local government ownership.

Delivery

9,700 people

Residents served across La Salle'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 9,700 people through 1 water system.

System namePWSIDPopulationSource
LA SALLE IL0990300 9,700 Groundwater

Water bodies near La Salle

Illinois River · river

These water bodies shape the regional watershed and can indirectly affect groundwater quality.

05How La Salle compares

Scores for nearby Illinois cities on one line, with the average marked.

Naperville
81.2 · B+
La Salle (this city)
70.2 · B-
Aurora
45.5 · D
Joliet
38.5 · F
Rockford
38.4 · F
Chicago
35.2 · F

dashed line = Illinois average (55/100)

La Salle scores 70.2/100above the Illinois average of 55/100. It outscores 7 of 10 nearby cities. Full Illinois rankings →

Lasalle water quality rankings
Compare all cities in the county — grades, violations, and contaminant data side by side.

06What to do at home

Steps matched to what testing actually found in La Salle's water — not generic advice.

Because of lead

Filter drinking & cooking water

Activated carbon or reverse osmosis filter. Lead detected at 10.7 ppb

Compare tested filters →
Because lead was detected

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 →
Stay informed

Watch for La Salle alerts

We refresh EPA data monthly and surface new violations, advisories, and boil-water notices for your county on this page.

All water alerts →

Frequently asked questions

Is La Salle, IL tap water safe to drink?

La Salle's water quality earned a grade of B- (70.2/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #733 out of 882 cities tested in Illinois.

What contaminants are in La Salle's water?

Lead was measured at 10.7 ppb (90th percentile). 3 PFAS compounds were detected. 52 violations are on record.

How is La Salle'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 La Salle?

While lead levels are within EPA limits, a filter adds extra protection. PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.

Where does La Salle's water come from?

La Salle's water is sourced from Groundwater. The city has 1 water system serving approximately 9,700 residents.

What health violations has La Salle's water system had?

La Salle has 6 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. 4 violations remain unresolved.

Is La Salle's groundwater at risk of contamination?

La Salle 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 52 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.

Why does La Salle have so many PFAS compounds in its water?

3 different PFAS "forever chemical" compounds were detected in La Salle's water supply during UCMR 5 testing. PFAS contamination often originates from proximity to military installations (AFFF firefighting foam), airports, industrial manufacturing sites, or wastewater treatment facilities. While detected, current levels are within EPA limits. An activated carbon filter can further reduce exposure.

How does La Salle's water compare to other cities?

La Salle ranks #733 out of 882 cities in Illinois (better than 17% of state cities) and #10630 out of 15382 cities nationally (31th percentile). The grade of B- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.

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About La Salle, IL: La Salle or LaSalle is a city in LaSalle County, Illinois, United States, located at the intersection of Interstates 39 and 80. It is part of the Ottawa, IL Micropolitan Statistical Area. Originally platted in 1837 over one square mile, the city's boundaries have grown to 12 sq mi (31 km2). Named in honor of 17th century Illinois valley explorer, the Sieur de La Salle, city boundaries extend from the Illinois River and Illinois and Michigan Canal to a mile north of Interstate 80 and from the city of Peru on the west to the village of North Utica on the east. Starved Rock State Park is located approximately 5 mi (8 km) to the east. The population was 9,582 as of the 2020 census, down from 9,609 at the 2010 census. LaSalle and its twin city, Peru, make up the core of the Illinois Valley. Due to their combined dominance of the zinc processing industry in the early 1900s, they were collectively nicknamed "Zinc City." Wikipedia → Sources: EPA SDWIS & ECHO · UCMR 3–5 · Lead & Copper Rule samples · EPA TRI · U.S. Drought Monitor · FEMA declarations. Data last updated Jul 2026. Analysis by the WaterVerge Editorial Team · methodology.