WaterVerge

Is Island Lake, IL Tap Water Safe to Drink?

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

8K residents served 1 water system PWSID: IL0974540
Overall Score
87.5 / 100
Violations
1 active
Last Updated
May 2026
Source
Groundwater
#265 of 891 in Illinois Top 26% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
A-GRADE
Water Quality Grade
87.5/100
waterverge.com
A- 87.5/100

Island Lake, IL — Water Quality Report

Island Lake's drinking water received a grade of A- (87.5 out of 100), indicating good water quality. The city's 1 water system serves approximately 8,066 residents using groundwater.

Lead levels were measured at 2.3 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 1 PFAS compound in the water supply.

The system has 4 violations on record, including 1 health-based violation. 1 remains unresolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Island Lake's water

Island Lake ranks #265 out of 891 cities in Illinois for water quality, placing it mid-range in the state.

Island Lake 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.

Quality Breakdown

Water quality score

See methodology →
87.5 out of 100 Grade A-
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
43.8/45
A
Historical violation record including health-based and monitoring violations.
Lead & Copper
16/20
B
Lead at 2.3 ppb (90th percentile).
Contaminants
17.8/20
B
1 PFAS compound detected.
Compliance
5/10
D
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Island Lake, IL water safe to drink?

Use Caution

Island Lake's tap water meets most EPA standards but has areas that warrant attention. With a grade of A- (87.5/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 8,066 residents using groundwater (wells).

1
Active Violations
2.3 ppb
Lead (90th %ile)
1 compound
PFAS Detected
5 events
Disaster History

Recent water quality updates for Island Lake

A timeline of significant water quality events, violations, and data updates.

PFAS
1 PFAS "forever chemical" compound detected

Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Island Lake's water quality assessment. Grade: A- (87.5/100).

Violation
1 drinking water violation recorded

Contaminants: Toxaphene.

Disaster
SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING

Federal disaster declaration (FEMA DR-4116). Flood event — may have impacted local water infrastructure.

Disaster
HURRICANE KATRINA EVACUATION

Federal disaster declaration (FEMA DR-3230). Hurricane event — may have impacted local water infrastructure.

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Coliform (TCR).

Key contaminant findings

Based on the most recent EPA sampling data for Island Lake's water supply.

Lead Within Limits
Detected: 2.3 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

Copper Exceeds Limit
Detected: 1.96 mg/L Limit: 1.3 mg/L (EPA Action Level)

Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.

PFAS (1 compound) Elevated
Detected: Highest: lithium at 12.0000 µg/L Limit: 0.004 µg/L (EPA MCL)

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

Island Lake's water system has 4 total violations on record, including 1 health-based violation. 1 remain unresolved. 1 violation was issued in the last 5 years.

MRMCL
Most recent violations:
Jan 2023 Toxaphene Resolved
Sep 1997 Coliform (TCR) Resolved
Oct 1992 Coliform (TCR) Resolved

Flood & environmental risk

Lake County has experienced 5 federally declared disasters since 1973. 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 Fox Lake, Nippersink Lake, Fox River, Boone Creek, Fox River (Tailwater).

SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING
Flood FEMA DR-4116
HURRICANE KATRINA EVACUATION
Hurricane FEMA DR-3230
SEVERE STORMS & FLOODING
Flood FEMA DR-997

Where does Island Lake's water come from?

Island Lake's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 8,066 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Fox Lake (lake), Nippersink Lake (lake), Fox River (river), Boone Creek (river), Fox River (Tailwater) (river).

What Island Lake residents can do

Request your utility's CCR

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.

Monitor alerts during storms

Island Lake'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.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
2.3 ppb
EPA Action Level: 15 ppb · 15% of limit
Safe Level
Copper (90th percentile)
Inorganic
Over Limit
1.96 mg/L
EPA Action Level: 1.3 mg/L · +20% over limit
Exceeds Limit
lithium
PFAS / Forever Chemical
Near MCL
12.0000 µg/L
EPA MCL: 0.004 µg/L · +20% over limit
Detected
Lithium
Inorganic
Detected
12.0 µg/L
State screening level: 60 µg/L · 20% of limit
DetectedNo federal MCLUCMR 5 Data (2023–2025)
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
1
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

4
Total violations
1
Health-based
1
Active / unresolved
Jan 2023
Most recent violation
Compliance Record

Violations & advisories

4 Total
1 Active
1 Health-based
3 Resolved
Violations by category
Total Coliform Rule
2
Synthetic Organic Chemicals
1
Active
Compliance Violation
Monitoring 0
Jan 2023 Resolved
Toxaphene
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2025
Sep 1997 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Sep 1997
Oct 1992 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Oct 1992
Industrial pollution

Top industrial polluters within 10 miles of Island Lake

Industrial polluters nearby

Reported releases to surface water by facilities near Island Lake, ranked by pounds discharged annually.

FacilityTop chemicalTo surface water (lbs/yr)Distance
MATHEWS CO
Machinery · NA
CRYSTAL LAKE, IL60012
5.8 mi
AMPAC FLEXIBLES LLC (PREVIOUSLY FLEXICON INC)
Plastics and Rubber · PROAMPAC HOLDINGS INC
CARY, IL60013
5.5 mi
TRUE VALUE MANUFACTURING
Chemicals · TRUE VALUE CO
CARY, IL60013
5.4 mi
G & M MANUFACTURING CORP
Fabricated Metals · NA
CRYSTAL LAKE, IL60014
6.5 mi
JOHN CRANE INC
Miscellaneous Manufacturing · JOHN CRANE INC
CRYSTAL LAKE, IL60014
6.6 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Site context

Superfund sites within 10 miles of Island Lake

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.

Source: EPA Superfund National Priorities List

Environmental Risk

Flood & disaster history

5
Declared disasters
May 2013
Most recent
Flood
Most common type

Lake County has experienced 5 federally declared disasters since 1973. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

May 2013
SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING
Flood FEMA #4116
Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3230
Jul 1993
SEVERE STORMS & FLOODING
Flood FEMA #997
Oct 1986
SEVERE STORMS & FLOODING
Flood FEMA #776
Apr 1973
SEVERE STORMS & FLOODING
Flood FEMA #373

Recommended water filters

Based on contaminants detected in Island Lake's water supply, we recommend the following filter types.

🧪
For PFAS
Reverse Osmosis or Activated Carbon Block
1 PFAS compound detected
🔧
For Copper
Reverse Osmosis or KDF Filter
Copper exceeds the EPA action level of 1.3 mg/L

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 2.3 15 ppb Inorganic Safe
Copper (90th percentile) 1.96 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 12.000 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 ND HI µg/L PFAS Not Detected
PFBS 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 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.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 0.0 ppb from 1993 (0.0 ppb) to 2025 (0.0 ppb).

Copper level (90th percentile)

Latest reading: 1.960 mg/L (1993)

EPA action level: 1.3 mg/L

Contaminant Rankings

See how Island Lake compares by contaminant

Explore where Island Lake ranks among all Illinois cities for specific contaminants.

Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Local Government
Population Served
8,066
Water Systems
1
Water Source

Where Island Lake's water comes from

Groundwater

Island Lake'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 8,066 people through 1 water system.

Local Hydrology

Water bodies near Island Lake

Island Lake is located near 5 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.

Fox Lake
lake
Nippersink Lake
lake
Fox River
river
Boone Creek
river
Fox River (Tailwater)
river
Infrastructure

Water systems serving Island Lake

System Name PWSID Population Source
ISLAND LAKE IL0974540 8,066 GW
Regional Comparison

How Island Lake compares

Full Illinois rankings →

Island Lake's score of 87.5/100 is above the average of 56/100 among major Illinois cities. It outscores 9 of 10 nearby cities.

Island Lake (this city)
87.5
Chicago
35.2
Aurora
45.5
Joliet
38.5
Naperville
81.2
Champaign
91.9
Illinois avg
56
City Profile

About Island Lake, IL

Wikipedia →

Island Lake is a village in Lake and McHenry counties in the U.S. state of Illinois. Per the 2020 census, the population was 8,051. The village surrounds Island Lake, a lake which contains a small island.

Economic Profile
$91,852
Median Income
$221,720
Median Home Value
$1,754/mo
Median Rent
6.7%
Unemployment
Community
40.2
Median Age
927
People / sq mi
27.2%
College Educated
81%
Homeownership
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Frequently asked questions

Is Island Lake, IL tap water safe to drink?

Island Lake's water quality earned a grade of A- (87.5/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #265 out of 891 cities tested in Illinois.

What contaminants are in Island Lake's water?

Lead was measured at 2.3 ppb (90th percentile). 1 PFAS compound was detected. 4 violations are on record.

How is Island Lake'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 Island Lake?

PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.

Where does Island Lake's water come from?

Island Lake's water is sourced from Groundwater. The city has 1 water system serving approximately 8,066 residents.

What health violations has Island Lake's water system had?

Island Lake has 1 health-based violation on record. The most recent violation was recorded in January 2023. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 1 violation remains unresolved.

Is Island Lake's groundwater at risk of contamination?

Island Lake 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 4 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 Island Lake's water compare to other cities?

Island Lake ranks #265 out of 891 cities in Illinois (better than 70% of state cities) and #3999 out of 15744 cities nationally (75th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.