Waukegan
IL0971900 · serves about 87,149 people · Surface water
✓ No health-based violations✓ Lead below action level✓ No PFAS detected
Lead 90th percentile: 10 ppb (period starting 2026-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
Lake County tap water: hardness, PFAS and lead
Lake County, Illinois has about 718,604 residents (Census 2024 estimate) and 103 community water systems in EPA records. The largest local system is Waukegan, serving about 87,149 people from surface water.
✓ 0 of 6 largest systems with health-based violationsPFAS detected at 0 of 6 sampled systemsHardness 7.6 gpg (high confidence)
Public-record figures, not a test of your tap. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
How hard is Lake County water?
Waukegan Measured (utility report, 2025) · High confidence
7.6 gpg (130 mg/L), hard
Source: WAUKEGAN water quality report, 2025
Public-record figures, not a test of your tap. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
Softener size at 7.6 gpg
For a 3-person home using 57 gallons per person per day and regenerating weekly, you'd remove about 9,097 grains between regenerations. Suggested size: 24,000 grain.
Estimate only. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
Largest water systems in Lake County
The 6 biggest of 103 community water systems on EPA records for this county. Service areas don't follow county lines; your water bill names your provider.
Vernon Hills - Lake Co Pw
IL0971750 · serves about 33,207 people · Surface water
✓ No health-based violations✓ Lead below detection✓ No PFAS detected
Lead 90th percentile: <DL (below the lab detection/reporting limit; reported as 0) (period starting 2021-01-01) Older result. Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
Mundelein
IL0971150 · serves about 31,500 people · Surface water
✓ No health-based violations✓ Lead below action level✓ No PFAS detected
Lead 90th percentile: 4.3 ppb (period starting 2026-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
Gurnee
IL0970350 · serves about 30,193 people · Surface water
✓ No health-based violations✓ Lead below action level✓ No PFAS detected
Lead 90th percentile: 0.3 ppb (period starting 2025-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
Highland Park
IL0970500 · serves about 30,176 people · Surface water
✓ No health-based violations✓ Lead below action level✓ No PFAS detected
Lead 90th percentile: 11 ppb (period starting 2025-07-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
Round Lake Beach
IL0971550 · serves about 27,200 people · Surface water
✓ No health-based violations✓ Lead below action level✓ No PFAS detected
Lead 90th percentile: 4.6 ppb (period starting 2025-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
Public-record figures, not a test of your tap. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
A PFAS detection is not a violation. Federal limits (4 ppt for PFOA and PFOS) apply to running annual averages, with compliance required by 2029. In May 2026 EPA proposed extending the PFOA/PFOS deadline to 2031 and removing other PFAS limits; not final as of 2026-10-21.
Test your own tap
These are public records for whole systems. Your home's pipes, fixtures and any private well can change what you drink. A certified lab test or a hardness test strip gives you your own numbers. Then use our PFAS and lead filter selector to see which certifications to look for.
Common questions about Lake County water
Is tap water in Lake County safe to drink?
None of the 6 largest systems here have a health-based violation in EPA records since October 2021. Waukegan's most recent lead 90th percentile was 10 ppb (2026), below the 15 ppb action level. Public records can't guarantee what comes out of your tap, especially with older plumbing, so a home test is the surest check.
How hard is the water in Lake County?
Waukegan reports about 7.6 grains per gallon (130 mg/L), which is hard. For a 3-person home at 7.6 gpg, our softener calculator suggests a 24,000 grain unit as a starting point.
Is there PFAS in Lake County water?
None of the 6 sampled systems listed here detected PFAS above EPA's reporting levels in UCMR 5 testing.
Which water system serves my address in Lake County?
Most homes are served by Waukegan or one of the other systems listed on this page, but service areas don't follow county lines. Your water bill names your provider, and its annual Consumer Confidence Report has the full test results.
More Illinois counties
Sources for this page
- Water systems, violations since 2021-10-01 and lead results: EPA Safe Drinking Water Information System (SDWIS), 2026 Q3 release. Each system links to its EPA ECHO record.
- PFAS sampling: EPA UCMR 5 (2023–2026 results).
- Hardness: WAUKEGAN water quality report (2025). We cite the figure and link the report; we don't reproduce it.
- Population: U.S. Census Bureau county population estimates (2024).
Data as of October 21, 2026. Figures are copied from public records and combined with our own calculations; they can be out of date or wrong. Tapped Out isn't affiliated with any utility or the EPA. Written and reviewed by the Tapped Out team. How we calculate · All sources.