Tap Water Results

Is McHenry, IL tap water safe?

Data: U.S. EPA · How we read the data · How we check it

Summary

No federal limits exceeded in EPA data for McHenry Water System. 1 PFAS were detected below the limits.

2 public water systems serve parts of McHenry. The largest, McHenry Water System, serves 22,335 people, and one system here had PFAS above a federal limit. Your water bill names your system.

Largest system

McHenry Water System

22,335 people · Groundwater · EPA ID IL1110600

PFASHighest averageLimitStatus
PFOA
Not detected
–4 pptNot detected
PFOS
Not detected
–4 pptNot detected
PFHxS
Not detected
–10 pptNot detected
PFNA
Not detected
–10 pptNot detected
HFPO-DA (GenX)
Not detected
–10 pptNot detected

ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.

Lead: 6.7 ppb at the 90th percentile (Jun 2026, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 0

Across Illinois, 13 of 479 water systems EPA tested had PFAS above a 2024 federal limit, and 18 systems were above the lead action level in results from the last five years. Illinois results.

McHenry homes and lead pipes

39%
of homes built before 1980 (Illinois 64%, US 50%)
6%
built before 1950 (Illinois 26%)
26%
of households rent (Illinois 33%)

Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. How to check your own line.

Housing: Census American Community Survey 2020–2024 5-year estimates for McHenry city (tables B25034, B25003). Estimates for small places have a margin of error.

Other water systems serving McHenry

How nearby cities compare

CityMain water systemPFASLead (90th pct.)
Woodstock 8 mi
Woodstock Water System
Woodstock Water SystemNone above limits7 ppb
Crystal Lake 8 mi
Crystal Lake Water System
Crystal Lake Water SystemNone above limits6.8 ppb
Lake in the Hills 11 mi
Lake in the Hills Water System
Lake in the Hills Water SystemNone above limits2.7 ppb
Round Lake Beach 11 mi
Round Lake Beach Water System
Round Lake Beach Water SystemNone above limits4.6 ppb
Algonquin 12 mi
Algonquin Water System
Algonquin Water SystemNone above limits1.96 ppb
Huntley 14 mi
Huntley Water System
Huntley Water SystemNone above limits1.1 ppb
McHenry ZIP codes (1)
  • 60050

Questions

Is McHenry tap water safe to drink?

McHenry Water System has had no health-based violations since 2016. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.

Who supplies water in McHenry, IL?

2 public water systems serve parts of McHenry. The largest is McHenry Water System (22,335 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.

Does McHenry tap water have PFAS?

McHenry Water System had 1 PFAS detected at least once in EPA's 2023–2025 testing, all with averages below the federal limits.

Do McHenry homes have lead pipes?

Census estimates put 39% of McHenry homes as built before 1980 (Illinois: 64%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. McHenry Water System's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.