County · Illinois

McHenry County, Illinois: drinking water records

Name: Drinking water records for McHenry County, Illinois
Creator: U.S. Environmental Protection Agency
License: https://www.usa.gov/government-works

Explore EPA records for 32 community water systems across 18 ZIP codes in McHenry County, then find water-testing resources and available recent monitoring-station readings.

In focus32Community water systems

Public records. Clearer context.

Data as of EPA UCMR 5 final release, August 2026 (file dated Aug 28, 2026) · EPA SDWIS 2026Q2 (file dated Jul 9, 2026). How we build these pages

Drinking-water records

EPA survey and compliance records are historical reports. UCMR 5 results are available for 12 of the 32 listed systems in this snapshot. A system with no reported PFAS detection is not a test of every tap or every contaminant.

systems in EPA's PFAS survey

systems where PFAS was found

systems at or above the PFOA or PFOS limit, on the yearly-average basis EPA uses

systems that have reached the lead action level

systems with a health-based violation since 2016

System population figures are summed from EPA registry records and can overlap where wholesalers and retail systems serve the same people. They are not a Census county-population estimate.

Water systems in this county

All 32 active community systems in the available county records, sorted by record completeness. Scroll the table to explore more systems.

Water system	People served	PFAS survey results	PFAS found	Health-based violations	Lead, 9 in 10 homes at or below
Huntley IL1110350	28,495	300	0	1	1 ppbbelow the action level
Woodstock IL1110950	25,630	120	0	1	7 ppbbelow the action level
Prairie Path Water Co-Whispering Hills IL1115700	8,300	300	7	1	0 ppbbelow the action level
Fox River Grove IL1110200	4,702	120	4	1	7.2 ppbbelow the action level
Wonder Lake IL1115750	3,870	180	0	1	1.8 ppbbelow the action level
Crystal Lake IL1110150	40,661	300	2	0	7.7 ppbbelow the action level
Algonquin IL1110050	30,700	240	0	0	2.3 ppbbelow the action level
Lake in the Hills IL1110400	28,661	480	0	0	2.7 ppbbelow the action level
Mchenry IL1110600	22,335	240	1	0	4.1 ppbbelow the action level
Cary IL1110100	17,826	330	5	0	4.1 ppbbelow the action level
Harvard IL1110250	9,469	180	0	0	1.4 ppbbelow the action level
Marengo IL1110650	7,572	120	1	0	0 ppbbelow the action level
Lakewood IL1115760	4,267	0	0	0	1.5 ppbbelow the action level
Richmond IL1110750	2,089	0	0	0	8.7 ppbbelow the action level
Wonder Lake (Niu) IL1115850	1,950	0	0	0	0 ppbbelow the action level
Aqua Illinois-Mchenry Shores IL1115020	1,862	0	0	0	3.3 ppbbelow the action level
Hebron IL1110300	1,368	0	0	0	4.5 ppbbelow the action level
Prairie Path Water Company-Killarney IL1115400	1,232	0	0	0	2.4 ppbbelow the action level
Johnsburg No.2 IL1115080	1,124	0	0	0	0 ppbbelow the action level
Oakbrook Estates MHP IL1115125	1,012	0	0	0	0 ppbbelow the action level
Prairie Path Water Company-Holiday Hills IL1115350	868	0	0	0	2.7 ppbbelow the action level
Aqua Illinois-Crystal Clear Water Co. IL1115150	855	0	0	0	4.7 ppbbelow the action level
Prairie Path Water Company-Walk Up Woods IL1115800	775	0	0	0	3.3 ppbbelow the action level
Aqua Illinois-Eastwood Manor IL1115250	728	0	0	0	0 ppbbelow the action level
Il American-Terra Cotta IL1110080	681	0	0	0	1 ppbbelow the action level
Union IL1110900	594	0	0	0	1.8 ppbbelow the action level
Aqua Illinois-Nunda IL1115600	485	0	0	0	4.5 ppbbelow the action level
Johnsburg 1 IL1110040	174	0	0	0	2.1 ppbbelow the action level
Royal Oaks MHP IL1115145	170	0	0	0	5.2 ppbbelow the action level
Prairie Ridge Association IL1115730	148	0	0	0	0 ppbbelow the action level
Harbor Lites-Pistakee Fshg Cl IL1110011	132	0	0	0	0 ppbbelow the action level
Valley Hi Nursing Home IL1115189	125	0	0	0	0 ppbbelow the action level

USGS · Monitoring stations

The water, more recently.

Available station readings in McHenry County, Illinois. Each measurement keeps its time, unit and original source.

These readings describe water at a monitoring station. They do not test your tap, measure PFAS or lead, or determine whether water is safe to drink or swim in.

Recent observations load when this section comes into view.

How these readings update

We check for updates every 10 minutes while this section is visible and show supported observations from the last 48 hours. The time beside a reading is when USGS measured it; the checked time is when our service retrieved the response. We mark a reading more than 6 hours old as older. Provisional observations can change after USGS review. A missing reading does not mean zero or clean water.

Temperature, pH, dissolved oxygen, turbidity, conductivity, streamflow and water level are shown only where a station reports them. Different measurements have different units and sampling intervals. USGS data and documentation.

Your next step

Water testing, reports & local help.

Use these official directories to find your drinking-water agency, a certified laboratory and public water records. We have not yet added an individually reviewed local resource list for this county.

Official national directories

Water testing

Find your state’s private-well program

EPA’s state directory points well owners to local program information. Services and eligibility vary by state and county.

U.S. Environmental Protection Agency
Source reviewed 2026-09-15 · Source updated 2026-08-05

Water testing

Find a certified drinking-water laboratory

Use EPA’s directory to reach your state’s laboratory certification program. EPA does not provide on-request testing of residential drinking water.

U.S. Environmental Protection Agency
Source reviewed 2026-09-15 · Source updated 2026-08-11

Public records

Find your utility’s Consumer Confidence Report

EPA links to community water-system reports and explains how to read them. Look for your actual supplier rather than assuming every address in a county shares one system.

U.S. Environmental Protection Agency
Source reviewed 2026-09-15 · Source updated 2026-09-09

Public records

Explore USGS water observations

Find current and historical observations from USGS monitoring locations, including available stream, lake, and groundwater data. Measurements vary by station and do not replace a test of your household water.

U.S. Geological Survey
Source reviewed 2026-09-15

A county overview cannot identify every property’s water provider. If you use a public water system, confirm its name on your bill and request its annual Consumer Confidence Report. Private wells need their own testing; public-system records do not describe a private well.

Understand water testing and laboratory reports

Resource descriptions are compiled by Tap Water Lookup. Review dates describe our source check, not a new water sample. How we review sources · Suggest a correction

Explore your area

Local coverage in McHenry County

18ZIP areas in this overview

Explore the water-system records, recent station readings and testing resources on this county page. They describe the systems and stations identified in each section; they are not a separate water test for every community.

Towns and communities

Algonquin
Cary
Crystal Lake
Fox River Grove
Harvard
Hebron
Huntley
Johnsburg
Lake in the Hills
Marengo
McHenry
Richmond
Ringwood
Spring Grove
Union
Wonder Lake
Woodstock

Explore water-system records Find water-testing resources

View ZIP areas and understand coverage

60012Crystal Lake
60013Cary
60014Crystal Lake
60021Fox River Grove
60033Harvard
60034Hebron
60050McHenry
60051Johnsburg
60071Richmond
60072Ringwood
60081Spring Grove
60097Wonder Lake
60098Woodstock
60102Algonquin
60142Huntley
60152Marengo
60156Lake in the Hills
60180Union

These Census ZIP Code Tabulation Areas are grouped here by their largest county overlap. A ZIP area can cross county lines and contain several water suppliers or private wells. Place labels reflect Census geography, not verified postal city names or utility service boundaries.

Records for these areas are currently presented in this county overview rather than individual ZIP reports. An unpublished report does not mean there are no water records. Confirm your supplier on your water bill; if you use a private well, testing your own well is the relevant next step.

Beyond this county page

Keep reading. Compare nearby.

PFASChoosing a PFAS filterPFAS was found in 6 of the 12 systems EPA surveyed here. See how to check a filter’s certified PFAS reduction.LeadChoosing a lead filter15 systems here have reached the lead action level. See how to check a filter’s lead-reduction certification.Your utilityFind your annual water reportConfirm the supplier on your bill, then read its Consumer Confidence Report for local results.

Counties near McHenry County

All Illinois counties

Sources and scope

EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Database prepared 2026-09-03.

Counts cover the systems that report this county to EPA. A water system may cross county lines. "Found" means at least one result at or above the laboratory reporting level; it is not a compliance finding.

Compiled by Tap Water Lookup from the sources identified on this page. Read the methodology and review process.