Wisconsin Water Quality Records

System types

Who these systems serve

Community systems serve people where they live: 610 municipal systems and 417 other-than-municipal systems, such as apartment buildings and mobile home parks.

Non-community systems include 894 that regularly serve the same people, such as schools and workplaces, and 9,264 that serve changing visitors, such as campgrounds and restaurants.

Water sources

Groundwater and surface water

The report counts 11,125 systems using groundwater and 60 using surface water. A count of systems is different from a count of people: a large lake-fed system can serve many more people than a small well-based system.

Source-water protection focuses on preventing contaminants from entering wells and surface-water supplies. It complements the test results reported for treated drinking water.

Explore DNR source-water protection resources

Find the record

Search by system name or PWSID

1. Open the portal and choose Public Water Systems.
2. Enter the provider name or full PWSID in PWS Name or ID, then select Search.
3. Compare the returned name and PWS ID with your bill or official notice, then open the matching result.
4. Choose the relevant record section, such as Lead/Copper Samples, Other Chemical Samples, or Violations. Check dates and units before interpreting a result.

Worked example · PWSID 24101000

Milwaukee Water Works

Searching 24101000 returns MILWAUKEE WATERWORKS. The record links to its Consumer Confidence Report and has separate sections for test results, violations, and Public Notice Requirements.

The number 152454 in this record's web address is the portal's internal identifier. Use 24101000 as the PWSID when comparing records. Confirm service to your address with the provider; the record's city and mailing address do not define its service boundary.

Reports and notices

Separate annual reports from current instructions

Use the Consumer Confidence Report link on the DNR system record or the utility's report archive. Match both the system and the reporting year. If a report is missing or difficult to use, ask the utility for the year and format you need.

For current instructions, check your provider's notices and contact the provider directly. The portal's Public Notice Requirements section tracks regulatory requirements; it is not a complete live emergency-alert feed. Ask the provider which alerts or subscriptions cover your address.

Lead

Check service lines and testing separately

Ask your utility for its service-line inventory and the material recorded for your address. A system's lead and copper monitoring results do not identify every property's pipe material or measure every household tap.

DNR lists lead service-line replacement funding routes for municipalities. Your utility must confirm whether a local program is available and what costs or conditions apply to your property.

Review replacement funding information

PFAS

Use the drinking-water data layer

DNR's PFAS Interactive Data Viewer includes municipal drinking-water testing alongside other information, including contamination sites and fish advisories. Identify the dataset and collection date before comparing locations; a nearby map marker is not a result for your tap.

A result and a regulatory limit are different pieces of information. Use DNR's current PFAS guidance for the applicable regulatory context.

Read current DNR PFAS guidance

Private wells

Use a well-specific testing pathway

A private domestic well is not covered by a neighboring utility's annual report. DNR's private-well guide explains routine testing and how to arrange a test. Contact a laboratory certified for the contaminant you want tested and follow its collection instructions.

DNR lists bacteriological and chemical laboratories separately. Confirm the test, collection kit, delivery requirements, and cost directly with the lab.

Find certified drinking-water laboratories