County health department lab

Watertown Department of Public Health

Watertown, WI · Jefferson County

Homeowner samplesYou can collect and drop off your own sample
Mail-in kitsNot listed, call to confirm
Walk-in drop offBring the sample to the lab during business hours

Certification and services

State certified
Certification number
128099730
Certified by
Wisconsin drinking water program
Certified for
Microbiological, Chem (nitrate, Arsenic)
Lab type
County Health
Pricing
County health department lab; fees set by the county, usually lower than commercial labs.
Last verified
September 29, 2026

Listed on the official state certified laboratory list.

Tests this lab is certified for

Coliform Bacteria
Nitrate / Nitrite

How to submit a sample

  1. 1
    Call or check the website for the right bottles

    Bacteria samples need a sterile bottle from the lab. Chemistry samples usually take a clean container the lab supplies.

  2. 2
    Collect from a cold tap before treatment

    Skip softeners and filters. Remove the aerator, run the water 3 to 5 minutes, then fill without touching the inside of the cap.

  3. 3
    Keep it cold and deliver within 24 hours

    Bacteria samples are time-sensitive. Use a cooler with ice packs and hand it in or ship it the same day.

  4. 4
    Read the report against the standards

    Compare results with EPA drinking water limits. If anything is over, our problem pages explain what it means and how to treat it.

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