DuPage County Health Department Laboratory
Homeowner samples
- Coliform Bacteria
Listed on the official state certified laboratory list.
Certified by the Illinois Department of Public Health for drinking water microbiology (IDPH lab 17524; certified list revised December 4, 2025). Accredited by the Illinois EPA Environmental Laboratory Accreditation Program for chemical analysis of drinking water (IL ELAP lab code 100322; primary lab list of December 9, 2025). County health department laboratory: sells bacteria and nitrate sample kits to well owners at the counter (usually to residents of neighboring counties too), with the results explained by the department's environmental health staff; check hours and drop-off days before you sample.
Bacteria samples need a sterile bottle from the lab. Chemistry samples usually take a clean container the lab supplies.
Skip softeners and filters. Remove the aerator, run the water 3 to 5 minutes, then fill without touching the inside of the cap.
Bacteria samples are time-sensitive. Use a cooler with ice packs and hand it in or ship it the same day.
Compare results with EPA drinking water limits. If anything is over, our problem pages explain what it means and how to treat it.
Homeowner samples
Homeowner samples
Homeowner samples