Environmental Water Lab

About 20,000 homes and 200 businesses within DuPage County are served by water wells. The water laboratory supports the activities of the Environmental Health Services unit by testing drinking water for bacteria, nitrate and hardness. The water laboratory is certified by the Illinois Department of Public Health (certification Number 17544) for the examination of Total Coliform and E Coli in drinking water supplies using the Colilert P/A and Quanti-Tray methods.

Bacteria Indicators

Generally, coliforms are bacteria that are not harmful and are naturally present in the environment. They are used as an indicator that other, potentially harmful, fecal bacteria (indicated by E coli) could be present. The presence of coliform bacteria in water suggests that there could be a problem with existing equipment or treatment systems, contamination of the source water or a breach in the distribution system that could introduce E coli contamination.

Private Water Well Testing

The Health Department offers private water well testing for Coliform bacteria and nitrate screening. See the Fees page for additional testing available. Residents may stop by a Public Health Center in Addison, Lombard, Westmont or Wheaton to pick up water well testing supplies and instructions, as well as to drop off their samples.

More Information

For additional information about the water laboratory, please call  630-221-7593.

Last Reviewed: 8/18/2023