Skip to main content

Water Supply Lead Results

Water supply lead results

You can see the latest lead testing results for your community water supply in the table below. To help you understand the table, here are descriptions of the last few column headings.

Last Monitoring Period End

This date gives you an idea when the water supply last tested for lead. It technically means the final day of the water supply’s last scheduled monitoring period. Samples can be collected at any time during this period.

Lead 90th Percentile (ppb)

This number is calculated from all the lead sample results taken at sites within a water system during a monitoring period. If your water supply’s 90th percentile number is over 15 ppb, your community has a lead Action Level Exceedance (ALE) and must take corrective action.

Includes 5th Liter?

Under Michigan’s revised Lead and Copper Rule, water supplies are required to do “5th liter sampling” at buildings that have lead service lines or lead pipes. This means that in addition to testing the first liter of water from the tap, they must also test the fifth. The fifth liter is intended to be more representative of water in contact with the service line.

Fifth liter infographic - sampling at homes with lead service lines

Sampling Next Due

This is the next date that water samples must be collected and tested. It is based on current sampling schedules and is subject to change at any time.

The water supply lead results dataset is available for download on the open data portal.