Per the Lead and Copper Rule of the Michigan Safe Drinking Water Act, the city is required to periodically sample a number of water taps throughout its system for lead concentration levels. In 2018, the sampling protocol for this routine sampling changed to require multiple samples at each sample location and to exclusively target locations served by lead service lines. The intention of this change was to better detect lead.
According to the rule, if approximately 10% of sites sampled indicate lead concentrations of 15 parts-per-billion (ppb) or greater, the city is required to:
- advise water customers of the results
- provide tips on how to reduce lead exposure
- increase community-wide sampling
Eight of the 30 locations tested during the most recent monitoring period exceeded the 15 ppb ‘Action Level’ threshold, triggering the current advisory. The city’s 90th percentile value for lead concentrations among sites tested was 23 ppb.