Aurora issues public notice after new testing finds 90th-percentile lead level above federal action level

Aurora officials told the City Council’s Committee of the Whole on July 15 that new 2025 lead‑in‑drinking‑water testing produced results that triggered a required public notice and changes to the city’s replacement timeline. Jason Bauer, director of public works, said the city completed 100 fifth‑liter samples from January through June and that the 90th‑percentile result was 20.6 parts per billion, above the 15 ppb action level used to determine compliance.

The city issued a public notice through news outlets after exceeding the action level, Bauer said, and is expanding work it said it already had underway: replacing lead service lines and conducting a corrosion‑control study. “The water in the plant is lead free,” Bauer said. “Where lead gets into the system is in the service lines. Replacing the lead service lines is the only thing that’s within the purview of the water utility.”

Why it matters: the federal action level — 15 ppb — is the compliance threshold that, when exceeded at the 90th percentile of required samples, triggers required public notification and additional corrective steps by a water utility.

What the city reported: Bauer said Aurora has been doing partial replacements and voluntary replacements for years…