Guides

• How to Read Your Water Utility's Lead Result — What a 90th-percentile lead result is, why the sampled homes are the worst-case ones, what "not detected" means, and why none of it tells you what your own pipe is.
• The 10 ppb Lead Rule: Which Water Systems It Changes in 2027 — EPA's Lead and Copper Rule Improvements drop the action level from 15 to 10 ppb in November 2027. 650 systems sit in the band that changes.
• Why Small Water Systems Go Over the Lead Limit More Often — Lead exceedances by water-system size, from EPA records: very small systems exceed the action level at several times the rate of big-city utilities.
• Over the Lead Limit Before, Under It Now: What That Means — 2,878 US water systems have exceeded the lead action level at least once; 2,326 are under it in their latest result. Why the old exceedance still matters.