Under the authority of the Safe Drinking Water Act, the Environmental Protection Agency (EPA) has established the Lead and Copper Rule (LCR), which sets special health-based drinking water standards for lead and copper called Action Levels. Tucson Water must ensure that the Levels for these metals are not exceeded in more than 10 percent of the homes sampled. The value that is used to determine compliance with the Action Levels is called the 90th percentile.
Tucson Water's Water Quality Management Division monitors and reports for lead and copper to comply with the LCR. Over many years, lead service lines in our distribution system have been replaced to reduce the risks of exposure to lead in drinking water. High levels of lead and copper are not present in the groundwater and in the Colorado River water that serve as our drinking water sources. Most lead and copper in our system comes from lead-containing solder in older plumbing or from faucets or other water fixtures in homes and businesses.
The LCR requires that the lead and copper samples be collected from household taps used for drinking water. For more information, read our publication "Lead and Your Tap Water" available in English and in Spanish.