EPA is working with states and public water systems to reduce exposure to lead in drinking water. A service line is the pipe that carries drinking water from water mains to buildings, including homes. When present in a water system, lead service lines (LSLs) are a key source of lead in drinking water. Under the Lead and Copper Rule Revisions (LCRR), EPA required public water systems to conduct inventories detailing the service line materials present in their distribution system; systems were required to submit this data to their respective state/primacy agency, who then submitted the data to EPA.

This report presents state/primacy agency reporting for each public water system's service line counts to date, in the following categories:

• Lead service lines — where all or a portion is made of lead.
• Galvanized requiring replacement (GRR) — made from iron or steel dipped in zinc, which lead can adhere to over time from nearby lead sources.
• Non-lead service lines.
• Service lines made of unknown materials.

EPA estimates that there are approximately 4 million lead service lines in the US. Of these, 3 million are confirmed as containing lead, as reported by states (this number is the sum of “Galvanized Requiring Replacement Service Lines” and “Lead Service Lines”). However, there are many service lines that contain unknown materials; of these, EPA estimates that 1 million are likely to contain lead – resulting in a best estimate of 4 million lead service lines. EPA made this estimation using the same methodology as previous years, just with improved data from the inventories.

For more information and resources on that estimate, please visit EPA's 7th Drinking Water Infrastructure Needs Survey and Assessment.

For more information on lead in drinking water, as well as Lead and Copper Rule requirements and compliance assistance, visit our webpages Basic Information About Lead in Drinking Water and Lead and Copper Rule Implementation Tools.