Where are the lead service lines?

There are an estimated 9.2 million homes across the U.S. with lead service lines (LSLs)—lead pipes connecting the home to the drinking water main in the street. The only long-term solution to protect public health is to remove these lead pipes. As we remove the lead pipes we know about, we also need to figure out where the rest are.

Most communities have a general sense of how many LSLs they have and what neighborhoods have them. Water utilities base their estimates on:

• Installation and maintenance records,
• Size and age of the service line and
• Professional experience supplemented with field investigations

However, knowing the locations of LSLs is especially difficult for older neighborhoods where records are particularly weak and there are long histories of repairs. Water utilities are also more likely to have records describing the portion of the service line on public property than private property – which is typically considered the responsibility of the homeowner.

Developing and refining estimates of known and potential LSLs to document and share what utilities know – and do not know – about LSLs with their customers and the public is a difficult, but critical, step in creating an effective LSL replacement program. EDF recognizes states and communities across the country that are making progress towards LSL replacement, including by developing estimates of the known and potential LSLs within the state and the utility and making the information on LSL locations public through online city-level maps.

States play an important role in collecting and communicating information. 10 states have surveyed utilities operating community water systems in their state to acquire information such as the number of known and potential LSLs in each system. While some of these states have made this information available online in some form, few have created a state-level map to communicate with the public.

Of the 10 states, we found that Indiana has one of the most robust surveys and a good response rate (for those states for which we were able to acquire data). Using Indiana as a model, we created a map of all utilities in the state based on their response to the state’s survey.