Sleuthing the Service Lines

“We have about 330,000 service lines—so we had our work cut out for us,” said Jordan Basham, Louisville Water Director of Infrastructure Planning and Records.

The Environmental Protection Agency (EPA), as part of the Lead and Copper Rule Revisions (LCRR), required all U.S. utilities to submit an inventory categorizing the material of water service lines in their system per EPA categories by October 16, 2024.

Louisville Water met the regulation and published its inventory (and the company even is helping customers replace their private lead service lines for free), but categorizing all the service line material on customers’ property took more than a year of intense effort and a lot of detective work using a wide array of research material.

“Louisville Water GIS [Geographic Information Systems] staff used historic aerial imagery and historic planimetric/topographic GIS layers, including building footprint data, parcel data, and subdivision data,” Basham explained. “Staff also used Greater Louisville Area Realtors databases and historic Sanborn fire insurance maps as well as statistical analysis methodologies to properly date structure construction.” 

“One key determination in this process was whether or not a structure existed prior to the year 1988, which is when the Commonwealth adopted the federal ban on lead materials,” he added. “If we know a building was not built until after this date, we know that its private service line would not contain lead. In addition, our statistical analysis project allowed us to determine that structures built between 1950 and 1988 do not contain lead materials. We looked at over 400 service lines within this date range and found that there was no lead, which is enough to make a statistically valid assessment of structures within that range.”

For several decades, Louisville Water has been an industry leader in identifying and replacing lead lines in its system. In fact, we first launched a project to replace public lead service lines in the mid-1980s.

According to Dan Lambert, Louisville Water GIS Manager, “Information collected regarding these replacements included new service material used on the public side of the service lines but did not include collecting the customer’s private-side material types until the 2010s.”

Then, “an effort was made in 2018 to retroactively collect this information from previously submitted hardcopy documents into a database and ultimately into our GIS service data,” Lambert said. “Further analysis methods, including historic aerial imagery and GIS data review, were employed in 2021 in efforts to categorize and reduce the overall inventory of unknown private materials as defined by the EPA.”

The recent detective work was able to build on these earlier efforts, but it was still a daunting task because “we have never executed a data-gathering/analysis project of this magnitude before,” Basham said. “With many things we do, we have detailed work instructions for how to complete a task. With this project, we had to constantly ask ourselves if our methodologies were valid and defensible.”

He emphasized that “certain gaps in institutional data required significant creativity and innovation from our GIS Department. Additionally, we have had to refine work processes across the company to account for LCRR inventory requirements, including many of our longstanding GIS and planning processes.”

But Basham also detailed how the project not only met the EPA regulation but also will benefit Louisville Water and its customers.

“Our critical mission is public health,” he said. “We want to get rid of as much lead material in our community as possible, since lead service lines have the potential to leach lead into drinking water. The better our data is, the easier it is for us to target lead removal projects and know that we are on track towards our goal of getting all the lead out.”

*Louisville Water replaced about 74,000 known lead service lines that we installed decades ago. We are focused on helping customers identify lead service lines on their property. We’ve created a lookup tool on LouisvilleWater.com where customers can check our records using their Louisville Water account number.