Skip to Main Content
CDM Smith logo
CDM Smith Site Logo
Project background not configured

Practices

Drinking WaterConstruction Management

Markets

Municipal UtilitiesLocal, County, and State Government

Priorities

Lead in Drinking Water

The Lead and Copper Rule Revisions (LCRR) required all water systems to submit an initial inventory of lead service lines (LSLs) by October 16, 2024 to their primacy agency, including all those service lines connected to the public water system. The Lead and Copper Rule Improvements (LCRI) require a "baseline" inventory of service lines and connectors no later than November 1, 2027, a validation pool for non-lead services, and the biggest change that we've seen: all public water systems will have 10 years to identify unknowns and replace all LSLs and galvanized requiring replacement (GRR) service lines.

In August 2025, EPA announced it will defend the Biden administration’s LCRI against AWWA’s lawsuit, while also “developing new tools and information to support practical implementation flexibilities and provide regulatory clarity.” More information on what that could mean for your utility here.

Defining a service line

To effectively compile inventories it's crucial to understand how the EPA defines a service line: it's the pipe that connects the water main to the building inlet or, if there's no building, to the outlet. But what does that mean exactly? The EPA doesn't give a clear definition of the building inlet, so different utilities have different ways of deciding where it is. Some say it's the first fitting inside the building foundation, some say it's the point at which the service line penetrates the building, and some say it's the water meter when located inside the building.

The definition of an outlet is also ambiguous, but when we look at the regulations, we see that the word outlet is always used alongside the words “for cooking and drinking” or “for human consumption." So that's what we use as our guide. If there's no building and we're trying to figure out if it's a service line, we ask ourselves, does it connect a water main to an outlet? Could the outlet be used for cooking or drinking? And if we say yes, then we classify it as a service line.

 

Creating your inventory and compiling service line info

To follow the rules for LCRR/LCRI compliance, utilities need to keep a compre­hen­sive record of all their service lines. Utilities must create a detailed database of all service lines, integrating data from different sources like tap cards, meter and billing records, and capital project records. Sometimes this data may not match up, so we have to figure out which source is the most trustworthy to establish a hierarchy of reliability. Each service line needs to be recorded with a unique name or number, so they aren't mixed up, especially when there are many units in one building.

Having a clear understanding of the definition of a service line is honestly the most important part of creating an inventory and compiling your information.

Danielle Liu, envi­ron­men­tal engineer


Maintaining and updating your inventory

Utilities are required to update inventories annually for regulatory reporting. This involves identifying material clas­si­fi­ca­tion of each portion of the service line, such as copper or lead, and determining the service line material clas­si­fi­ca­tion of the entire service line, such as non-lead, lead, or GRR.

A huge aspect of this clas­si­fi­ca­tion process is under­stand­ing the historical context of each portion of the service line. For example, a galvanized pipe downstream of a previous LSL must be replaced due to the potential of lead scale buildup on the inside of the galvanized pipe. This requires keeping accurate records of previous pipe materials and replace­ments to ensure accurate clas­si­fi­ca­tion. Some examples for classifying the entire service line, if your state is following the EPA’s guidance for clas­si­fi­ca­tion, are:

Non-lead: If the system-owned material is plastic or copper and was never lead, even if the customer-side material is galvanized, it can be classified as non-lead on the EPA’s inventory template. This is true for most utilities, but some states require galvanized service lines to be classified as GRR regardless of the upstream pipe material. Check with your state to see what is required of your utility.

GRR: If the system-owned material is plastic or copper and there is no record of the original instal­la­tion material, and the customer-side material is galvanized, it must be classified as GRR due to the uncertainty of potential lead cont­a­m­i­na­tion.

 

Documenting other potential sources of lead

Construction worker in safety gear jotting down notes near a road with traffic cones and no parking sign.

It’s important to record other potential sources of lead observed during inspections, such as lead or galvanized pipes in premise plumbing. Premise plumbing can be a potential source of lead, even if outside the limits of the service line, and this crucial information for overall lead risk management should be documented.

Practices

Drinking WaterConstruction Management

Markets

Municipal UtilitiesLocal, County, and State Government

Priorities

Lead in Drinking Water

Curious to learn more?

When you're ready to apply this thinking, our experts can help. 

Carolyn Loudermilk

Carolyn Loudermilk

Environmental Engineer

Carolyn specializes in wastewater treatment, conveyance and water distribution, preparing plans and bid documents for WTPs, WWTPs and pumping stations.

Danielle Liu

Danielle Liu, PE

Environmental Engineer

Danielle has experience in wastewater and drinking water treatment, water quality analyses, PFAS piloting and lead service line replacement.

More resources on this topic

View All Insights
Two construction workers in safety vests and helmets inspect a road excavation surrounded by orange cones.
Insight

Preparing for non-lead validation under the LCRI should start now

Every water system will need to validate their non-lead service lines or obtain a waiver under the LCRI. Here's why the time to plan your validation study is right now.
Read More
Child's hand near a water fountain with water flowing, indoors.
Insight

School and child care sampling: LCRI requirements

What do water systems need to know about lead testing in schools and child care facilities under the LCRI? We asked environmental health expert Davida Judelson, MPH, to break it down.
Read More
A woman working at a desk with dual monitors displaying charts and diagrams in an office environment.
Insight

Find lead faster: shrinking LCRI replacement lists with data-driven tactics

Katie Deheer, data science expert at Trinnex, explains how data-driven strategies help utilities reduce uncertainty and plan more realistic, defensible replacements to comply with the LCRI.
Read More
Glowing digital envelopes on a dark background, symbolizing email communication.

Sign up for Lead and Copper Rule updates and more

Sign up for our newsletter to stay in the know on regulations, recent projects and the latest innovations to tackle lead in drinking water.

Sign Up
CDM Smith logo

Let’s Build Something Together

Have a project in mind or want to stay in the loop? Reach out to our team or subscribe to get the latest updates from our work.
Contact UsSubscribe

World Headquarters

75 State Street
Suite 701
Boston, MA 02109 USA
What We Do
  • Markets
  • Practices
  • Priorities
  • Projects
  • Innovation and Technologies
Who We Are
  • About Us
  • Careers
  • Cultural Threads Blog
  • Find Us
  • News
Resources
  • Insights
  • Subcontracting
  • Webinars
  • Legal & Terms of Use
  • Privacy Statement
  • Accommodation Request
  • California Privacy Rights
  • Contract Vehicles
CDM Smith™ | CDM™ | WILBUR SMITH™
© 2026 CDM Smith. All rights reserved.