Division of Drinking Water

Step by Step Guidance – Lead Service Line Inventory

Follow the directions to complete your water system’s lead service line inventory.

Baseline Inventory is coming up November 1, 2027

What is the initial inventory?

The Initial Service Line Inventory is something that all Community and Non-Transient Non-Community Systems had to complete by Oct. 16 of 2024. Every service line in your system, both the utility side and the customer side, needs to be identified within four categories: lead, non-lead, galvanized requiring replacement (GRR), or unknown. You are not expected to find out every single line when you submit your initial inventory. However, finding out as much as you can now is in your best interest.

What is the baseline inventory?

The Baseline Inventory builds on the initial inventory by adding two key components:

  • A detailed inventory of connector materials.
  • A two-point field verification process for service line materials identified through field verification.

This comprehensive Baseline Inventory is required to be completed and submitted by November 1, 2027.

How to complete the inventory

We do not expect all water systems to follow this method. If you would like to complete your inventory with a different method, you may submit your method proposal for DDW review and approval.

Before you start:

1

Determine if your water system is a Community or Non-Transient Non-Community (NTNC) System (Transient Non-Community systems do not need to comply with this requirement).

2

Then decide if your water system wants to participate in either funding program provided by the state. See Funding opportunities on the main page.

3

Download the inventory template and follow along to complete your inventory.

Step-by-step overview

Step 1

Perform a records review (customer side and utility side)

Complete the Minimum Service Line Material Verification (MSLMV) process to determine which service lines need field verification

Step 2.1 : Identify all known service lines

A system may avoid the Initial Predictive Modeling Process if all potable water service lines within the system meet the strict definition of “known.” Go to Step 5 if all your service lines are defined as “known.”

Step 2.2 & 2.3 : Identify all the service lines that need physical verification

Step 2.4 : Conduct verification using an approved method

Step 2.5 :  Record the results of the verification

Assess the reliability of the records

Classify material type of remaining unknown service lines

  1. No GRR or Lead found in records review or MSLMV Process
  2. GRR or Lead found in records review or MSLMV process
Step 5

Assess the reliability of the records

Submit either a completed non-lead form or initial lead inventory template.

Detailed steps

Screenshot of a the document: Lead Service Line Inventory Guidance

Full guidance document

For even more details than what are listed here, reference the Lead Service Line Inventory Guidance