Lead Service Line Inventory Information
For Minnesota Public Water Systems

Understanding the rule

All Public Water Systems must complete and submit to the state a lead service line inventory by October 16, 2024.

The Lead and Copper Rule Revisions require public water systems to identify the service line materials of all service connections in their distribution system regardless of ownership status. The rule determines the minimum information required to be needed in your lead service line (LSL) inventory, how to communicate about your system inventory, and how often to update the inventory. It may be more useful to the system while conducting their inventory to gather additional or more detailed information than required.

The Safe Drinking Water Act Lead and Copper Rule (LCR) along with the Lead and Copper Rule Revisions (LCRR) can be found at Code of Federal Regulations (title-40/part-141/subpart-I)  and the lead service line inventory requirements can be found at Code of Federal Regulations (title-40/section-141.84. EPA has LCRR guidance for developing inventories, including a template that can be found at Revised Lead and Copper Rule.

This page details the steps that Community Water Systems (CWS) should take to develop their inventories. MDH will be working with Non-Transient and Noncommunity Water Systems (NTNCWS) directly to assist with inventory development.

Creating your lead service line inventory

Step 1: Gather your data

You will need to find out the materials of the service line for both the publicly controlled and privately controlled portions of the service line, even if the line is completely privately owed.  First, look at the information you do have and identify what is still unknown. Then prioritize how you will reduce the number of unknowns. Sources of information may include:

Historical records

• Utility records, local plumbing codes that identify year of lead ban adopted before 1986 federal ban.
• Ordinances related to discontinuing lead in service line installations.
• Distribution system maps and drawings (as builts).
• Building year and construction records with respect to the lead ban.
• Tap/tie cards with connection year.
• Plans from water main installation, rehabilitation, and/or replacement.
• Plumbing permits and permit amendments.

Customer-driven data

• Information provided by customers, such as personal historical records.
• Construction year and records, and plans and drawings.
• Previous service/repair reports.
• Information from homeowner insurance.
• Inspection reports, photo documentation of materials used inside the building.
• LSL replacement documentation (e.g., plumber invoice or plans and drawings from rebuilding).
• Information obtained at the request of the water system, such as a survey or scratch and magnet tests or photos.

Sampling

• Alternative sampling protocols—e.g., sequential or profile sampling, short or long stagnation, random day–time sampling (expertise needed). Typical parameters to analyze include lead, copper, pH, alkalinity, iron, cadmium, zinc, tin, and temperature.
• Scratch and magnet tests.
  • Scratch test: use of a key, coin, or other sharp metal object to scratch the outer surface of the pipe—lead is easy to scratch and leaves a silver and shiny surface underneath.
  • Magnet test: magnets stick to galvanized or iron pipes but not to lead or copper pipes.
• Closed-circuit television inspection and camera scoping.
• Inspection of the pipe interior using a fiber-optic camera inserted inside the service line.
• Predictive modeling and machine learning (pending guidance from EPA).
• Geospatial approach to predict the likelihood that a residence has an LSL on the basis of neighboring field data (i.e., house inspection) and secondary information (i.e., construction year and city records).
• Potholing, vacuum excavation, and hydro-excavation.
  • Potholing: digging a hole to expose a segment of the service line using a backhoe or hand tools.
  • Vacuum excavation: using high-velocity, high-pressure air to break up the soil to create a hole to expose a segment of the service line.
  • Hydro-excavation: using high-velocity, high-pressure water to break up the soil to create a hole to expose a segment of the service line.
• Visual inspection.
• Curb box inspection.
• Point of entry, in home/premise plumbing (by water system).
• Meter pit inspection.

Technical Guidance Details

The EPA released Guidance for Developing and Maintaining Service Line Inventories to support water systems in their efforts to develop inventories and to provide states with needed information to provide oversight and reporting to EPA. The guidance is available to view on the EPA Revised Lead and Copper Rule (PDF). MDH will be putting together a comprehensive summary of the EPA technical guidance, state specific approaches to inventory development and answers to questions asked by MN systems.

Step 2: Consolidate your data into an electronic database

Public water systems should have the ability to make data accessible to the public and to the department of health in a consistent electronic format such as a database or spreadsheet. The minimum fields required are:

• Location identifier such as address or GIS coordinates.
• Material type of privately owned side (lead, non-lead, galvanized in need of replacement, unknown).
• Material type of publicly owned side (lead, non-lead, galvanized in need of replacement, unknown).
• Source of information used to determine material type (type of record, inspection, etc.).

Learn more about service line material types: Service Line Material Types and Definitions.

Step 3: Prioritize and keep your inventory up-to-date

Many systems will have unknowns in their initial inventory. That’s ok, once you know what you don’t know you can create a plan for determining the missing information.

• At minimum your inventory needs to be updated at the same frequency as your lead and copper sample schedule, at most on an annual basis. For systems on a three-year monitoring, you may want to update the inventory annually or in real-time with projects and renovations to keep customers informed.

• How to prioritize determining unknown services lines: based on factors including but not limited to the targeting of areas with known lead service lines, service lines which serve disadvantaged consumers and/or populations most sensitive to the effects of lead.

Notifications and communicating with customers about LSLI - no lead service line inventory

Keeping customers informed about the importance of the inventory to reducing lead exposure may encourage customers to participate in the inventory and replacement process.

Required : After the inventory process:

All water systems with lead, galvanized requiring replacement, or lead status unknown service lines in their inventory must inform all persons served by the water system at the service connection with a lead, galvanized requiring replacement, or lead status unknown service line.

A water system must provide the initial notification within 30 days of completion of the lead service line inventory required under the LCRR and repeat the notification on an annual basis until the entire service connection is no longer a lead, galvanized requiring replacement, or lead status unknown service line. For new customers, water systems shall also provide the notice at the time of service initiation.

Types of Communications about Lead Service Lines

• Consumer Confidence Report: in addition to the information about reducing lead exposure from drinking water, systems will need to include information on how to access information about the lead service line inventory. MDH will provide template information in your CCR Draft each year.
• Annual notification: Customers served by a lead service line or galvanized line in need of replacement will need to be notified annually about the health risks, and steps they can take to reduce exposure. MDH provides template language for systems in the consumer confidence reports.
• New services: Water systems must provide notice to customers at the time of service initiation if they are served by a lead service line, galvanized in need or replacement, or lead status unknown service line.
• Infrastructure Tracking Tool: This is an online tool developed in partnership with the University of Minnesota to provide one location for inventories across the state. This will allow all systems the ability to put their inventories on the web so customers can search by address to see if there is a lead service line. This will meet the requirement for systems with population >50,000 to make their inventories available on a webpage.

Special cases: Systems with no lead service line, no galvanized in need of replacement and no unknowns

Systems in this situation must be able to document their status. Water systems whose inventories contain only non-lead service lines are not required to provide inventory updates to the State or to the public. These systems will have reduced notification requirements to customers such as only including a line in their annual CCR declaring that it only has non-lead services and provide a basis for that determination.

If, in the future, such a water system finds a lead service line or galvanized in need of replacement within its system, it must prepare an updated inventory and follow requirements for updating its inventory and conducting customer communication.

Templates and tools

Other MDH Resources for Lead in Drinking Water

• Lead in Drinking Water
• Lead and Copper Rule Revisions
• Drinking Water Revolving Fund General Information
• MDH Quick Reference Guide for Lead Service Line Inventories (PDF)
• Service Line Classification Determination: Systems with Shared Ownership (PDF)

External Resources

• EPA Resources
  • Guidance for Developing and Maintaining a Service Line Inventory (PDF)
  • Inventory Template (Excel)
• Lead Service Line Collaborative
  • Getting Started on an LSL Inventory
  • Communicating about Lead Service Lines
• American Water Works Association
  • Lead Communications

Return to Lead and Copper Rule Revisions

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