EPA's Lead and Copper Rule Improvements (LCRI) require utilities to identify all water service line materials, including those downstream of master meters. A master meter is a single water meter that provides service to multiple buildings or units on a shared property. They are common in apartment buildings, mobile home parks, college campuses, gated communities, and commercial developments. Once water passes through the master meter, it travels through privately owned mains and service lines to reach individual buildings or units. In many cases, utilities have no visibility or control over the mains and service lines beyond the meter.
To comply with evolving Lead and Copper Rule regulations, how can utilities begin to identify service line materials downstream of master meters where record information is unknown? These situations typically fall outside of the traditional utility ownership and control, but they are still the water system’s responsibility for listing in the inventory.
The figure above outlines the EPA’s interpretation of one type of master meter configuration and the pipe sections to be included in an inventory. The EPA’s Inventory June 2023 Guide states that a community water system inventory must include “all service lines connecting the water main to the interior plumbing in a building, regardless of the actual or intended use." These include, for example, service lines connecting multiple units or buildings on a property.
In addition to including in the inventory, the EPA’s LCRI states that all Community Water Systems (CWSs) and Non-Transient Non-Community Water Systems (NTNCWSs) must make a “reasonable effort” to replace any lead or galvanized requiring replacement (GRR) service lines, even if they are beyond a master meter.
What do master meter scenarios look like?
One-to-many service line configuration
A utility-owned service line feeds through a master meter and then branches into multiple privately owned service lines to individual homes or units. This configuration is common in trailer parks or garden apartment complexes.
Responsibility: The utility must inventory and eventually replace (if needed) each service line to every building.
Private community distribution system
A master meter feeds a privately owned water main that serves multiple buildings with private service lines connecting from that main to each building. The entire internal network is privately owned. This configuration is common in campus-style developments.
Responsibility: The LCRI and the guidance documents do not indicate that a water main must be owned by the water system, but the utility still has to inventory the service lines up to each building inlet. The EPA states that the pipe connecting the water main to the building must be inventoried no matter how the ownership is divided. In the above graphic, this would be C1, C2 and C3.

