Lead and Copper Rule

ETWD has completed the Lead Service Line Inventory (LSLI) required by U.S. EPA’s Lead and Copper Rule Revisions deadline of October 16, 2024. Through completing a historical records review and field investigations, ETWD has determined it has no lead or galvanized requiring replacement service lines in its distribution system. This includes any privately owned or customer owned service lines.

ETWD reviewed all applicable sources of information, including:

•   Available plumbing codes ranging from 1940-2024 to assess historical regulation of lead service lines locally (e.g. National Lead Ban, State Codes, County Codes, the Codes and Standards of the incorporated cities before the statewide lead ban in 1986)  
• Water system records which indicate the service line materials, customer data, tract maps, historical capital improvement or master plans, and standard operating procedures including the Laguna Hills Water Company 1980 service line installation standards  
• Water distribution system records which indicate the service line materials, GIS data, distribution system maps and drawings, as builts, historical lead and copper tap sampling results from 1999-2020, meter installation records, work orders, inspections conducted during the course of normal operations

In addition to reviewing the above sources of information, ETWD used an alternative method to develop the LSLI that was approved by the State Water Resources Control Board Division of Drinking Water on a case by case basis.

ETWD used indirect interpolation and stratified random sampling approaches to develop the LSLI. Both approaches involve physically inspecting a representative subset of service lines to confirm non lead materials, with the indirect interpolation approach being more suitable for homogeneous communities. The subset is stratified or divided into groups based on certain characteristics (e.g., years the service lines were installed). Stratification allows for a sample or subset of service lines to be more representative of the service lines in the distribution system.

After investigating the subset of service lines, if no lead or galvanized requiring replacement service lines are discovered, the remaining service lines may be assumed non lead with a certain level of confidence. ETWD inspected 1,434 service lines on the utility side and 1,043 service lines on both sides, and the service lines were inspected to be non lead. No lead or galvanized requiring replacement service lines were identified.

ETWD intends to document service line material information obtained from normal operations, such as service line or water meter maintenance, after October 2024 and will update the LSLI accordingly.