Keep an evidence-based inventory of the service lines connecting the regulated system to buildings, including the relevant system-owned and customer-owned portions. Preserve material classifications, supporting records and updates. The initial inventory deadline was October 2024; distinguish those continuing duties from the LCRI baseline inventory and other requirements due in November 2027.
Which system and compliance phase apply?
Confirm that the supply is a community or nontransient noncommunity public water system and identify its drinking-water authority. A privately owned business supply can meet that classification; the registration guide addresses that earlier decision. An ordinary household well is a different context.
The initial Lead and Copper Rule Revisions inventory deadline was October 16, 2024. That date has passed; it is not a new filing window. The federal transition provisions retain specified inventory and notification duties before November 1, 2027, when the Lead and Copper Rule Improvements baseline inventory and broader requirements apply, subject to their specific provisions. Arizona’s current R18-4-102 incorporates the July 1, 2025 federal codification, including effective-date notes. Ask the authority which submission and update instructions apply now.
What belongs in the material record?
EPA’s June 2023 small-system guide explains the initial inventory’s coverage: service lines connecting the main to building plumbing, including customer-owned portions and split ownership. Record the relevant portions accurately rather than stopping at the utility’s property boundary. A repair invoice for one short section may not identify the material along the remaining service.
Use the applicable categories and state instructions for lead, galvanized requiring replacement, non-lead and lead status unknown. Retain the evidence behind each classification. A galvanized line’s history can matter, and missing evidence should not silently become a non-lead finding. The guide describes an initial-inventory framework; confirm the expanded LCRI baseline requirements, including connector information, with the authority before treating the older template as complete for 2027.
How should uncertain entries be improved?
Organize construction records, earlier inventories, repair documentation and other accepted material evidence by the actual service location. Record what each source establishes and what remains unknown. Have qualified personnel arrange necessary field identification and utility coordination; this is not a homeowner excavation or pipe-scratching procedure.
Include material information discovered during suitable maintenance and replacement work in the update process. Preserve previous information and the basis for a changed classification so the responsible operator can explain it. A new section or meter does not automatically establish that the whole connection was replaced.
How is the inventory used without overstating it?
Coordinate required public accessibility and notices with the authority, including instructions for known or potential lead service lines. Keep the inventory, supporting evidence and related submissions consistent. An internal spreadsheet alone does not complete every required customer communication.
The inventory describes piping materials; it is not a test proving the water at a particular faucet is safe. Home lead testing and the community system’s consumer confidence report answer different questions. Likewise, Phoenix’s homeowner service-line replacement information is a local program context, not the inventory procedure for every Arizona supplier.