Insights

From the 2024 initial inventory to the 2027 baseline inventory

Published October 13, 2026 · Lead Inventory Desk

If your system sent the state an initial inventory in 2024, you are not done. The 2024 rule asks for an updated "baseline inventory" by November 1, 2027, and it asks for more than the first one did.

What the 2024 initial inventory covered

Under the 2021 rule, every community and non-transient non-community water system had to develop an initial inventory by October 16, 2024. It had to include every service line, whoever owned it, put each line in one of four categories (lead, galvanized requiring replacement, non-lead, or lead status unknown), and be made publicly accessible. The state received counts of lead, galvanized requiring replacement and unknown lines (40 CFR 141.84(a)(1) and 141.90(e)(1)).

Not every system made that deadline. EPA's 2024 compliance report counted 3,902 public water systems with a health-based violation for missing it. In EPA's records today, 4,574 community systems serving 10,000 or fewer carry that violation (code 2E), and 1,544 of them are still listed as in violation (our snapshot).

What the 2027 baseline inventory adds

1. Connectors. The baseline must list every connector you identify, the short bendable piece of up to three feet, often called a gooseneck or pigtail, that usually joins the service line to the main. Each one is "Lead", "Non-Lead", "Unknown" or "No connector present" (40 CFR 141.2 and 141.84(a)(2)). In 2024 EPA only recommended listing lead connectors where data were available.
2. A street address for every line and connector. Where there is no address, a block, GPS point, intersection or landmark will do (40 CFR 141.84(a)(4)). EPA notes that, starting with the baseline inventory, the public version must include these addresses.
3. Everything you have learned since 2024. New records, meter replacements, repairs and any field checks go in (40 CFR 141.84(a)(2)(iii)).
4. New totals for the state. Counts of lead, galvanized requiring replacement, unknown and non-lead lines, plus lead connectors and connectors of unknown material, counting each full line once (40 CFR 141.90(e)(2)).

What arrives with it

A replacement plan. If the baseline shows even one lead, galvanized requiring replacement or unknown line, a service line replacement plan is due on the same day. It covers how you will identify unknown lines, how and in what order you will replace lines, funding, communications, flushing and access to private property (40 CFR 141.84(c)). It was not among the 2021 rule requirements that took effect on October 16, 2024; EPA lists those as the initial inventory, the customer notices and public notice of a lead action level exceedance.

Notices on a new clock. People served by a lead, galvanized requiring replacement or unknown line get a notice within 30 days of the baseline inventory, then within 30 days of each yearly update deadline (40 CFR 141.85(e)(2)).

Yearly updates. From January 30, 2029, and every January 30 after, the state gets an updated inventory and either an updated plan or a statement that nothing changed (40 CFR 141.90(e)(3) and (e)(4)). Systems whose inventory shows only non-lead lines and no lead or unknown connectors are spared the yearly updates and may publish a short written statement instead of the full public inventory (40 CFR 141.84(a)(6) and (b)(1)(ii)).

A check on your non-lead lines. By December 31, 2034 for most systems, you must inspect a random sample of lines marked non-lead at two points, unless records show they were installed after the lead ban, they were already inspected at two points, or they replaced a lead line (40 CFR 141.84(b)(5)).

Public access, spelled out. Systems serving more than 50,000 people must post the inventory and plan online. Smaller systems can use another method, such as a copy at the office or by mail, and the Consumer Confidence Report must say how to find the inventory (40 CFR 141.84(a)(5) and (c)(2); EPA fact sheet).

Three questions to ask now

1. Did our state accept our 2024 inventory, and is anything open on our federal record?
2. Which template does our state want for the baseline, and which identification methods will it accept?
3. How many of our lines and connectors are still unknown, and which records could settle them?

About the court case: the 2024 rule is being challenged in the D.C. Circuit (American Water Works Association v. EPA, No. 24-1376), argued September 30, 2026. As of this article's date, the rule is in effect and its dates stand, and the inventory duty also exists under the 2021 rule.