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5 District of Columbia water systems have inventoried 138,406 service lines for EPA. 16,935 (12%) are confirmed lead and 13,428 (9.7%) are still of unknown material. Below: every large or city-linked District of Columbia utility ranked by lead lines.
District of Columbia water systems reported 16,935 lead service lines and 225 galvanized lines requiring replacement as of Q2 2026 — 12% of the 138,406 lines inventoried and 0.8% of the national lead total, ranking #18 of 51. D.C. WATER AND SEWER AUTHORITY reports the most in the state (16,935).
D.C. WATER AND SEWER AUTHORITY (16,935).
Find your utility in the table below, then check its published service line inventory (most utilities post an address-lookup map) or call the number on your water bill. Utilities must notify customers whose line is lead, galvanized-requiring-replacement or unknown. You can also test the pipe entering your home: lead is soft, dull gray, non-magnetic and turns shiny when scratched.
Under EPA's Lead and Copper Rule Improvements, systems must replace lead and galvanized-requiring-replacement lines within 10 years starting in 2027; systems with very high counts can receive longer deadlines. Ask your utility for its replacement plan and whether it covers the homeowner-owned portion.
Use a filter certified to NSF/ANSI 53 for lead for drinking and cooking, flush the tap after water has sat for hours, never use hot tap water for drinking or infant formula, and confirm your actual level with a certified lab test.
Source: EPA SDWIS Service Line Inventory, Q2 2026 snapshot (updated 2026-08-18). Counts are service lines, not people.
5 of the 5 District of Columbia systems in EPA's Q2 2026 report have filed line counts. The 16,935 confirmed lead lines and 225 galvanized lines requiring replacement come from 1 system — 20% of those reporting — so roughly one District of Columbia system in 5 reports at least one lead line. 13,428 lines (9.7%) are still of unknown material, below the national share of 22%.
Why unknown lines matter: Under EPA's Lead and Copper Rule Revisions (LCRR), every community water system had to submit an initial service line inventory by October 16, 2024, and lines whose material could not be documented were reported as unknown. The Lead and Copper Rule Improvements (LCRI), finalized in October 2024, require systems to keep identifying those lines, to notify customers served by a lead, galvanized-requiring-replacement or unknown line, and to replace lead and galvanized-requiring-replacement lines — generally within 10 years of the rule's November 1, 2027 compliance date. The LCRI also lowers the lead action level from 15 to 10 ppb. For District of Columbia, that makes the 13,428 unknown lines (9.7%) the pool from which future confirmed-lead counts will be drawn.
To check your own line, start with your utility: most District of Columbia systems publish their inventory as an address-lookup map or table, and the annual Consumer Confidence Report (CCR) names the system and its lead results. If your address shows lead, galvanized or unknown, the utility is required to have notified you; if you cannot find it, ask for the service line material on record. You can also inspect the pipe where it enters the house — lead is dull gray, soft enough to scratch shiny with a coin, and does not attract a magnet.
EPA's rule text and timelines are on its Lead and Copper Rule Improvements page. While your line is unverified, our best water filters for lead guide covers NSF/ANSI 53-certified options, and the lead in drinking water guide explains testing and health thresholds.
EPA SDWIS Service Line Inventory, Q2 2026 snapshot (updated 2026-08-18); regulatory dates from EPA's LCRR/LCRI pages.
Community systems serving 50,000+ people plus systems linked to a city report on this site (1 shown). State totals above include every reporting system.
| # | Water system | Status | Lead | GRR | Unknown | Total lines | City report |
|---|---|---|---|---|---|---|---|
| 1 | D.C. WATER AND SEWER AUTHORITY DC0000002 · 632,323 served | Lead service lines present | 16,935 | 190 | 13,388 | 137,166 |
A lead or unknown service line means lead can enter water after it leaves the treatment plant, so city-level test results understate what reaches your tap. Filter drinking and cooking water with an NSF/ANSI 53 lead-certified system, and see the lead in drinking water guide or District of Columbia city water reports.
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