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478 South Dakota water systems have inventoried 326,512 service lines for EPA. 2,081 (0.6%) are confirmed lead and 96,462 (30%) are still of unknown material. Below: every large or city-linked South Dakota utility ranked by lead lines.
South Dakota water systems reported 2,081 lead service lines and 616 galvanized lines requiring replacement as of Q2 2026 — 0.6% of the 326,512 lines inventoried and <0.1% of the national lead total, ranking #32 of 51. RAPID CITY reports the most in the state (106).
RAPID CITY (106), SIOUX FALLS (15).
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.
472 of the 478 South Dakota systems in EPA's Q2 2026 report have filed line counts. The 2,081 confirmed lead lines and 616 galvanized lines requiring replacement come from 61 systems — 13% of those reporting — so roughly one South Dakota system in 8 reports at least one lead line. 96,462 lines (30%) are still of unknown material, above the national share of 22%.
Treat "unknown" as the operative number. 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 South Dakota, that makes the 96,462 unknown lines (30%) the pool from which future confirmed-lead counts will be drawn.
To check your own line, start with your utility: most South Dakota 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 (2 shown). State totals above include every reporting system.
| # | Water system | Status | Lead | GRR | Unknown | Total lines | City report |
|---|---|---|---|---|---|---|---|
| 1 | RAPID CITY SD4600406 · 72,009 served | Lead service lines present | 106 | 199 | 1,194 | 23,451 | |
| 2 | SIOUX FALLS SD4600294 · 216,462 served | Lead service lines present | 15 | 21 | 18,038 | 63,726 |
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 South Dakota city water reports.
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