Tap water quality in South Dakota

South Dakota scores 96.5/100 in TapWaterData's 2026 population-weighted analysis of EPA violation records — rank #6 of 51 (1 = best). Its community water systems averaged 1.1 health-based violations each in 2024, versus a 2.5 U.S. average. Individual utilities vary widely; check your utility's Consumer Confidence Report for your exact system.

The score reflects contaminants that exceeded EPA limits or health guidelines somewhere in the state — most commonly bacteria (coliform), disinfection byproducts, nitrates in agricultural areas, and lead from old service lines. Below-average violations per system is a good sign, but small rural systems and private wells still warrant testing. EPA's new PFAS limits (finalized 2024) are also starting to appear in utility reports.

Every community water system must publish an annual Consumer Confidence Report (CCR) — search your utility's name plus 'water quality report,' or find it through EPA's CCR search. If you're on a private well, no one tests it but you: a certified lab test ($50–$200 per Angi) covering bacteria, nitrates and metals is the standard recommendation.

The right filter for the right contaminant does: certified reverse osmosis removes most dissolved contaminants including lead, nitrates and PFAS at the tap ($150–$1,300 installed per Angi 2026); activated carbon handles taste, odor and disinfection byproducts. Look for NSF/ANSI certification for the specific contaminant, and test first so you're treating what's actually there — our purification calculator walks through it.