South Dakota tap water quality

510 active community water systems.

Largest water systems

GradeSystemPeopleHealth violations (5y)
ASioux Falls216,4620
ARapid City72,0090
DAberdeen27,9897
ABrookings Municipal Utilities23,3770
AWatertown Municipal Utilities23,2300
AWeb Water Development Association20,7500
AMitchell15,6510
AYankton15,4110
AHuron14,2630
APierre14,0910
DBox Elder14,0009
ASpearfish13,8030
AMinnehaha Community Water Corp13,4350
ABy Water District13,3200
AMid-Dakota Rural Water11,8330
AVermillion11,6950
ARapid Valley Sanitary District11,4080
ABrandon11,0480
AHarrisburg10,2970
AEllsworth AFB9,1000
APine Ridge Water System7,4820
ATea7,3810
ASturgis7,0200
AKyle Water System6,5260
AKingbrook I Rural Water System6,4550
ARandall Community Water District6,2480
ABrookings-Deuel Rural Water System6,2000
AMadison6,1910
ALincoln County Rural Water System5,9650
ABig Sioux Community Water System5,8000
ABrown-Day-Marshall RWS5,6730
ABelle Fourche5,6170
BSicangu Mni Wiconi Rural Water System5,6101
BRosebud Rural Water System5,5001
ASouth Lincoln Rural Water System5,2500
AWr/Lj - Mni Wiconi5,1850
AGrant-Roberts Rural Water System5,0500
ATripp County Water User District4,8600
AClay Rural Water System4,7800
ABlack Hawk Water User District4,5000
ASioux Rural Water System4,2800
ATm Rural Water District4,2500
BEagle Butte4,0001
ADakota Dunes Cid3,7000
ADell Rapids3,6330
AOglala RWS Pipeline3,5620
AMilbank3,5440
ADavison Rural Water System Inc3,4850
AHartford3,3960
AHot Springs3,3950

Most issues (systems serving 10,000+)

D

Aberdeen

Serves 27,989 people · Surface water · Full report →
7 health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
D

Box Elder

Serves 14,000 people · Groundwater · Full report →
9 health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
A

Brandon

Serves 11,048 people · Groundwater · Full report →
No health-based violations in the last 5 years; 2 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
A

Mitchell

Serves 15,651 people · Surface water · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Sioux Falls

Serves 216,462 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Rapid City

Serves 72,009 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Brookings Municipal Utilities

Serves 23,377 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
A

Watertown Municipal Utilities

Serves 23,230 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Web Water Development Association

Serves 20,750 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Yankton

Serves 15,411 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Huron

Serves 14,263 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
A

Pierre

Serves 14,091 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
A

Spearfish

Serves 13,803 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Minnehaha Community Water Corp

Serves 13,435 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

By Water District

Serves 13,320 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Mid-Dakota Rural Water

Serves 11,833 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Vermillion

Serves 11,695 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Rapid Valley Sanitary District

Serves 11,408 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Harrisburg

Serves 10,297 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).

Cities

AberdeenAgarAkaskaAladdinAlcesterAlexandriaAllenAlpenaAmherstAndoverArlingtonArmourArtesianAshtonAstoriaAtkinsonAuroraAvonBadgerBalticBarnardBateslandBathBelle FourcheBeresfordBig Stone CityBillingsBisonBlack HawkBlackhawkBluntBonesteelBowdleBox ElderBradleyBrandonBrandtBrentfordBridgewaterBristolBrittonBrookingsBruceBryantBuffaloBuffalo GapBurbankBurkeCandoCanistotaCanovaCantonCaputaCarpenterCarthageCastlewoodCavourCedaredgeCentervilleChamberlainChancellorCherry CreekChesterClaire CityClaremontClarkClear LakeColmanColomeColtonColumbiaCondeCoronaCorsicaCresbardCrooksCusterDakota DunesDallasDanteDavisDe SmetDeadwoodDel MarDell RapidsDelmontDimockDolandDraperDupreeEagle ButteEdenEdgemontEganElk PointElktonEllsworth AFBEmeryErwinEstellineEthanEurekaExcelsiorFairburnFairfaxFairviewFaithFaulktonFedoraFerneyFlandreauFlorenceFlower MoundFort MeadeFort PierreFort ThompsonFrankfortFrederickFreemanFruitdaleFultonGann ValleyGarden CityGarretsonGaryGayvilleGeddesGettysburgGlencrossGlenhamGoodwinGregoryGrenvilleGrotonHamillHarrisburgHarrisonHarroldHartfordHaytiHazelHeclaHenryHermosaHerreidHerrickHighmoreHill CityHitchcockHolabirdHosmerHot SpringsHoughtonHovenHowardHowesHudsonHumboldtHurleyHuronIdealInteriorIpswichIreneIroquoisIsabelJavaJeffersonKadokaKaylorKennebecKeystoneKimballKranzburgKyleLaboltLake AndesLake CityLake NordenLake PrestonLaneLangfordLantryLeadLebanonLemmonLennoxLeolaLestervilleLetcherLodgepoleLong LakeLower BruleLuverneLyonsMadisonMandersonMansfieldMarionMartinMartyMarvinMc IntoshMc LaughlinMcIntoshMcLaughlinMeadowMelletteMennoMercer IslandMidlandMilbankMillerMinaMissionMission HillMitchellMobridgeMonroeMontroseMorristownMound CityMount VernonMurdoNew EffingtonNew HollandNew UnderwoodNewellNislandNorrisNorth Sioux CityNorthvilleNundaOacomaOelrichsOglalaOkreekOldhamOlivetOnakaOnidaOralOrientOwankaParkerParkstonParmeleePeeverPhilipPickstownPiedmontPierpontPierrePine RidgePlankintonPlattePollockPrairie CityPreshoPringlePukwanaQuinnRamonaRapid CityRaymondRedfieldRee HeightsRelianceRennerRevilloRidgeviewRockhamRoscoeRosebudRosholtRoslynRutlandSaint CharlesSaint FrancisSaint LawrenceSaint OngeSalemScotlandScrantonSelbySenecaSinaiSioux FallsSissetonSmithwickSouth ShoreSpearfishSpencerSpokaneSpringfieldSt OngeStephanStickneyStockholmStrandburgStratfordStrugisSturgisSummersetSummitTaborTeaTimber LakeTolstoyTorontoTrail CityTrentTrippTualatinTulareTurtonTwin BrooksTyndallUticaValeValley SpringsVeblenVermillionViborgViennaVirgilVolgaVolinWagnerWakondaWallWallaceWanbleeWardWarnerWastaWatertownWaubayWebsterWellesleyWentworthWessingtonWessington SpringsWestminsterWestportWhiteWhite LakeWhite RiverWhitehorseWhitewoodWillow LakeWilmotWinfredWinnerWittenWolseyWoodWoonsocketWorthingWounded KneeYaleYankton