EPA data · all 50 states + D.C. · July 2026
Is your water healthy?
Type your ZIP code and get a letter grade for your tap water — built from EPA violation records, not marketing. Then see exactly what's in it and what a filter can fix.
Check your tap water — enter your ZIP code or city
Grades come from EPA Safe Drinking Water records. We never see or store what you type.
C+Fair
America's tap water earns a C+
Across all 50 states and D.C., U.S. tap water rates C+ (fair) on our scale — a blend of EPA contaminant-compliance scores and health-based violation rates. It's broadly safe, but the spread is wide: your state, and especially your city, can land a full letter grade above or below. How we grade →
Best and worst states for tap water
Top of the class
- HawaiiA+Excellent
- New HampshireAExcellent
- South DakotaA-Excellent
- North CarolinaA-Excellent
- IndianaB+Good
Needs a filter
- OklahomaDPoor
- NevadaDPoor
- Rhode IslandDPoor
- ArkansasC-Fair
- TexasC-Fair
Explore the data
The spread at a glance: water hardness
AR 38 PPMMA 50 PPMHI 60 PPMME 60 PPMNH 60 PPMMS 70 PPMOR 70 PPMVT 70 PPMWA 70 PPMCT 75 PPMNY 75 PPMRI 75 PPMMT 95 PPMAK 100 PPMID 100 PPMLA 100 PPMNJ 100 PPMKY 112 PPMMD 118 PPMIL 120 PPMNC 120 PPMPA 120 PPMVA 120 PPMGA 130 PPMIA 130 PPMND 130 PPMOH 130 PPMSC 130 PPMTN 130 PPMWV 130 PPMDC 135 PPMMI 140 PPMWI 140 PPMAL 150 PPMSD 150 PPMMN 175 PPMCO 185 PPMCA 200 PPMDE 200 PPMFL 200 PPMMO 200 PPMNE 210 PPMOK 210 PPMWY 210 PPMKS 250 PPMNM 252 PPMUT 259 PPMTX 268 PPMAZ 280 PPMIN 298 PPMNV 300 PPM
Arkansas 38 PPMNevada 300 PPM
Softest water: five states
- Arkansas38 PPM
- Massachusetts50 PPM
- Hawaii60 PPM
- Maine60 PPM
- New Hampshire60 PPM