10,000+ reports checkedCheck hardness →
HARDNESS · MG/L AS CACO₃
Hardest tap water in America
Hard water is mostly a nuisance and appliance issue (scale, soap, water heaters) — not the same as PFAS or lead safety. Rankings use Consumer Confidence Report values where we have them, otherwise averages from EPA UCMR5 hardness fields on tracked city PWSIDs.
TOP 20 STATES (AVERAGE HARDNESS)
1.Arizona9 cities sampled
242.9 mg/L · Very hard2.New Mexico1 cities sampled
111 mg/L · Moderately hard3.Colorado5 cities sampled
78.6 mg/L · Moderately hard4.Utah2 cities sampled
71 mg/L · Moderately hard5.Nevada3 cities sampled
59 mg/L · Soft6.Texas11 cities sampled
43.7 mg/L · Soft7.Kansas1 cities sampled
41.5 mg/L · Soft8.California9 cities sampled
38 mg/L · Soft9.Pennsylvania1 cities sampled
37 mg/L · Soft10.Florida2 cities sampled
36.5 mg/L · Soft11.New Jersey2 cities sampled
36.1 mg/L · Soft12.South Dakota1 cities sampled
33.7 mg/L · Soft13.Nebraska2 cities sampled
27.3 mg/L · Soft14.Idaho1 cities sampled
24 mg/L · Soft15.Maine1 cities sampled
22.9 mg/L · Soft16.North Dakota1 cities sampled
21.3 mg/L · Soft17.Louisiana2 cities sampled
20.9 mg/L · Soft18.Maryland1 cities sampled
20 mg/L · Soft19.Virginia2 cities sampled
14.9 mg/L · Soft20.Missouri3 cities sampled
14.2 mg/L · SoftTOP 20 CITIES
#1
Mesa, AZVery hard
EPA UCMR5 monitoring
525 mg/L
#2
Chandler, AZVery hard
EPA UCMR5 monitoring
305 mg/L
#3
Phoenix, AZVery hard
Phoenix Water Services CCR 2024
288 mg/L
#4
San Antonio, TXVery hard
SAWS 2025 Water Quality Report
272 mg/L
#5
Gilbert, AZVery hard
EPA UCMR5 monitoring
258 mg/L
#6
Los Angeles, CAVery hard
LADWP CCR 2024
235 mg/L
#7
Dallas, TXVery hard
Dallas Water Public water systems CCR 2024
210 mg/L
#8
Parkersburg, WVVery hard
Parkersburg Public water system Board CCR 2024
205 mg/L
#9
Sugar Land, TXVery hard
Sugar Land Public water system CCR 2024
200 mg/L
#10
Fort Worth, TXVery hard
Fort Worth Water Dept CCR 2024
195 mg/L
#11
Houston, TXHard
Houston Water CCR 2024
175 mg/L
#12
Miami, FLHard
MDWASA CCR 2024
165 mg/L
#13
Peoria, AZHard
EPA UCMR5 monitoring
162 mg/L
#14
Scottsdale, AZHard
EPA UCMR5 monitoring
160 mg/L
#15
Chicago, ILHard
Chicago DWM CCR 2024
145 mg/L
#16
Austin, TXHard
Austin Water CCR 2024
140 mg/L
#17
Columbus, OHHard
Columbus Division of Water CCR 2024
130 mg/L
#18
Fresno, CAModerately hard
City of Fresno CCR 2024
120 mg/L
#19
Glendale, AZModerately hard
EPA UCMR5 monitoring
117 mg/L
#20
El Paso, TXModerately hard
EPA UCMR5 monitoring
115.8 mg/L