WATER SAFETY SCORE · 0–88
25 worst cities for tap water quality
Ranked by our Water Safety Score— the same 0–88 exposure profile used on each city report. Regulatory PFAS MCL violations weigh heaviest; monitoring detections and lead, DBP, and chromium flags in our profiles add smaller penalties. This is not your ZIP's live SDWIS compliance score.
Only tracked metros with WaterCheckup city guides (25 shown). For PFAS-only leaderboards see peak PFAS systems and PFAS MCL cities.
WaterCheckup Safety Score — an independent index from EPA public data and our formula. Not your utility’s official water quality rating, an EPA compliance grade, or a test of water at your tap. How we score →
POPULAR CITY WATER REPORTS
Gaithersburg, MD
Grade B · 74/88
WSSC Water · PFAS & testing context
Gaithersburg water quality · water testing Gaithersburg MD · WSSC tap water
Free full report →
San Antonio, TX
Grade D+ · 59/88
272 mg/L hardness · PFAS in UCMR5
San Antonio water quality · PFAS in San Antonio water · water contamination
Free full report →
Raleigh, NC
Grade C · 66/88
GenX/PFAS zone · THM violations
Raleigh water quality · PFAS Raleigh NC · Wake County tap water
Free full report →
Philadelphia, PA
Grade F · 42/88
Lead lines · Delaware River PFAS
Philadelphia water quality · Philly PFAS · Philadelphia lead pipes
Free full report →
San Diego, CA
Grade B+ · 78/88
Imported water · PFAS & hardness
San Diego water quality · San Diego PFAS · San Diego hard water
Free full report →
Baltimore, MD
Grade B+ · 77/88
Lead at tap · aging mains
Baltimore water quality · Baltimore lead water · city water testing Baltimore
Free full report →
Fairfax County, VA
Grade D · 54/88
PFAS MCL flags · NoVA systems
Fairfax County water quality · Northern Virginia PFAS · Fairfax tap water
Free full report →
Nashville, TN
Grade D · 56/88
Cumberland River · PFAS monitoring
Nashville water quality · Nashville tap water safe · Metro Nashville PFAS
Free full report →
Chicago, IL
Grade D- · 51/88
400k+ lead lines · PFAS monitoring
Chicago tap water quality · Chicago lead pipes · Chicago water PFAS
Free full report →
Houston, TX
Grade C+ · 67/88
22.4 ppt PFAS · Ship Channel legacy
Houston tap water safe · Houston PFAS · Houston water quality 2026
Free full report →
Phoenix, AZ
Grade C- · 63/88
7.4 ppt PFAS · very hard water
Phoenix tap water quality · Phoenix PFAS · Phoenix water hardness
Free full report →
New York City, NY
Grade B+ · 78/88
PFOS 106 ppt · building lead risk
NYC tap water safe · NYC water PFAS · NYC lead pipes
Free full report →
#1
Pensacola, FLGrade F
PFAS Above EPA Limit · 55K residents
34/88
#2
Fort Worth, TXGrade F
PFAS Above EPA Limit · 936K residents
39/88
#3
Sacramento, CAGrade F
PFAS Above EPA Limit · 524K residents
41/88
#4
Philadelphia, PAGrade F
PFAS Above EPA Limit · 1.6M residents
42/88
#5
Rochester, NYGrade F
PFAS Above EPA Limit · 210K residents
42/88
#6
Boise, IDGrade F
PFAS Above EPA Limit · 240K residents
43/88
#7
Fort Collins, COGrade F
PFAS Above EPA Limit · 165K residents
43/88
#8
Fresno, CAGrade F
PFAS Above EPA Limit · 546K residents
43/88
#9
Jackson, MSGrade F
PFAS Above EPA Limit · 150K residents
43/88
#10
Miami, FLGrade F
PFAS Above EPA Limit · 2.8M residents
43/88
#11
Gilbert, AZGrade F
PFAS Above EPA Limit · 260K residents
44/88
#12
Madison, WIGrade F
PFAS Above EPA Limit · 270K residents
44/88
#13
Milwaukee, WIGrade F
PFAS Above EPA Limit · 590K residents
44/88
#14
Newark, NJGrade F
PFAS Above EPA Limit · 310K residents
45/88
#15
Anaheim, CAGrade F
PFAS Above EPA Limit · 350K residents
46/88
#16
Savannah, GAGrade F
PFAS Above EPA Limit · 145K residents
46/88
#17
Birmingham, ALGrade F
PFAS Above EPA Limit · 210K residents
48/88
#18
Detroit, MIGrade F
PFAS Above EPA Limit · 630K residents
48/88
#19
Grand Rapids, MIGrade F
PFAS Above EPA Limit · 195K residents
48/88
#20
Hartford, CTGrade F
PFAS Above EPA Limit · 125K residents
48/88
#21
Sugar Land, TXGrade F
PFAS Above EPA Limit · 91K residents
48/88
#22
Dallas, TXGrade F
PFAS Above EPA Limit · 1.3M residents
49/88
#23
Reno, NVGrade F
PFAS Above EPA Limit · 260K residents
49/88
#24
Fayetteville, NCGrade D-
PFAS Above EPA Limit · 210K residents
50/88
#25
Greensboro, NCGrade D-
PFAS Above EPA Limit · 290K residents
50/88