68.8
County avg score
8
Cities ranked
63%
A or B grade
25%
D or F grade
7
Health violations
3
PFAS detected
Grade Distribution
How Johnson cities scored
A
1
13%
Excellent
B
4
50%
Good
C
1
13%
Fair
D
0
0%
Poor
F
2
25%
Failing
Comparison
County vs Iowa average
▼ 19.0 pts below state average
City Map
Water quality across Johnson
Each dot is a city, colored by grade. Click any city to view its full report.
Highlights
Top & bottom cities in Johnson
Worst cities
County context
92.5%
of residents on fluoridated water (CDC, 2020)
10
lbs/yr to surface water · top 10 TRI facilities
Industrial pollution
Top industrial polluters in Johnson
Industrial polluters nearby
Facilities reporting the most surface-water releases in Johnson, 2023.
Total reported releases to surface water: 10 lbs
| Facility | Top chemical | To surface water (lbs/yr) |
|---|---|---|
PROCTER & GAMBLE HAIR CARE LLC IOWA CITY, IA52240 | Zinc compounds | 10 |
LOPAREX LLC IOWA CITY, IA52240 | Toluene | 0 |
ROCKWELL COLLINS INC CORALVILLE OPERATIONS CORALVILLE, IA52241 | — | — |
HUBBARD FEEDS INC IOWA CITY, IA52240 | — | — |
INTEGRATED DNA TECHNOLOGIES CORALVILLE, IA52241 | — | — |
+ 1 more facility
Source: EPA Toxic Release Inventory (TRI) 2023
Full Rankings
All 8 cities in Johnson
| # | City | Grade | Score | Score | Population | Violations | Issues |
|---|---|---|---|---|---|---|---|
| 1 | Hills | A- | 86.4 | 863 | 2 | Unresolved | |
| 2 | Tiffin | B+ | 84.7 | 5K | 25 | Health Unresolved | |
| 3 | Lone Tree | B+ | 80.6 | 1K | 17 | Health Unresolved | |
| 4 | Coralville | B | 77.3 | 22K | 104 | Health Unresolved | |
| 5 | North Liberty | B- | 70 | 21K | 120 | Health Unresolved | |
| 6 | Oxford | C+ | 65.2 | 1K | 114 | Health Unresolved | |
| 7 | Solon | F | 44 | 4K | 364 | Health Unresolved | |
| 8 | Iowa City | F | 42 | 97K | 691 | Health Unresolved |