Lake Water Quality Report
10 cities ranked · Average grade: B · California
Avg Score
77.2
Cities Ranked
10
Health Violations
10
PFAS Detected
4
77.2
County avg score
10
Cities ranked
70%
A or B grade
10%
D or F grade
10
Health violations
4
PFAS detected
Grade Distribution
How Lake cities scored
A
2
20%
Excellent
B
5
50%
Good
C
2
20%
Fair
D
1
10%
Poor
F
0
0%
Failing
Comparison
County vs California average
▲ 0.7 pts above state average
City Map
Water quality across Lake
Each dot is a city, colored by grade. Click any city to view its full report.
Highlights
Top & bottom cities in Lake
County context
1
Superfund site in Lake
0
lbs/yr to surface water · top 10 TRI facilities
Industrial pollution
Top industrial polluters in Lake
Industrial polluters nearby
Facilities reporting the most surface-water releases in Lake, 2023.
| Facility | Top chemical | To surface water (lbs/yr) |
|---|---|---|
GRANITE CONSTRUCTION CO - HIGHWAY 175 LAKEPORT, CA95453 | — | — |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites
Superfund sites in Lake
Superfund sites nearby
Federally tracked hazardous-waste sites within Lake on the EPA National Priorities List.
- SULPHUR BANK MERCURY MINE
Source: EPA Superfund National Priorities List
Full Rankings
All 10 cities in Lake
| # | City | Grade | Score | Score | Population | Violations | Issues |
|---|---|---|---|---|---|---|---|
| 1 | Hidden Valley Lake | A+ | 98.2 | 6K | 1 | Health | |
| 2 | Nice | A+ | 95.4 | 3K | 3 | Health | |
| 3 | Lower Lake | B+ | 83.8 | 2K | 61 | Health Unresolved | |
| 4 | Clearlake | B+ | 82 | 14K | 8 | Health Unresolved | |
| 5 | Clearlake Oak | B+ | 81.2 | 2K | 10 | Health Unresolved | |
| 6 | Upper Lake | B | 79 | 1K | 107 | Health Unresolved | |
| 7 | Kelseyville | B- | 72.2 | 7K | 126 | Health Unresolved | |
| 8 | Cobb | C+ | 69.2 | 4K | 24 | Health Unresolved | |
| 9 | Lakeport | C- | 57.5 | 18K | 44 | Health Lead Unresolved | |
| 10 | Middletown | D+ | 53.5 | 3K | 97 | Health Unresolved |