74.9
County avg score
16
Cities ranked
69%
A or B grade
31%
D or F grade
14
Health violations
8
PFAS detected
Grade Distribution
How San Luis Obispo cities scored
A
9
56%
Excellent
B
2
13%
Good
C
0
0%
Fair
D
1
6%
Poor
F
4
25%
Failing
Comparison
County vs California average
▼ 1.6 pts below state average
City Map
Water quality across San Luis Obispo
Each dot is a city, colored by grade. Click any city to view its full report.
Highlights
Top & bottom cities in San Luis Obispo
County context
1
Superfund site in San Luis Obispo
71
lbs/yr to surface water · top 10 TRI facilities
Industrial pollution
Top industrial polluters in San Luis Obispo
Industrial polluters nearby
Facilities reporting the most surface-water releases in San Luis Obispo, 2023.
Total reported releases to surface water: 71 lbs
| Facility | Top chemical | To surface water (lbs/yr) |
|---|---|---|
PHILLIPS 66 CO-SANTA MARIA REFINERY ARROYO GRANDE, CA93420 | Phenol | 71 |
PROMEGA CORP SAN LUIS OBISPO, CA93401 | — | — |
RANTEC POWER SYSTEMS INC LOS OSOS, CA93402 | — | — |
U.S. ARMY NATIONAL GUARD CAMP SAN LUIS OBISPO RANGES SAN LUIS OBISPO, CA93405 | — | — |
CALPORTLAND CO SAN LUIS OBISPO SAN LUIS OBISPO, CA93401 | — | — |
+ 5 more facilities
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites
Superfund sites in San Luis Obispo
Superfund sites nearby
Federally tracked hazardous-waste sites within San Luis Obispo on the EPA National Priorities List.
- KLAU BUENA VISTA MINE
Source: EPA Superfund National Priorities List
Full Rankings
All 16 cities in San Luis Obispo
| # | City | Grade | Score | Score | Population | Violations | Issues |
|---|---|---|---|---|---|---|---|
| 1 | San Miguel | A+ | 97 | 3K | 1 | ||
| 2 | Cayucos | A+ | 95.7 | 5K | 2 | Health | |
| 3 | Templeton | A | 94.2 | 9K | 6 | Health Unresolved | |
| 4 | Nipomo | A | 92.2 | 14K | 4 | Health | |
| 5 | Oceano | A | 90.7 | 8K | 11 | Health Unresolved | |
| 6 | Avila Beach | A- | 89 | 3K | 3 | Health | |
| 7 | Cambria | A- | 88.5 | 6K | 9 | Health Unresolved | |
| 8 | Pismo Beach | A- | 86.8 | 9K | 6 | Health Unresolved | |
| 9 | Morro Bay | A- | 86.5 | 14K | 21 | Health Unresolved | |
| 10 | Los Osos | B+ | 84.8 | 8K | 5 | PFAS Unresolved | |
| 11 | Atascadero | B | 77.3 | 35K | 14 | Health PFAS Unresolved | |
| 12 | Bradley | D+ | 52.8 | 2K | 79 | Health Unresolved | |
| 13 | Grover Beach | F | 43.8 | 13K | 45 | Health Unresolved | |
| 14 | Arroyo Grande | F | 40.5 | 24K | 158 | Health PFAS Unresolved | |
| 15 | San Luis Obispo | F | 39.4 | 70K | 110 | Health Unresolved | |
| 16 | Paso Robles | F | 39 | 36K | 93 | Health PFAS Unresolved |