San Luis Obispo County, CA
The federal environmental record for San Luis Obispo County (population 281,639): what is on file, where it is, and what remains open. Sources and retrieval dates are on the methodology page.
1
Superfund NPL sites
3
federal cleanup sites
8
PFAS-detecting water systems
12
TRI facilities
3
open tank releases
Superfund NPL sites
| Site | City | Status | Listed |
|---|---|---|---|
| Klau/Buena Vista Mine | Paso Robles | on the NPL | 04/19/2006 |
Drinking water: PFAS testing
Public water systems serving San Luis Obispo with at least one PFAS detection under UCMR5. The federal limit for PFOA and PFOS is 4 ng/L; EPA proposed in May 2026 to rescind the limits for the other compounds, which are shown for information.
| System | Highest results | Reading |
|---|---|---|
| ARROYO GRANDE, WATER DEPARTMENT CA4010001 | PFBS: 11 ng/L PFOS: 6.8 ng/L PFOA: 5.8 ng/L | above final limit |
| ATASCADERO MUTUAL WATER CO CA4010002 | PFOS: 22.3 ng/L PFBA: 10 ng/L PFBS: 9.4 ng/L | above final limit |
| PASO ROBLES WATER DEPARTMENT CA4010007 | PFPeA: 22 ng/L PFHxA: 20 ng/L PFBS: 8.1 ng/L | above final limit |
| LOS OSOS COMMUNITY SERVICES DISTRICT CA4010016 | PFBS: 18 ng/L PFPeA: 16.8 ng/L PFHxA: 16.6 ng/L | above final limit |
| ATASCADERO STATE HOSPITAL CA4010832 | PFHxS: 34 ng/L PFOS: 33 ng/L PFPeS: 6.1 ng/L | above final limit |
| GOLDEN STATE WATER COMPANY - LOS OSOS CA4010017 | PFHxS: 8.8 ng/L PFHxA: 4.3 ng/L PFPeA: 3.4 ng/L | detected |
| GOLDEN STATE WATER COMPANY - NIPOMO CA4010018 | PFPeA: 3.2 ng/L | detected |
| TEMPLETON CSD CA4010019 | PFBS: 6.8 ng/L PFHxS: 3.2 ng/L | detected |
On a system with detections? Testing and treatment options
Facilities reporting toxic releases (2024)
12 facilities in San Luis Obispo filed TRI reports for 2024, totalling 26k lb released.
| Facility | City | Top chemicals | Total released |
|---|---|---|---|
| JOSLYN SUNBANK CO LLC | PASO ROBLES | Nickel compounds, Nitric acid | 12k lb |
| U.S. ARMY NATIONAL GUARD CAMP SAN LUIS OBISPO RANGES | SAN LUIS OBISPO | Lead | 9k lb |
| U.S. ARMY NATIONAL GUARD CAMP ROBERTS RANGES | CAMP ROBERTS | Lead | 3k lb |
| PROMEGA CORP | SAN LUIS OBISPO | Dichloromethane | 1k lb |
| RANTEC POWER SYSTEMS INC | LOS OSOS | Lead | 248 lb |
| ENTEGRIS - SAN LUIS OBISPO | SAN LUIS OBISPO | - | 0 lb |
| CALPORTLAND CO PASO ROBLES ASPHALT | TEMPLETON | - | 0 lb |
| ZURN WATER LLC | PASO ROBLES | - | 0 lb |
| CALPORTLAND CO PASO ROBLES PLANT | TEMPLETON | - | 0 lb |
| FIRESTONE WALKER LLC | PASO ROBLES | - | 0 lb |
| COAST SOUTHWEST SURFACTANTS LLC | PASO ROBLES | - | 0 lb |
| CALPORTLAND CO SAN LUIS OBISPO | SAN LUIS OBISPO | - | 0 lb |
Underground fuel tanks
EPA's UST Finder records 128 tank facilities in San Luis Obispo: 363 tanks in service and 0 closed. 275 fuel releases are on record, of which 3 remain open. Open releases are cleanups that have not reached "no further action".
Radon
EPA maps San Luis Obispo as Zone 2, moderate predicted indoor radon (2 to 4 pCi/L average). Radon and air quality are covered in depth on lung.com.
The record for one specific address
County figures blur what matters: distance. The Address Environmental Report runs these same federal datasets against one address and reports every site, tank, polluter and water result around it, with distances, in about a minute.
Get the report - $39All federal cleanup sites on file
The wider Superfund enterprise inventory (SEMS) for San Luis Obispo, including sites assessed but never listed. Presence here records that EPA had reason to look, not a finding of danger.
- CAMP ROBERTS TRAINING SITECAMP ROBERTS
- RINCONADA MINESANTA MARGARITA
- USDLA DEFENSE FUEL SUPPLY PT MORRO BAYMORRO BAY