Public water system
Atascadero Mutual Water Co
PWSID CA4010002 - San Luis Obispo County, California
350 PPM
20.5 GPG
Very Hard0Soft60120180300+
Very Hard (350 PPM)Verified - State Lab Tested
System Details
- Water source
- groundwater
- Population served
- 30,618
- Service connections
- 10,961
- Status
- Active
Hardness Evidence
- Reported hardness
- 350 PPM
- Grains per gallon
- 20.5 GPG
- Data source
- California treated-water report
- Source year
- 2024
- Raw/source estimate
- 576 PPM
Linked City Reports
Served ZIP Codes
| ZIP | Location | ZIP average |
|---|---|---|
| 93401 | San Luis Obispo, CA | Very Hard (371 PPM) |
| 93402 | Los Osos, CA | Very Hard (369 PPM) |
| 93405 | San Luis Obispo, CA | Very Hard (372 PPM) |
| 93420 | Halcyon, CA | Very Hard (370 PPM) |
| 93422 | Atascadero, CA | Very Hard (372 PPM) |
| 93424 | Avila Beach, CA | Very Hard (372 PPM) |
| 93428 | Cambria, CA | Very Hard (383 PPM) |
| 93430 | Cayucos, CA | Very Hard (370 PPM) |
| 93432 | Creston, CA | Very Hard (372 PPM) |
| 93433 | Grover Beach, CA | Very Hard (372 PPM) |
| 93442 | Morro Bay, CA | Very Hard (372 PPM) |
| 93444 | Nipomo, CA | Very Hard (372 PPM) |
| 93445 | Oceano, CA | Very Hard (385 PPM) |
| 93446 | Adelaide, CA | Very Hard (368 PPM) |
| 93449 | Shell Beach, CA | Very Hard (373 PPM) |
| 93451 | Parkfield, CA | Very Hard (373 PPM) |
| 93452 | San Simeon, CA | Very Hard (373 PPM) |
| 93453 | California Valle, CA | Very Hard (372 PPM) |
| 93461 | Shandon, CA | Very Hard (372 PPM) |
| 93465 | Templeton, CA | Very Hard (380 PPM) |
How to Use This System Page
A public water system can serve multiple ZIP codes and cities. Use this page to inspect the source behind the hardness reading, then open the linked ZIP or city page for the local rollup.
If you are sizing treatment equipment, confirm your actual tap hardness with a home test or lab test before buying.