Public water system
Contra Costa Water District
PWSID CA0710003 - Contra Costa County, California
76 PPM
4.4 GPG
Slightly Hard0Soft60120180300+
Slightly Hard (76 PPM)Verified - State Lab Tested
System Details
- Water source
- surface water
- Population served
- 198,000
- Service connections
- 60,730
- Status
- Active
Hardness Evidence
- Reported hardness
- 76 PPM
- Grains per gallon
- 4.4 GPG
- Data source
- California treated-water report
- Source year
- 2024
- Raw/source estimate
- 422 PPM
Linked City Reports
Black Hawk, CAAlamo, CAAntioch, CABethel Island, CABrentwood, CAByron, CAClayton, CAConcord, CAPleasant Hill, CACrockett, CADanville, CAEl Cerrito, CAHercules, CALafayette, CAPacheco, CAMoraga, CAOakley, CAOrinda, CAPinole, CAShore Acres, CAPort Costa, CARodeo, CASan Ramon, CAWalnut Creek, CARichmond, CAEl Sobrante, CASan Pablo, CA
Served ZIP Codes
| ZIP | Location | ZIP average |
|---|---|---|
| 94506 | Black Hawk, CA | Slightly Hard (105 PPM) |
| 94507 | Alamo, CA | Slightly Hard (105 PPM) |
| 94509 | Antioch, CA | Slightly Hard (105 PPM) |
| 94511 | Bethel Island, CA | Slightly Hard (105 PPM) |
| 94513 | Brentwood, CA | Slightly Hard (105 PPM) |
| 94514 | Byron, CA | Slightly Hard (105 PPM) |
| 94517 | Clayton, CA | Slightly Hard (105 PPM) |
| 94518 | Concord, CA | Slightly Hard (105 PPM) |
| 94519 | Concord, CA | Slightly Hard (105 PPM) |
| 94520 | Concord, CA | Slightly Hard (105 PPM) |
| 94521 | Concord, CA | Slightly Hard (105 PPM) |
| 94523 | Pleasant Hill, CA | Slightly Hard (105 PPM) |
| 94525 | Crockett, CA | Slightly Hard (105 PPM) |
| 94526 | Danville, CA | Slightly Hard (105 PPM) |
| 94530 | El Cerrito, CA | Slightly Hard (105 PPM) |
| 94547 | Hercules, CA | Slightly Hard (105 PPM) |
| 94549 | Lafayette, CA | Slightly Hard (105 PPM) |
| 94553 | Pacheco, CA | Slightly Hard (105 PPM) |
| 94556 | Moraga, CA | Slightly Hard (105 PPM) |
| 94561 | Oakley, CA | Slightly Hard (105 PPM) |
| 94563 | Orinda, CA | Slightly Hard (105 PPM) |
| 94564 | Pinole, CA | Slightly Hard (105 PPM) |
| 94565 | Shore Acres, CA | Slightly Hard (105 PPM) |
| 94569 | Port Costa, CA | Slightly Hard (105 PPM) |
| 94572 | Rodeo, CA | Slightly Hard (105 PPM) |
| 94583 | San Ramon, CA | Slightly Hard (105 PPM) |
| 94595 | Walnut Creek, CA | Slightly Hard (105 PPM) |
| 94596 | Walnut Creek, CA | Slightly Hard (105 PPM) |
| 94598 | Walnut Creek, CA | Slightly Hard (105 PPM) |
| 94801 | Richmond, CA | Slightly Hard (105 PPM) |
| 94803 | El Sobrante, CA | Slightly Hard (105 PPM) |
| 94804 | Richmond, CA | Slightly Hard (105 PPM) |
| 94805 | Richmond, CA | Slightly Hard (105 PPM) |
| 94806 | San Pablo, CA | Slightly Hard (105 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.