Is San Carlos tap water safe to drink?
- San Mateo CCD, CA
- Silver Penny Mobile Home Park
- Redwood Shores
- Farm Hills
- Laurel
- Hillsdale
- Sequoia Mobile Home Park
The short answer for San Carlos
San Carlos tap water has 1 detected contaminant, currently below EPA limits (tested January 2025). 4:2 FTS measured closest to the threshold. See the full compound-by-compound report.
The health risk for San Carlos
- PFAS or other chemicals detected; no confirmed exceedances in multiple samples.
4:2 FTS (a PFAS 'forever chemical') was detected below EPA limits. A certified filter can still add an extra layer of protection.
Here's what actually removes PFAS from your water
The right filter eliminates PFAS at the tap. But not all filters do - and the type you choose matters for your home.
Common pitchers like Brita do not remove PFAS. You need a filter independently certified to NSF P473 (for pitcher filters) or NSF/ANSI 58 (for reverse osmosis systems). All three options below carry the relevant certification.
| Compound | Measurement | EPA Limit | Comparison |
|---|---|---|---|
| 4:2 FTS Tested: January 2025 · SFWD Intertie |
0.003 µg/L | 0.003 µg/L | 100% of limit |
View all tested compounds
SFWD Intertie · Tested: January 2025
| Compound | Measurement | EPA Limit | Comparison |
|---|---|---|---|
| 4:2 FTS | 0.003 µg/L | 0.003 µg/L | 100% of limit |
| lithium | <9.000 µg/L | 10 µg/L | Below limit |
| PFHxS | <0.003 µg/L | 0.004 µg/L | Below limit |
| HFPO-DA | <0.005 µg/L | 0.01 µg/L | Below limit |
| PFNA | <0.004 µg/L | 0.01 µg/L | Below limit |
| PFHxA | <0.003 µg/L | 3 µg/L | Below limit |
| PFBA | <0.005 µg/L | 6 µg/L | Below limit |
| 11Cl-PF3OUdS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 4:2 FTS | <0.003 µg/L | 0.003 µg/L | Below limit |
| 6:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 8:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 9Cl-PF3ONS | <0.002 µg/L | 0.002 µg/L | Below limit |
| ADONA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFBS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDoA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFOA | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFOS | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFPeA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFTrDA | <0.007 µg/L | 0.007 µg/L | Below limit |
| PFUnA | <0.002 µg/L | 0.002 µg/L | Below limit |
SFWD Intertie · Tested: June 2025
| Compound | Measurement | EPA Limit | Comparison |
|---|---|---|---|
| lithium | <9.000 µg/L | 10 µg/L | Below limit |
| PFHxS | <0.003 µg/L | 0.004 µg/L | Below limit |
| HFPO-DA | <0.005 µg/L | 0.01 µg/L | Below limit |
| PFNA | <0.004 µg/L | 0.01 µg/L | Below limit |
| PFHxA | <0.003 µg/L | 3 µg/L | Below limit |
| PFBA | <0.005 µg/L | 6 µg/L | Below limit |
| 11Cl-PF3OUdS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 4:2 FTS | <0.003 µg/L | 0.003 µg/L | Below limit |
| 6:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 8:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 9Cl-PF3ONS | <0.002 µg/L | 0.002 µg/L | Below limit |
| ADONA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFBS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDoA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFOA | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFOS | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFPeA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFTrDA | <0.007 µg/L | 0.007 µg/L | Below limit |
| PFUnA | <0.002 µg/L | 0.002 µg/L | Below limit |
Water utilities serving ZIP 94070
Service area boundaries are approximate and based on state filings or modeled estimates. Contact your utility to confirm exact service at a specific address.
- CALIFORNIA WATER SERVICE - SAN CARLOSSome concern
Frequently Asked Questions about ZIP 94070 Tap Water
What's in ZIP 94070 tap water?
ZIP 94070 has 1 detected contaminant below EPA limits in this dataset. 4:2 FTS measured closest to its guideline.
Will boiling ZIP 94070 tap water remove 4:2 FTS?
Boiling tap water can kill many pathogens, but it does not remove most chemical contaminants tracked in EPA monitoring. Several dissolved contaminants can even concentrate as water evaporates. For the chemical contaminants reported in ZIP 94070, a certified filter is more reliable.
Do basic pitcher filters remove 4:2 FTS?
Basic pitcher filters are typically rated for chlorine, taste, and odor (NSF/ANSI 42), not for the broader list of contaminants tracked in EPA monitoring. Match the certification (NSF/ANSI 42, 53, 58, or P473) to the specific compounds listed in this report before assuming a filter helps.
Who provides tap water in ZIP 94070?
Public records identify CALIFORNIA WATER SERVICE - SAN CARLOS as a primary water system associated with ZIP 94070. Service boundaries can vary by address, so confirm exact service with the utility.
When was ZIP 94070 tap water last tested?
The most recent test date used in this report is June 2025. EnviroClarity last refreshed this page on 2026-05-04.
Where can I find the official water quality report for ZIP 94070?
Every U.S. public water system is required to publish an annual Consumer Confidence Report (CCR). Contact CALIFORNIA WATER SERVICE - SAN CARLOS or visit their website for the latest official report covering ZIP 94070. The EPA also maintains a national CCR locator.
Check another ZIP code
Nearby ZIP reports
- 94002 - Belmont tap water report
- 94065 - Redwood Shores, Redwood City tap water report
- 94061 - Farm Hills, Redwood City tap water report
- 94063 - Lindenwood, Redwood City tap water report
- 94403 - Hillsdale, San Mateo tap water report
- 94404 - Foster City tap water report
- 94027 - Atherton tap water report
- 94402 - San Mateo Park, San Mateo tap water report
Data reflects publicly reported utility records from EPA datasets and local utility disclosures. This information is educational and not medical advice.