94022
Los Altos Hills, CA
Santa Clara County · San Jose-Sunnyvale-Santa Clara, CA metro area
CWSC LOS ALTOS SUBURBAN

Is Los Altos Hills tap water safe to drink?

Some concern
Last tested: September 2025
Source: Official EPA UCMR5 federal monitoring data. Last tested September 2025.
Townships:
  • West Santa Clara CCD, CA
  • San Jose CCD, CA
Neighborhoods:
  • Alta Mesa
  • Gemello
  • Green Acres
  • Saint Francis Acres
  • Monroe Park
  • Palo Alto Orchards

The short answer for Los Altos Hills

Los Altos Hills tap water has 5 detected contaminants, currently below EPA limits (tested January 2024). 6:2 FTS measured closest to the threshold. See the full compound-by-compound report.

The health risk for Los Altos Hills

PFAS traces were detected in local water tests, though levels are currently below EPA limits. Since no amount of PFAS is considered completely safe by health researchers, a certified filter adds a meaningful layer of protection, especially for children.
  • PFAS or other chemicals detected; no confirmed exceedances in multiple samples.
6:2 FTS concentration (µg/L) January 2024
0 µg/L 0.005 µg/L 0.01 µg/L
0.005 µg/L
Detected
µg/L
0.005 µg/L
EPA limit
guideline
100% of limit
Comparison
vs. guideline
EPA limit: 0.005 µg/L | Your water: 0.005 µg/L
Add a Layer of Protection for Los Altos Hills Tap Water

6:2 FTS (a PFAS 'forever chemical') was detected below EPA limits. A certified filter can still add an extra layer of protection.

Water filter recommendation for Los Altos Hills tap water: Epic Pure XP Water Filter Pitcher
Pitcher filter
Epic Pure XP Water Filter Pitcher
NSF-certified dual-layer filtration reduces 70+ contaminants including PFAS, lead, chlorine, microplastics, and bacteria.
NSF/ANSI 42, 53, 401 & P473Removes 99.99% PFASMade in USABPA-free
Most elevated compounds
Compound Measurement EPA Limit Comparison
6:2 FTS
Tested: January 2024 · Well 121-2
0.005 µg/L 0.005 µg/L 100% of limit
4:2 FTS
Tested: January 2024 · Well 06-02-EFF
0.003 µg/L 0.003 µg/L 100% of limit
8:2 FTS
Tested: January 2024 · Well 21-01
0.005 µg/L 0.005 µg/L 100% of limit
PFHxS
Tested: January 2024 · Well 21-01
0.004 µg/L 0.004 µg/L 88% of limit
PFHxS
Tested: April 2024 · Well 39-1
0.003 µg/L 0.004 µg/L 77% of limit
View all tested compounds

Connection to SDPUC Hillview Miranda · Tested: September 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

SCVWD Intertie · Tested: April 2024

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

SFPUC Intertie · Tested: June 2024

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

SFPUC Woodside Connection · Tested: October 2024

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

SJWC Intertie · Tested: April 2024

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

Well 06-02-EFF · Tested: January 2024

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

Well 104-2 · Tested: January 2024

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

Well 116-1(GWRMP) · Tested: January 2024

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

Well 119-3 · Tested: December 2023

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

Well 121-2 · Tested: January 2024

Compound Measurement EPA Limit Comparison
6:2 FTS 0.005 µg/L 0.005 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

Well 123-1 · Tested: January 2024

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

Well 15-1 · Tested: December 2023

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

Well 17-1 · Tested: December 2023

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

Well 18-2 (GWRMP) · Tested: December 2023

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

Well 21-01 · Tested: January 2024

Compound Measurement EPA Limit Comparison
8:2 FTS 0.005 µg/L 0.005 µg/L 100% of limit
PFHxS 0.004 µg/L 0.004 µg/L 88% of limit
lithium <9.000 µg/L 10 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

Well 25-01 (GWRMP) · Tested: Multiple dates

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

Well 27-1 (GWRMP) · Tested: December 2023

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

Well 34-1 · Tested: December 2023

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

Well 39-1 · Tested: April 2024

Compound Measurement EPA Limit Comparison
PFHxS 0.003 µg/L 0.004 µg/L 77% of limit
lithium <9.000 µg/L 10 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 94022

Service area boundaries are approximate and based on state filings or modeled estimates. Contact your utility to confirm exact service at a specific address.

Modeled boundaries are shown with a dashed outline.

Frequently Asked Questions about ZIP 94022 Tap Water

What's in ZIP 94022 tap water?

ZIP 94022 has 5 detected contaminants below EPA limits in this dataset. 6:2 FTS measured closest to its guideline.

Will boiling ZIP 94022 tap water remove 6:2 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 94022, a certified filter is more reliable.

Do basic pitcher filters remove 6:2 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 94022?

Public records identify CWSC LOS ALTOS SUBURBAN as a primary water system associated with ZIP 94022. Service boundaries can vary by address, so confirm exact service with the utility.

When was ZIP 94022 tap water last tested?

The most recent test date used in this report is September 2025. EnviroClarity last refreshed this page on 2026-05-04.

Where can I find the official water quality report for ZIP 94022?

Every U.S. public water system is required to publish an annual Consumer Confidence Report (CCR). Contact CWSC LOS ALTOS SUBURBAN or visit their website for the latest official report covering ZIP 94022. The EPA also maintains a national CCR locator.

Primary source EPA UCMR5 (2023-2025)
Guideline source EPA drinking water standard (PFTrDA: 0,007 µg/L)
Last tested September 2025
Last page update 2026-05-04

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    Data reflects publicly reported utility records from EPA datasets and local utility disclosures. This information is educational and not medical advice.

    Filter Los Altos Hills tap water → see certified options