93402
Los Osos, CA
San Luis Obispo County · San Luis Obispo-Paso Robles, CA metro area
LOS OSOS COMMUNITY SERVICES DISTRICT

Is Los Osos tap water safe to drink?

Higher concern
Last tested: July 2024
Source: Official EPA UCMR5 federal monitoring data. Last tested July 2024.
Township:
  • North Coast CCD, CA
Neighborhood:
  • Los Osos

The short answer for Los Osos

Los Osos tap water has 11 contaminants above EPA guidelines, including PFBS at 6.0× the limit (tested July 2024). See the full compound-by-compound breakdown and filter recommendations.

The health risk for Los Osos

PFAS ('forever chemicals') have been detected above EPA limits in this water system's most recent tests. These synthetic chemicals do not break down in the body and are linked to a range of health effects. A certified filter is strongly recommended.
  • lithium, PFBS, PFHpA, PFHxS, PFOA, PFOS, PFPeA above limit.
PFBS concentration (µg/L) July 2024
0 µg/L 0.003 µg/L 0.02 µg/L
0.018 µg/L
Detected
µg/L
0.003 µg/L
EPA limit
guideline
500% above limit
Comparison
vs. guideline
EPA limit: 0.003 µg/L | Your water: 0.018 µg/L
Certified Filters for Los Osos Tap Water

PFBS (a PFAS 'forever chemical') was detected above EPA limits. These filters are independently certified to reduce common drinking-water contaminants.

Water filter recommendation for Los Osos 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
PFBS
Tested: July 2024 · South Bay Upper Aquifer Treated
0.018 µg/L 0.003 µg/L 500% above limit
PFPeA
Tested: July 2024 · South Bay Upper Aquifer Treated
0.017 µg/L 0.003 µg/L 460% above limit
PFOA
Tested: July 2024 · South Bay Upper Aquifer Treated
0.015 µg/L 0.004 µg/L 268% above limit
PFOS
Tested: July 2024 · South Bay Upper Aquifer Treated
0.012 µg/L 0.004 µg/L 192% above limit
PFHxS
Tested: July 2024 · South Bay Upper Aquifer Treated
0.008 µg/L 0.004 µg/L 110% above limit
View all tested compounds

South Bay Upper Aquifer Treated · Tested: July 2024

Compound Measurement EPA Limit Comparison
PFBS 0.018 µg/L 0.003 µg/L 500% above limit
PFPeA 0.017 µg/L 0.003 µg/L 460% above limit
PFOA 0.015 µg/L 0.004 µg/L 268% above limit
PFOS 0.012 µg/L 0.004 µg/L 192% above limit
PFHxS 0.008 µg/L 0.004 µg/L 110% above limit
PFHpA 0.005 µg/L 0.003 µg/L 80% above limit
PFHxA 0.017 µg/L 3 µg/L 0.6% of limit
PFBA 0.006 µg/L 6 µg/L 0.1% 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
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
PFDA <0.003 µg/L 0.003 µg/L Below limit
PFDoA <0.003 µg/L 0.003 µg/L Below limit
PFHpS <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

10th Street Well · Tested: July 2024

Compound Measurement EPA Limit Comparison
lithium 10.500 µg/L 10 µg/L 5% above 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

8th Street Well Treated · Tested: July 2024

Compound Measurement EPA Limit Comparison
lithium 13.000 µg/L 10 µg/L 30% above 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

Los Olivos Resv Nitrate Blend Effluent · Tested: Multiple dates

Compound Measurement EPA Limit Comparison
PFHxS 0.008 µg/L 0.004 µg/L 102% above limit
PFHxA 0.004 µg/L 3 µg/L 0.1% 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
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

Pallisades Well · Tested: July 2024

Compound Measurement EPA Limit Comparison
lithium 16.100 µg/L 10 µg/L 61% above 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

Rosina IX TP Effluent - Nitrate Treated · Tested: Multiple dates

Compound Measurement EPA Limit Comparison
PFPeA 0.003 µg/L 0.003 µg/L 10% above limit
PFHxA 0.003 µg/L 3 µg/L 0.1% 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
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
PFTrDA <0.007 µg/L 0.007 µg/L Below limit
PFUnA <0.002 µg/L 0.002 µg/L Below limit

3rd Street Well · Tested: July 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

8th Street Upper Well Treated · Tested: July 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

Cabrillo Well - Fe/Mn Treated · 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

South Bay Lower Aquifer Treated · Tested: July 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

South Bay Well 01 · Tested: August 2023

Compound Measurement EPA Limit Comparison
lithium 9.600 µg/L 10 µg/L 96% of 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 93402

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 93402 Tap Water

What contaminants are above EPA limits in ZIP 93402?

ZIP 93402 has 11 contaminants above EPA health guidelines in the latest available data, including PFBS at 6.0x the EPA guideline. The full table on this page lists every tested compound and its measured level.

Will boiling ZIP 93402 tap water remove PFBS?

No. Boiling does not remove PFAS, and the compounds can actually become more concentrated as water evaporates. To reduce PFAS at home, use a filter independently certified to NSF/ANSI P473 (activated-carbon pitcher or under-sink) or NSF/ANSI 58 (reverse osmosis).

Do basic pitcher filters remove PFBS?

Most basic pitcher filters are only certified to NSF/ANSI 42 or 53, which do not cover PFAS. Look for a filter independently certified to NSF/ANSI P473 (activated-carbon pitcher or under-sink) or NSF/ANSI 58 (reverse osmosis) on the spec sheet.

Who provides tap water in ZIP 93402?

Public records identify LOS OSOS COMMUNITY SERVICES DISTRICT as a primary water system associated with ZIP 93402. Service boundaries can vary by address, so confirm exact service with the utility.

When was ZIP 93402 tap water last tested?

The most recent test date used in this report is July 2024. EnviroClarity last refreshed this page on 2026-05-04.

Where can I find the official water quality report for ZIP 93402?

Every U.S. public water system is required to publish an annual Consumer Confidence Report (CCR). Contact LOS OSOS COMMUNITY SERVICES DISTRICT or visit their website for the latest official report covering ZIP 93402. The EPA also maintains a national CCR locator.

Primary source EPA UCMR5 (2023-2025)
Guideline source EPA drinking water standard (lithium: 10 µg/L)
Last tested July 2024
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.

    Protect your water in Los Osos → see certified filters