Sammamish, WA · PFAS · forever chemicals
Is There PFAS in Sammamish Tap Water?
Sammamish, WA: PFOS 11.1 ng/L, 3× EPA's 4 ng/L limit; PFHxS also above. Every PFAS result and filter certifications per compound.
The measurements · EPA UCMR 5
6 of 29 PFAS detected
Each result is read against its own reference. Only PFHxS and PFOS have federal limits. PFPeA and PFPeS have no federal or state limit and are shown for transparency, not graded.
- PFOSFederal MCLPerfluorooctanesulfonic acid11.1ng/LAbove its limit · sampled 2023-05-15 to 2024-02-12Evidence
- PFHxSFederal MCLPerfluorohexanesulfonic acid16.5ng/LAbove its limit · limit under EPA review · sampled 2023-05-15 to 2024-02-12Evidence
- PFBSEPA health advisoryPerfluorobutanesulfonic acid8.8ng/LDetected, below its EPA health advisory · sampled 2023-05-15 to 2024-02-12Evidence
- PFHxAState MCL · MichiganPerfluorohexanoic acid4.3ng/LDetected, below its state limit · sampled 2023-05-15 to 2024-02-12Evidence
- PFPeSNo limitPerfluoropentanesulfonic acid4.1ng/L
No federal or state limit: shown for transparency, not graded.
Detected, no limit · sampled 2023-05-15 to 2024-02-12Evidence - PFPeANo limitPerfluoropentanoic acid3.9ng/L
No federal or state limit: shown for transparency, not graded.
Detected, no limit · sampled 2023-05-15 to 2024-02-12Evidence
All 29 compounds in this record
- PFOAMCLNot detected
- PFOSMCL11.1 ng/L
- PFHxSMCL16.5 ng/L
- PFNAMCLNot detected
- HFPO-DA (GenX)MCLNot detected
- PFBS8.8 ng/L
- PFHxA4.3 ng/L
- PFPeA3.9 ng/L
- PFPeS4.1 ng/L
- 11Cl-PF3OUdSNot detected
- 4:2 FTSNot detected
- 6:2 FTSNot detected
- 8:2 FTSNot detected
- 9Cl-PF3ONSNot detected
- ADONANot detected
- NEtFOSAANot detected
- NFDHANot detected
- NMeFOSAANot detected
- PFBANot detected
- PFDANot detected
- PFDoANot detected
- PFEESANot detected
- PFHpANot detected
- PFHpSNot detected
- PFMBANot detected
- PFMPANot detected
- PFTANot detected
- PFTrDANot detected
- PFUnANot detected
MCL marks the 5 PFAS given a federal limit in EPA's 2024 rule. EPA has proposed rescinding three of those limits; they apply until a final rule.
Results as a table29 results with limit, status, sample date and source
| Contaminant | Result | Limit | Status | Sampled | Source |
|---|---|---|---|---|---|
| Perfluorooctanesulfonic acid (PFOS) | 11.1 ng/L | 4.0 ng/L federal MCL (2024) | Above a historical reference; current applicability unverified | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluorohexanesulfonic acid (PFHxS) | 16.5 ng/L | 10 ng/L federal MCL (2024) | Above a historical reference; current applicability unverified | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluorobutanesulfonic acid (PFBS) | 8.8 ng/L | 2,000 ng/L EPA health advisory (screening, not a legal limit)Screening level, not a legal limit | Within the referenced health-based guidance value | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluorohexanoic acid (PFHxA) | 4.3 ng/L | 400,000 ng/L Michigan EGLE state MCL (strictest US state) | Within a historical reference; current applicability unverified | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluoropentanesulfonic acid (PFPeS) | 4.1 ng/L | No federal or state limit; shown for transparency | Detected, no limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluoropentanoic acid (PFPeA) | 3.9 ng/L | No federal or state limit; shown for transparency | Detected, no limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals) | < 5 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | < 6 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | < 20 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluorobutanoic acid (PFBA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluorodecanoic acid (PFDA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluorododecanoic acid (PFDoA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluoroheptanesulfonic acid (PFHpS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluoroheptanoic acid (PFHpA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluorononanoic acid (PFNA) | < 4 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluorooctanoic acid (PFOA) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluorotetradecanoic acid (PFTA) | < 8 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluorotridecanoic acid (PFTrDA) | < 7 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
| Perfluoroundecanoic acid (PFUnA) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-15 to 2024-02-12 | UCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900) |
How this compares
PFOS across 764 cities with a detected value
Sammamish 11.14 ng/L federal MCL (2024)
3,396 more were below the lab's 4 ng/L reporting limit and aren't plotted, and 34 have no result on record. 66 cities above 25 ng/L are grouped in the last bar. A position here is not a verdict on the water.
Where Sammamish sits11.1 ng/L PFOSHigher than 70% of 764 cities with a detected value.
In Washington
21of 123 city reports
have a regulated PFAS above the federal limit.
PFAS across Washington →What this record covers
- SAMMAMISH PLATEAU WATER & SEWER's water system as a whole, as reported to EPA UCMR 5.
- 29 PFAS compounds, each with its own result.
- Samples taken 2023-05-15 to 2024-02-12.
What is unknown
- The water at your tap. Building plumbing isn't in this record.
- PFAS not listed in the 29 above were not reported in these records.
- Levels since the last sample have not been published.
Treatment capabilities that apply
Test first, then match a certified method.
A tap test can confirm levels at your home before you choose treatment.
Identified concerns
- PFHxS · exceeds the limit
- PFOS · exceeds the limit
- PFBS · detected below the limit
- PFHxA · detected below the limit
- PFPeA · detected, no federal or state limit
- PFPeS · detected, no federal or state limit
- Reverse osmosisOpen the method →
- Activated carbon (GAC)Open the method →
- Anion exchangeOpen the method →
9 products have a current certification naming a PFAS detected here.See PFAS filters, checked compound by compound ↓
Commercial · PFAS filters
Fit for Sammamish’s PFAS, compound by compound
Each filter is checked against the 6 PFAS detected here. A ✓ needs a current certification record that names the compound. A PFAS claim on the box is not enough.
As an Amazon Associate, PurityMap earns from qualifying purchases. A product appears here only when a current certification record covers at least one identified concern; every concern stays listed. The retail offer is looked up afterwards and never changes which products appear or their order. Affiliate disclosure.
- ✓Certified for this compound
- ?Claimed or likely, not established
- –No claim on record
Under-Sink Filter
Aquasana Claryum 2-Stage Under-Sink Filter (AQ-5200)
Activated Carbon (Claryum)Detected in Sammamish1 of 6 certified
- PFHxS16.5 ng/L–No claim on record
- PFOS11.1 ng/L✓Certified for this compound
- PFBS8.8 ng/L–No claim on record
- PFHxA4.3 ng/L–No claim on record
- PFPeA3.9 ng/L–No claim on record
- PFPeS4.1 ng/L–No claim on record
CertifiedNSF/ANSI 53 · PFOA, PFOS
Certified for PFOS; not established for PFHxS, PFBS, PFHxA, PFPeA, PFPeS.
Under-Sink Filter
Aquasana Claryum 3-Stage Max Flow Under-Sink Filter (AQ-6300M)
Activated Carbon (Claryum)Detected in Sammamish1 of 6 certified
- PFHxS16.5 ng/L–No claim on record
- PFOS11.1 ng/L✓Certified for this compound
- PFBS8.8 ng/L–No claim on record
- PFHxA4.3 ng/L–No claim on record
- PFPeA3.9 ng/L–No claim on record
- PFPeS4.1 ng/L–No claim on record
CertifiedNSF/ANSI 53 · PFOA, PFOSNSF/ANSI 42
Certified for PFOS; not established for PFHxS, PFBS, PFHxA, PFPeA, PFPeS.
Countertop System
Aquasana Clean Water Machine Countertop Filter (AQ-CWM2)
Activated Carbon (Claryum)Detected in Sammamish1 of 6 certified
- PFHxS16.5 ng/L–No claim on record
- PFOS11.1 ng/L✓Certified for this compound
- PFBS8.8 ng/L–No claim on record
- PFHxA4.3 ng/L–No claim on record
- PFPeA3.9 ng/L–No claim on record
- PFPeS4.1 ng/L–No claim on record
CertifiedNSF/ANSI 53 · PFOA, PFOSNSF/ANSI 42
Certified for PFOS; not established for PFHxS, PFBS, PFHxA, PFPeA, PFPeS.
Countertop System
Patriot Pure Ultimate Water Filtration System
Gravity pour-through (Nanomesh filter)Detected in Sammamish1 of 6 certified
- PFHxS16.5 ng/L–No claim on record
- PFOS11.1 ng/L✓Certified for this compound
- PFBS8.8 ng/L–No claim on record
- PFHxA4.3 ng/L–No claim on record
- PFPeA3.9 ng/L–No claim on record
- PFPeS4.1 ng/L–No claim on record
CertifiedNSF/ANSI 53 · PFOA, PFOS
Certified for PFOS; not established for PFHxS, PFBS, PFHxA, PFPeA, PFPeS.
Countertop System
AquaTru Carafe Countertop Reverse-Osmosis Purifier (AT100)
Reverse OsmosisDetected in Sammamish1 of 6 certified
- PFHxS16.5 ng/L–No claim on record
- PFOS11.1 ng/L✓Certified for this compound
- PFBS8.8 ng/L–No claim on record
- PFHxA4.3 ng/L–No claim on record
- PFPeA3.9 ng/L–No claim on record
- PFPeS4.1 ng/L–No claim on record
CertifiedNSF/ANSI 58NSF/ANSI 53 · PFOA, PFOSNSF/ANSI 42
Certified for PFOS; not established for PFHxS, PFBS, PFHxA, PFPeA, PFPeS.
Countertop System
AquaTru Classic Countertop Reverse-Osmosis Purifier (AT2000)
Reverse OsmosisDetected in Sammamish1 of 6 certified
- PFHxS16.5 ng/L–No claim on record
- PFOS11.1 ng/L✓Certified for this compound
- PFBS8.8 ng/L–No claim on record
- PFHxA4.3 ng/L–No claim on record
- PFPeA3.9 ng/L–No claim on record
- PFPeS4.1 ng/L–No claim on record
CertifiedNSF/ANSI 58NSF/ANSI 53 · PFOA, PFOSNSF/ANSI 42
Certified for PFOS; not established for PFHxS, PFBS, PFHxA, PFPeA, PFPeS.
Under-Sink Filter
Waterdrop G3P600 Tankless Reverse-Osmosis System
Reverse OsmosisDetected in Sammamish1 of 6 certified
- PFHxS16.5 ng/L–No claim on record
- PFOS11.1 ng/L✓Certified for this compound
- PFBS8.8 ng/L–No claim on record
- PFHxA4.3 ng/L–No claim on record
- PFPeA3.9 ng/L–No claim on record
- PFPeS4.1 ng/L–No claim on record
CertifiedNSF/ANSI 58NSF/ANSI 53 · PFOA, PFOSNSF/ANSI 42
Certified for PFOS; not established for PFHxS, PFBS, PFHxA, PFPeA, PFPeS.
Under-Sink Filter
Waterdrop G3P800 Tankless Reverse-Osmosis System
Reverse OsmosisDetected in Sammamish1 of 6 certified
- PFHxS16.5 ng/L–No claim on record
- PFOS11.1 ng/L✓Certified for this compound
- PFBS8.8 ng/L–No claim on record
- PFHxA4.3 ng/L–No claim on record
- PFPeA3.9 ng/L–No claim on record
- PFPeS4.1 ng/L–No claim on record
CertifiedNSF/ANSI 53 · PFOA, PFOSNSF/ANSI 58NSF/ANSI 42
Certified for PFOS; not established for PFHxS, PFBS, PFHxA, PFPeA, PFPeS.
Refrigerator Filter
Whirlpool Filter 3 Refrigerator Water Filter (WHR3RXD1)
Activated CarbonDetected in Sammamish1 of 6 certified
- PFHxS16.5 ng/L–No claim on record
- PFOS11.1 ng/L✓Certified for this compound
- PFBS8.8 ng/L–No claim on record
- PFHxA4.3 ng/L–No claim on record
- PFPeA3.9 ng/L–No claim on record
- PFPeS4.1 ng/L–No claim on record
CertifiedNSF/ANSI 53 · PFOA, PFOSNSF/ANSI 42NSF/ANSI 401
Certified for PFOS; not established for PFHxS, PFBS, PFHxA, PFPeA, PFPeS.
- Browse, not a match:
- Brita Elite Water Filter Pitcher
- Clearly Filtered Pitcher (lab-tested, not NSF 53 certified)
- Culligan ZeroWater 10-Cup Pitcher (ZEROP10)
- Frizzlife SP99 Under-Sink Filter
None of these is certified for all 6 compounds detected here. A tap test first tells you which ones reach your glass.
Questions
Frequently asked
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Is there PFAS in Sammamish tap water?
In EPA's UCMR 5 testing of SAMMAMISH PLATEAU WATER & SEWER (2023-05-15 to 2024-02-12): PFBS 8.8 ng/L (EPA health advisory 2,000), PFHxA 4.3 ng/L (state limit 400,000), PFHxS 16.5 ng/L (limit 10), PFOS 11.1 ng/L (limit 4), PFPeA 3.9 ng/L (no federal or state limit), PFPeS 4.1 ng/L (no federal or state limit) and the other 23 PFAS tested not detected. "Not detected" means below the lab's reporting limit, not proven zero.
What are the federal PFAS limits?
EPA's 2024 drinking-water rule set maximum contaminant levels of 4.0 ng/L for PFOA and for PFOS, and 10 ng/L for PFHxS, PFNA and HFPO-DA (GenX). In May 2026 EPA proposed keeping the PFOA and PFOS limits, with the option of until 2031 to comply, and rescinding the other three. Until a final rule, all five limits apply. Results above them today are above the limits in force.
How do I remove PFAS from my tap water?
Reverse-osmosis systems and filters certified to NSF/ANSI 53 or 58 for PFOA/PFOS reduction are the proven options at the tap. Check the certifier's listing (NSF, WQA or IAPMO) for the exact model, and replace cartridges on schedule.
- UCMR5 Analytical ResultsUCMR5 Analytical Results: SAMMAMISH PLATEAU WATER & SEWER (WA5340900)US EPA · 2026-01-15View source ↗
- State SDWIS Compliance RecordLead & Copper Rule 90th-percentile: SAMMAMISH PLATEAU WATER & SEWER (WA5340900)US EPA SDWIS · 2026-07-09View source ↗