Clackamas County Water Quality: 9 Cities Ranked by the Records

Name: Clackamas County Water Quality Data (2026)
Creator: PurityMap
License: https://creativecommons.org/licenses/by/4.0/

Clackamas County, Oregon: 9 city reports built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.

Find my system Open on the map Private wells in Clackamas County

Across the county's systems

Highest result for each contaminant

One row per contaminant: the highest result any system in the county reported, against its limit. Open a row for the systems behind it.

LithiumDetected in 1 system of 9 tested10 µg/L EPA health reference level (screening, not a legal limit) · US EPAHighest58.2 µg/L

SUNRISE WATER AUTHORITY58.2 µg/LSample date: 2024-12-11 to 2025-09-23
CANBY UTILITYNot detected · below 9.0 µg/L lab reporting limitSample date: 2023-07-10 to 2024-04-09
GLADSTONE, CITY OFNot detected · below 9.0 µg/L lab reporting limitSample date: 2023-10-02 to 2025-12-17
LAKE OSWEGO MUNICIPAL WATERNot detected · below 9.0 µg/L lab reporting limitSample date: 2023-11-08 to 2024-07-31
MOLALLA, CITY OFNot detected · below 9.0 µg/L lab reporting limitSample date: 2023-01-10 to 2023-10-03
OREGON CITYNot detected · below 9.0 µg/L lab reporting limitSample date: 2024-01-02 to 2024-10-09
SANDY, CITY OFNot detected · below 9.0 µg/L lab reporting limitSample date: 2024-06-24 to 2025-03-12
WEST LINN, CITY OFNot detected · below 9.0 µg/L lab reporting limitSample date: 2023-08-17 to 2024-05-21
WILSONVILLE, CITY OFNot detected · below 9.0 µg/L lab reporting limitSample date: 2024-12-02 to 2025-09-03

Perfluorooctanesulfonic acid (PFOS)Detected in 1 system of 9 tested4.0 ng/L federal MCL (2024) · US EPAHighest4.3 ng/L

SUNRISE WATER AUTHORITY4.3 ng/LSample date: 2024-12-11 to 2025-09-23
CANBY UTILITYNot detected · below 4.0 ng/L lab reporting limitSample date: 2023-10-03 to 2024-04-09
GLADSTONE, CITY OFNot detected · below 4.0 ng/L lab reporting limitSample date: 2023-10-02 to 2025-12-17
LAKE OSWEGO MUNICIPAL WATERNot detected · below 4.0 ng/L lab reporting limitSample date: 2023-11-08 to 2024-07-31
MOLALLA, CITY OFNot detected · below 4.0 ng/L lab reporting limitSample date: 2023-01-10 to 2023-10-03
OREGON CITYNot detected · below 4.0 ng/L lab reporting limitSample date: 2024-01-02 to 2024-10-09
SANDY, CITY OFNot detected · below 4.0 ng/L lab reporting limitSample date: 2024-06-24 to 2025-03-12
WEST LINN, CITY OFNot detected · below 4.0 ng/L lab reporting limitSample date: 2023-08-17 to 2024-05-21
WILSONVILLE, CITY OFNot detected · below 4.0 ng/L lab reporting limitSample date: 2024-12-02 to 2025-09-03

Lead (90th percentile)Detected in 9 systems15 µg/L federal action level · US EPAHighest7.6 µg/L

WILSONVILLE, CITY OF7.6 µg/LMonitoring period: 2022–2024
GLADSTONE, CITY OF5.2 µg/LMonitoring period: 2024–2026 (still open)
SANDY, CITY OF4.14 µg/LMonitoring period: 2023–2025
SUNRISE WATER AUTHORITY3 µg/LMonitoring period: 2021–2023
CANBY UTILITY2.1 µg/LMonitoring period: 2022–2024
OREGON CITY1.84 µg/LMonitoring period: 2022–2024
WEST LINN, CITY OF1.84 µg/LMonitoring period: 2022–2024
LAKE OSWEGO MUNICIPAL WATER1.8 µg/LMonitoring period: 2024–2026 (still open)
MOLALLA, CITY OF1.26 µg/LMonitoring period: 2022–2024

1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)Detected in 1 system of 9 testedNo federal or state limit; shown for transparencyHighest11.3 ng/L

MOLALLA, CITY OF11.3 ng/LSample date: 2023-01-10 to 2023-10-03
CANBY UTILITYNot detected · below 5.0 ng/L lab reporting limitSample date: 2023-10-03 to 2024-04-09
GLADSTONE, CITY OFNot detected · below 5.0 ng/L lab reporting limitSample date: 2023-10-02 to 2025-12-17
LAKE OSWEGO MUNICIPAL WATERNot detected · below 5.0 ng/L lab reporting limitSample date: 2023-11-08 to 2024-07-31
OREGON CITYNot detected · below 5.0 ng/L lab reporting limitSample date: 2024-01-02 to 2024-10-09
SANDY, CITY OFNot detected · below 5.0 ng/L lab reporting limitSample date: 2024-06-24 to 2025-03-12
SUNRISE WATER AUTHORITYNot detected · below 5.0 ng/L lab reporting limitSample date: 2024-12-11 to 2025-09-23
WEST LINN, CITY OFNot detected · below 5.0 ng/L lab reporting limitSample date: 2023-08-17 to 2024-05-21
WILSONVILLE, CITY OFNot detected · below 5.0 ng/L lab reporting limitSample date: 2024-12-02 to 2025-09-03

27 PFAS tested, none detected in any systemShow

Tested in these 9 systems: CANBY UTILITY, GLADSTONE, CITY OF, LAKE OSWEGO MUNICIPAL WATER, MOLALLA, CITY OF, OREGON CITY, SANDY, CITY OF, SUNRISE WATER AUTHORITY, WEST LINN, CITY OF, WILSONVILLE, CITY OF

11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)
1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)
1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)
4,8-Dioxa-3H-perfluorononanoic acid (ADONA)
9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)
Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)
N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)
N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)
Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)
Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)
Perfluoro-3-methoxypropanoic acid (PFMPA)
Perfluoro-4-methoxybutanoic acid (PFMBA)
Perfluorobutanesulfonic acid (PFBS)
Perfluorobutanoic acid (PFBA)
Perfluorodecanoic acid (PFDA)
Perfluorododecanoic acid (PFDoA)
Perfluoroheptanesulfonic acid (PFHpS)
Perfluoroheptanoic acid (PFHpA)
Perfluorohexanesulfonic acid (PFHxS)
Perfluorohexanoic acid (PFHxA)
Perfluorononanoic acid (PFNA)
Perfluorooctanoic acid (PFOA)
Perfluoropentanesulfonic acid (PFPeS)
Perfluoropentanoic acid (PFPeA)
Perfluorotetradecanoic acid (PFTA)
Perfluorotridecanoic acid (PFTrDA)
Perfluoroundecanoic acid (PFUnA)

9 cities

Cities ranked by the records

1
MolallaMOLALLA, CITY OF
PFAS detected, within limitLead below action level
Open city report →
2
Lake OswegoLAKE OSWEGO MUNICIPAL WATER
No PFAS detectedLead below action level
Open city report →
3
Oregon CityOREGON CITY
No PFAS detectedLead below action level
Open city report →
4
West LinnWEST LINN, CITY OF
No PFAS detectedLead below action level
Open city report →
5
CanbyCANBY UTILITY
No PFAS detectedLead below action level
Open city report →
6
WilsonvilleWILSONVILLE, CITY OF
No PFAS detectedLead below action level
Open city report →
7
GladstoneGLADSTONE, CITY OF
No PFAS detectedLead below action level
Open city report →
8
SandySANDY, CITY OF
No PFAS detectedLead below action level
Open city report →
9
Happy ValleySUNRISE WATER AUTHORITY
PFAS sample above a limitLead below action level
Open city report →

Showing 6 of 9 cities · scores are system-level, not tap tests

Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no county score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works.

PFAS in Clackamas County1 of 9 city reports had a PFAS sample above a 2024 EPA limit

Happy Valley4.3 ng/L

4.0 ng/L federal MCL · PFOS, ng/LPFAS in Oregon

Lead

0of 9 cities above the 15 µg/L action level

Based on each system's 90th-percentile result. Lead from household plumbing isn't in this record.

Lead in Oregon

Who supplies the county

Largest water systems

Happy ValleySUNRISE WATER AUTHORITY · OR4100635
50,003 served
Lake OswegoLAKE OSWEGO MUNICIPAL WATER · OR4100457
40,000 served
Oregon CityOREGON CITY · OR4101511
33,940 served
West LinnWEST LINN, CITY OF · OR4100944
28,000 served
WilsonvilleWILSONVILLE, CITY OF · OR4100954
25,915 served
CanbyCANBY UTILITY · OR4100157
18,754 served
SandySANDY, CITY OF · OR4100789
12,991 served
GladstoneGLADSTONE, CITY OF · OR4100321
12,121 served
MolallaMOLALLA, CITY OF · OR4100534
10,298 served

Questions

Frequently asked

How does Clackamas County tap water compare across cities?

PurityMap ranks 9 cities in Clackamas County by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is Molalla's main water system: MOLALLA, CITY OF · PWSID OR4100534 · Purity Score 99 (Excellent) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.

How many Clackamas County cities had a PFAS sample above a 2024 EPA limit?

1 of 9 Clackamas County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing, including Happy Valley (PFOS 4.3 ng/L). That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation. PFAS were detected at any level in 2.

Is there lead in Clackamas County tap water?

Utilities report lead as a 90th-percentile result from home taps. 9 of 9 Clackamas County cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.

Next step

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