Whatcom County Water Quality: 4 Cities Ranked by the Records

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

Whatcom County, Washington: 4 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 Whatcom 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.

Lead (90th percentile)Detected in 4 systems15 µg/L federal action level · US EPAHighest5.6 µg/L

FERNDALE5.6 µg/LMonitoring period: 2022–2024
BELLINGHAM-WATER DIVISION CITY OF3.4 µg/LMonitoring period: 2021–2023
LYNDEN WATER DEPARTMENT2.3 µg/LMonitoring period: 2021–2023
BIRCH BAY WATER & SEWER DISTRICT1.8 µg/LMonitoring period: 2023–2025

Water hardnessDetected in 1 systemAesthetic, no federal health limit · USGSHighest1.3 gpg

BELLINGHAM-WATER DIVISION CITY OF1.3 gpgReporting year: 2025

30 substances tested, none detected in any systemShow

Tested in these 4 systems: BELLINGHAM-WATER DIVISION CITY OF, BIRCH BAY WATER & SEWER DISTRICT, FERNDALE, LYNDEN WATER DEPARTMENT

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)
1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 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)
Lithium
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)
Perfluorooctanesulfonic acid (PFOS)
Perfluorooctanoic acid (PFOA)
Perfluoropentanesulfonic acid (PFPeS)
Perfluoropentanoic acid (PFPeA)
Perfluorotetradecanoic acid (PFTA)
Perfluorotridecanoic acid (PFTrDA)
Perfluoroundecanoic acid (PFUnA)

4 cities

Cities ranked by the records

1
Birch BayBIRCH BAY WATER & SEWER DISTRICT
No PFAS detectedLead below action level
Open city report →
2
BellinghamBELLINGHAM-WATER DIVISION CITY OF
No PFAS detectedLead below action level
Open city report →
3
LyndenLYNDEN WATER DEPARTMENT
No PFAS detectedLead below action level
Open city report →
4
FerndaleFERNDALE
No PFAS detectedLead below action level
Open city report →

Showing 4 of 4 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 Whatcom CountyPFAS detected in 0 of 4 cities; none had a sample above a 2024 EPA limit

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

Lead

0of 4 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 Washington

Hard water

1city reports hardness · Bellingham, 1.3 gpg

None above 7 gpg, the USGS threshold for hard water. An aesthetic measure with no federal health limit.

Hard water explained

Who supplies the county

Largest water systems

BellinghamBELLINGHAM-WATER DIVISION CITY OF · WA5305600
141,127 served
LyndenLYNDEN WATER DEPARTMENT · WA5349150
20,062 served
FerndaleFERNDALE · WA5324850
19,305 served
Birch BayBIRCH BAY WATER & SEWER DISTRICT · WA5395904
9,046 served

Questions

Frequently asked

How does Whatcom County tap water compare across cities?

PurityMap ranks 4 cities in Whatcom 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 Birch Bay's main water system: BIRCH BAY WATER & SEWER DISTRICT · PWSID WA5395904 · Purity Score 98 (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 Whatcom County cities had a PFAS sample above a 2024 EPA limit?

None of the 4 Whatcom County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing. PFAS were detected below the limit in 0.

Is there lead in Whatcom County tap water?

Utilities report lead as a 90th-percentile result from home taps. 4 of 4 Whatcom 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.

Does Whatcom County have hard water?

Hardness is published in utility water-quality reports for 1 Whatcom County city on record; the hardest is Bellingham at 1.3 grains per gallon. Hardness affects scale and appliances; it is not a health finding.

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