States › Washington › Snohomish County

Snohomish County, WA Water Quality

Water quality data for 32 public water systems serving Snohomish County, Washington — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 32 water systems · 63 cities
✅
Excellent — All Systems Performing Well

Water quality across the county is outstanding with minimal violations and very low lead levels.

A

Snohomish County Earns a A

Snohomish County: 63 communities across 32 water systems. 100.0% have no open violations.

  • Median lead where detected: 3.20 ppb
  • 47 communities with a lead detection, 4 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 25 with significant inspection deficiencies
  • 100.0% of communities have no open violations
3.2 ppb
Median Lead Level
County-wide, 90th percentile
32
Water Systems
Active CWS & NTNCWS
100%
Violation-Free
No active violations on record
How we grade counties: MyWaterIQ uses EPA SDWIS enforcement data — actual MCL violations and lead test results — not the aspirational MCLG targets used by some sites. A grade reflects real compliance history, not theoretical risk. Learn more →

Cities by Water Quality

⭐ Best Performing
  • Everett
    3.50 ppb
    No federal limits exceeded on record
    A
  • Marysville
    2.00 ppb
    No federal limits exceeded on record
    A
  • Lynnwood
    Not reported
    No federal limits exceeded on record
    B
  • Edmonds
    Not reported
    No federal limits exceeded on record
    B
  • Mountlake Terrace
    Not reported
    No federal limits exceeded on record
    B
⚠ Needs Attention
County Lead Level — Median 3.2 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 3.2 ppb — 21.3% of the federal action level
Systems by Lead Level
Under 5 ppb
34
5 – 10 ppb
2
10 – 15 ppb
11
No Data
16

All Cities in Snohomish County

Everett 3.50 ppb A
Marysville 2.00 ppb A
Lynnwood Not reported B
Lake Stevens 3.20 ppb A
Edmonds Not reported B
Bothell West 28.00 ppb C
Mountlake Terrace Not reported B
Silver Firs Not reported B
North Lynnwood 28.00 ppb C
Martha Lake 28.00 ppb C
Monroe Not reported B
Mill Creek East 28.00 ppb C
Eastmont Not reported B
Arlington Not detected A
Mukilteo Not reported B
Lake Stickney 28.00 ppb C
Bothell East 28.00 ppb C
Mill Creek Not reported B
Alderwood Manor 28.00 ppb C
Picnic Point 28.00 ppb C
Snohomish 0.80 ppb A
Maltby 3.10 ppb A
Stanwood 1.60 ppb A
Brier 28.00 ppb C
Cavalero 3.20 ppb A
Sultan 1.30 ppb A
Larch Way 28.00 ppb C
Woods Creek Not reported B
Esperance 1.70 ppb A
Lake Goodwin 1.00 ppb A
Bunk Foss 3.20 ppb A
Canyon Creek 3.20 ppb A
Meadowdale 28.00 ppb C
High Bridge 3.10 ppb A
Clearview 3.10 ppb A
Three Lakes Not reported B
Cathcart 3.10 ppb A
Lake Cassidy 3.20 ppb A
Fobes Hill 3.10 ppb A
Arlington Heights 3.20 ppb A
Chain Lake Not reported B
Granite Falls 3.00 ppb A
Lochsloy 3.20 ppb A
Gold Bar 1.20 ppb A
Warm Beach 1.80 ppb B
Monroe North Not reported B
Darrington 1.50 ppb B
Woodway 1.70 ppb A
Machias 3.20 ppb A
Sisco Heights 3.20 ppb A
Sunday Lake 1.00 ppb B
Lake Ketchum Not detected B
Bryant 5.70 ppb B
May Creek 1.30 ppb B
Lake Bosworth 3.20 ppb A
Startup Not detected B
Lake Roesiger 3.20 ppb A
Kayak Point 1.00 ppb A
North Sultan 1.30 ppb A
Index 6.60 ppb B
Northwest Stanwood 1.60 ppb A
Silvana 2.10 ppb B
Hat Island Not detected B
Showing 63 cities
No active violations Active violations

About Snohomish County Drinking Water

Snohomish County is served by 32 water systems covering 63 communities. No community here has an open violation on record.

Of the communities reporting lead results, 47 recorded a detection, with a median of 3.20 ppb — 21% of the federal action level. 4 reported none detected, which means below the laboratory limit rather than an absence of lead.

No community here has PFAS above the federal limit on record. State inspectors recorded significant deficiencies at 25 of them.

Frequently Asked Questions

Is Snohomish County tap water safe to drink?▼
No community in Snohomish County has an open violation on record. No community has PFAS above the federal limit on record.
What is the lead level in Snohomish County?▼
Among communities with a detection the median is 3.20 ppb, 21% of the 15 ppb action level. 4 reported none detected and 12 reported no result.
How many water systems serve Snohomish County?▼
32 community water systems serve 63 communities here.
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