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Lewis County, WA Water Quality

Water quality data for 11 public water systems serving Lewis County, Washington — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 11 water systems · 12 cities
✅
Excellent — All Systems Performing Well

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

A

Lewis County Earns a A

Lewis County: 12 communities across 11 water systems. 100.0% have no open violations.

  • Median lead where detected: 2.40 ppb
  • 7 communities with a lead detection, 5 reporting none detected
  • 2 communities with PFAS above the federal limit
  • 0 with significant inspection deficiencies
  • 100.0% of communities have no open violations
2.4 ppb
Median Lead Level
County-wide, 90th percentile
11
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
  • Chehalis
    Not detected
    No federal limits exceeded on record
    B
  • Winlock
    2.40 ppb
    No federal limits exceeded on record
    B
  • Morton
    2.40 ppb
    No federal limits exceeded on record
    B
  • Mossyrock
    2.00 ppb
    No federal limits exceeded on record
    B
  • Toledo
    4.00 ppb
    No federal limits exceeded on record
    B
⚠ Needs Attention
  • Centralia
    Not detected
    PFAS above the limit at 2 of 3 sampling points
    C
  • Fords Prairie
    Not detected
    PFAS above the limit at 2 of 3 sampling points
    C
  • Pe Ell
    Not detected
    Copper above the 1,300 ppb action level
    C
  • Napavine
    3.00 ppb
    Copper above the 1,300 ppb action level
    B
  • Vader
    1.00 ppb
    2 health-based violations since 2015
    B
County Lead Level — Median 2.4 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 2.4 ppb — 16% of the federal action level
Systems by Lead Level
Under 5 ppb
7
No Data
5

All Cities in Lewis County

Centralia Not detected C
Chehalis Not detected B
Fords Prairie Not detected C
Napavine 3.00 ppb B
Winlock 2.40 ppb B
Morton 2.40 ppb B
Mossyrock 2.00 ppb B
Pe Ell Not detected C
Toledo 4.00 ppb B
Vader 1.00 ppb B
Onalaska Not detected B
Packwood 2.50 ppb B
Showing 12 cities
No active violations Active violations

About Lewis County Drinking Water

Lewis County is served by 11 water systems covering 12 communities. No community here has an open violation on record.

Of the communities reporting lead results, 7 recorded a detection, with a median of 2.40 ppb — 16% of the federal action level. 5 reported none detected, which means below the laboratory limit rather than an absence of lead.

2 of 12 communities have PFAS above the limits EPA set in 2024, measured as a running annual average at each sampling point. State inspectors recorded no significant deficiencies.

Frequently Asked Questions

Is Lewis County tap water safe to drink?▼
No community in Lewis County has an open violation on record. 2 of 12 have PFAS above the federal limit, which is the main open concern.
What is the lead level in Lewis County?▼
Among communities with a detection the median is 2.40 ppb, 16% of the 15 ppb action level. 5 reported none detected and 0 reported no result.
How many water systems serve Lewis County?▼
11 community water systems serve 12 communities here.
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