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Nevada County, CA Water Quality

Water quality data for 12 public water systems serving Nevada County, California — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 12 water systems · 13 cities
✅
Excellent — All Systems Performing Well

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

A

Nevada County Earns a A

Nevada County: 13 communities across 12 water systems. 92.3% have no open violations.

  • Median lead where detected: 2.49 ppb
  • 10 communities with a lead detection, 3 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 1 with significant inspection deficiencies
  • 92.3% of communities have no open violations
2.49 ppb
Median Lead Level
County-wide, 90th percentile
12
Water Systems
Active CWS & NTNCWS
92%
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
  • Truckee
    3.90 ppb
    No federal limits exceeded on record
    A
  • Grass Valley
    Not detected
    No federal limits exceeded on record
    B
  • Alta Sierra
    0.77 ppb
    No federal limits exceeded on record
    B
  • Lake Wildwood
    0.56 ppb
    No federal limits exceeded on record
    A
  • Lake of the Pines
    1.08 ppb
    No federal limits exceeded on record
    A
⚠ Needs Attention
  • Washington
    41.40 ppb
    Lead above the 15 ppb action level
    F
  • Kingvale
    12.20 ppb
    1 significant inspection deficiency
    B
  • North San Juan
    10.10 ppb
    Lead at 10.10 ppb, above a third of the action level
    B
  • Nevada City
    0.90 ppb
    1 health-based violation since 2015
    B
  • Soda Springs
    4.65 ppb
    1 health-based violation since 2015
    B
County Lead Level — Median 2.49 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 2.49 ppb — 16.6% of the federal action level
Systems by Lead Level
Under 5 ppb
7
10 – 15 ppb
3
No Data
3

All Cities in Nevada County

Truckee 3.90 ppb A
Grass Valley Not detected B
Alta Sierra 0.77 ppb B
Lake Wildwood 0.56 ppb A
Lake of the Pines 1.08 ppb A
Nevada City 0.90 ppb B
Penn Valley 0.56 ppb A
Rough and Ready Not detected B
North San Juan 10.10 ppb B
Washington 41.40 ppb F
Kingvale 12.20 ppb B
Soda Springs 4.65 ppb B
Floriston Not detected B
Showing 13 cities
No active violations Active violations

About Nevada County Drinking Water

Nevada County is served by 12 water systems covering 13 communities. 92% have no open violations.

Of the communities reporting lead results, 10 recorded a detection, with a median of 2.49 ppb — 17% of the federal action level. 3 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 1 of them.

Frequently Asked Questions

Is Nevada County tap water safe to drink?▼
92% of communities have no open violation. No community has PFAS above the federal limit on record.
What is the lead level in Nevada County?▼
Among communities with a detection the median is 2.49 ppb, 17% of the 15 ppb action level. 3 reported none detected and 0 reported no result.
How many water systems serve Nevada County?▼
12 community water systems serve 13 communities here.
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