States › California › Mendocino County

Mendocino County, CA Water Quality

Water quality data for 18 public water systems serving Mendocino County, California — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 18 water systems · 18 cities
✅
Generally Safe — Most Systems Performing Well

The majority of water systems have no active violations and lead levels well below the federal action level.

B

Mendocino County Earns a B

Mendocino County: 18 communities across 18 water systems. 83.3% have no open violations.

  • Median lead where detected: 5.00 ppb
  • 5 communities with a lead detection, 13 reporting none detected
  • 1 communities with PFAS above the federal limit
  • 3 with significant inspection deficiencies
  • 83.3% of communities have no open violations
5 ppb
Median Lead Level
County-wide, 90th percentile
18
Water Systems
Active CWS & NTNCWS
83%
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
  • Brooktrails
    Not detected
    No federal limits exceeded on record
    A
  • Redwood Valley
    Not detected
    No federal limits exceeded on record
    A
  • Calpella
    Not detected
    No federal limits exceeded on record
    B
  • Anchor Bay
    Not detected
    No federal limits exceeded on record
    B
  • Cleone
    Not detected
    No federal limits exceeded on record
    B
⚠ Needs Attention
  • Covelo
    5.00 ppb
    1 violation currently open
    F
  • Little River
    5.00 ppb
    Copper above the 1,300 ppb action level
    D
  • Laytonville
    5.00 ppb
    Copper above the 1,300 ppb action level
    D
  • Fort Bragg
    Not detected
    Copper above the 1,300 ppb action level
    D
  • Talmage
    Not detected
    Copper above the 1,300 ppb action level
    D
County Lead Level — Median 5 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 5 ppb — 33.3% of the federal action level
Systems by Lead Level
Under 5 ppb
1
5 – 10 ppb
3
10 – 15 ppb
1
No Data
13

All Cities in Mendocino County

Ukiah Not detected B
Fort Bragg Not detected D
Willits Not detected B
Brooktrails Not detected A
Redwood Valley Not detected A
Talmage Not detected D
Hopland Not detected B
Calpella Not detected B
Anchor Bay Not detected B
Point Arena Not detected B
Cleone Not detected B
Laytonville 5.00 ppb D
Mendocino 16.00 ppb C
Covelo 5.00 ppb F
Boonville Not detected B
Caspar 2.70 ppb B
Albion Not detected B
Little River 5.00 ppb D
Showing 18 cities
No active violations Active violations

About Mendocino County Drinking Water

Mendocino County is served by 18 water systems covering 18 communities. 83% have no open violations.

Of the communities reporting lead results, 5 recorded a detection, with a median of 5.00 ppb — 33% of the federal action level. 13 reported none detected, which means below the laboratory limit rather than an absence of lead.

1 of 18 communities have PFAS above the limits EPA set in 2024, measured as a running annual average at each sampling point. State inspectors recorded significant deficiencies at 3 of them.

Frequently Asked Questions

Is Mendocino County tap water safe to drink?▼
83% of communities have no open violation. 1 of 18 have PFAS above the federal limit, which is the main open concern.
What is the lead level in Mendocino County?▼
Among communities with a detection the median is 5.00 ppb, 33% of the 15 ppb action level. 13 reported none detected and 0 reported no result.
How many water systems serve Mendocino County?▼
18 community water systems serve 18 communities here.
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