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Ada County, ID Water Quality

Water quality data for 5 public water systems serving Ada County, Idaho — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 5 water systems · 8 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

Ada County Earns a B

Ada County: 8 communities across 5 water systems. 100.0% have no open violations.

  • Median lead where detected: 2.00 ppb
  • 6 communities with a lead detection, 2 reporting none detected
  • 1 communities with PFAS above the federal limit
  • 6 with significant inspection deficiencies
  • 100.0% of communities have no open violations
2 ppb
Median Lead Level
County-wide, 90th percentile
5
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
  • Kuna
    Not detected
    No federal limits exceeded on record
    A
  • Star
    1.00 ppb
    No federal limits exceeded on record
    A
  • Meridian
    3.90 ppb
    1 significant inspection deficiency
    A
  • Boise City
    2.00 ppb
    4 significant inspection deficiencies
    B
  • Eagle
    2.00 ppb
    4 significant inspection deficiencies
    B
⚠ Needs Attention
  • Garden City
    Not detected
    PFAS above the limit at 1 of 8 sampling points
    D
  • Boise City
    2.00 ppb
    4 significant inspection deficiencies
    B
  • Eagle
    2.00 ppb
    4 significant inspection deficiencies
    B
  • Hidden Springs
    2.00 ppb
    4 significant inspection deficiencies
    B
  • Avimor
    2.00 ppb
    4 significant inspection deficiencies
    B
County Lead Level — Median 2 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 2 ppb — 13.3% of the federal action level
Systems by Lead Level
Under 5 ppb
6
No Data
2

All Cities in Ada County

Boise City 2.00 ppb B
Meridian 3.90 ppb A
Kuna Not detected A
Eagle 2.00 ppb B
Star 1.00 ppb A
Garden City Not detected D
Hidden Springs 2.00 ppb B
Avimor 2.00 ppb B
Showing 8 cities
No active violations Active violations

About Ada County Drinking Water

Ada County is served by 5 water systems covering 8 communities. No community here has an open violation on record.

Of the communities reporting lead results, 6 recorded a detection, with a median of 2.00 ppb — 13% of the federal action level. 2 reported none detected, which means below the laboratory limit rather than an absence of lead.

1 of 8 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 6 of them.

Frequently Asked Questions

Is Ada County tap water safe to drink?▼
No community in Ada County has an open violation on record. 1 of 8 have PFAS above the federal limit, which is the main open concern.
What is the lead level in Ada County?▼
Among communities with a detection the median is 2.00 ppb, 13% of the 15 ppb action level. 2 reported none detected and 0 reported no result.
How many water systems serve Ada County?▼
5 community water systems serve 8 communities here.
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