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Buffalo County, SD Water Quality

Water quality data for 2 public water systems serving Buffalo County, South Dakota — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 2 water systems · 2 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

Buffalo County Earns a B

Buffalo County: 2 communities across 2 water systems. 100.0% have no open violations.

  • Median lead where detected: 2.33 ppb
  • 2 communities with a lead detection, 0 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 1 with significant inspection deficiencies
  • 100.0% of communities have no open violations
2.33 ppb
Median Lead Level
County-wide, 90th percentile
2
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
  • Gann Valley
    4.00 ppb
    No federal limits exceeded on record
    B
  • Fort Thompson
    0.66 ppb
    3 significant inspection deficiencies
    C
⚠ Needs Attention
  • Fort Thompson
    0.66 ppb
    3 significant inspection deficiencies
    C
  • Gann Valley
    4.00 ppb
    No federal limits exceeded on record
    B
County Lead Level — Median 2.33 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 2.33 ppb — 15.5% of the federal action level
Systems by Lead Level
Under 5 ppb
2

All Cities in Buffalo County

Fort Thompson 0.66 ppb C
Gann Valley 4.00 ppb B
Showing 2 cities
No active violations Active violations

About Buffalo County Drinking Water

Buffalo County is served by 2 water systems covering 2 communities. No community here has an open violation on record.

Of the communities reporting lead results, 2 recorded a detection, with a median of 2.33 ppb — 16% of the federal action level. 0 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 Buffalo County tap water safe to drink?▼
No community in Buffalo County has an open violation on record. No community has PFAS above the federal limit on record.
What is the lead level in Buffalo County?▼
Among communities with a detection the median is 2.33 ppb, 16% of the 15 ppb action level. 0 reported none detected and 0 reported no result.
How many water systems serve Buffalo County?▼
2 community water systems serve 2 communities here.
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