Thunder Bay District County, Ontario · Water Quality Report Card
Athelstane Lake
Athelstane Lake in Thunder Bay District, Ontario received a water quality grade of A (Excellent). Phosphorus: 12.1 µg/L.
- Type
- Mesotrophic
Athelstane Lake is a mesotrophic lake in Thunder Bay District County, Ontario. Water quality is graded A based on 1 sampling years through 2025. Compared to the 301 other monitored lakes in Thunder Bay District County, Athelstane Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Ontario MECP, last sampled 2025-05-23. Grade methodology: LakeGrade methodology.
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
No clarity data. Phosphorus level: 12.1 µg/L. Trophic State Index: 40.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No data | |
| Phosphorus | 12.1 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 40 | Mesotrophic |
Moderate nutrients, good water quality
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Fishing Athelstane Lake
Location
County Ranking
Ranked #2 of 302 lakes in Thunder Bay District
Nearby Lakes in Thunder Bay District
Explore Athelstane Lake across LakeGrade
More Ontario Lake Rankings
Other Grade A Lakes in Ontario
Mesotrophic Lakes in Ontario
More records, surveys & data sources
Where this data comes from
Measurements for Athelstane Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.
Data Sources
Water quality data from the EPA Water Quality Portal
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion
Most recent sample: 2025-05-23
Monitoring stations: