Parry Sound District County, Ontario · Water Quality Report Card
Oastler Lake
Oastler Lake in Parry Sound District, Ontario received a water quality grade of B (Good). Water clarity: 3 m visibility. Phosphorus: 7.1 µg/L.
- Clarity
- 3 m
- Type
- Oligotrophic
Oastler Lake is a cold, clear oligotrophic lake in Parry Sound District County, Ontario. Water quality is graded B based on 2 sampling years through 2025. Compared to the 230 other monitored lakes in Parry Sound District County, Oastler Lake ranks #169 for water quality.
Source: EPA Water Quality Portal sampling records, Ontario MECP, last sampled 2025-06-18. Grade methodology: LakeGrade methodology.
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Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Moderate clarity, visible to about 9.8 ft. Phosphorus level: 7.1 µg/L. Trophic State Index: 38.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3 m | C |
| Phosphorus | 7.1 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 38 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Oastler Lake
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Fishing Oastler Lake
Location
County Ranking
Ranked #169 of 231 lakes in Parry Sound District
Cleaner Lakes Within 30 Miles
Oastler Lake holds Grade B. 3 nearby lakes hold higher grades.
- ARichmond LakeParry Sound District · 2.1 mi · Higher grade (B → A)
- AOtter LakeParry Sound District · 1.6 mi · Higher grade (B → A)
- ABack LakeParry Sound District · 2.2 mi · Higher grade (B → A)
Nearby Lakes in Parry Sound District
Explore Oastler Lake across LakeGrade
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Other Grade B Lakes in Ontario
Oligotrophic Lakes in Ontario
More records, surveys & data sources
Where this data comes from
Measurements for Oastler 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: 2025-06-18
Monitoring stations: