Leeds and Grenville Counties County, Ontario · Water Quality Report Card
St Lawrence River Lake
St Lawrence River Lake in Leeds and Grenville Counties, Ontario received a water quality grade of A (Excellent). Water clarity: 9.5 m visibility. Phosphorus: 10.1 µg/L.
- Clarity
- 9.5 m
- Type
- Oligotrophic
St Lawrence River Lake is a cold, clear oligotrophic lake in Leeds and Grenville Counties County, Ontario. Water quality is graded A based on 2 sampling years through 2010. Compared to the 33 other monitored lakes in Leeds and Grenville Counties County, St Lawrence River Lake ranks #10 for water quality.
Source: EPA Water Quality Portal sampling records, Ontario MECP, last sampled 2010-11-02. Grade methodology: LakeGrade methodology.
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Crystal clear, you can see 31.2 ft down. Phosphorus level: 10.1 µg/L. Trophic State Index: 33.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 9.5 m | A |
| Phosphorus | 10.1 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 33 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
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Fishing St Lawrence River Lake
Location
County Ranking
Ranked #10 of 34 lakes in Leeds and Grenville Counties
Nearby Lakes in Leeds and Grenville Counties
Explore St Lawrence River Lake across LakeGrade
More Ontario Lake Rankings
Other Grade A Lakes in Ontario
Oligotrophic Lakes in Ontario
More records, surveys & data sources
Where this data comes from
Measurements for St Lawrence River 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: 2010-11-02
Monitoring stations: