Le Val-Saint-François County, Québec · Water Quality Report Card
Petit Lac Saint-FrançOis
Petit Lac Saint-FrançOis in Le Val-Saint-François, Québec received a water quality grade of F (Very Poor). Water clarity: 0.7 m visibility. Phosphorus: 161.1 µg/L. Chlorophyll-a (algae): 77.8 µg/L.
- Clarity
- 0.7 m
- Type
- Hypereutrophic
Petit Lac Saint-FrançOis is a highly nutrient-loaded hypereutrophic lake in Le Val-Saint-François County, Québec. Water quality is graded F based on 3 sampling years through 2025. Compared to the 9 other monitored lakes in Le Val-Saint-François County, Petit Lac Saint-FrançOis ranks #10 for water quality.
Source: EPA Water Quality Portal sampling records, MELCCFP, last sampled 2025-08-01. Grade methodology: LakeGrade methodology.
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Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 2.3 ft of visibility. Phosphorus level: 161.1 µg/L. Chlorophyll-a: 77.8 µg/L. Trophic State Index: 72.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 0.7 m | F |
| Phosphorus | 161.1 µg/L | F |
| Chlorophyll-a (Algae) | 77.8 µg/L | F |
| Trophic State Index (TSI) | 72 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Where to stay near Petit Lac Saint-FrançOis
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Fishing Petit Lac Saint-FrançOis
Location
County Ranking
Ranked #10 of 10 lakes in Le Val-Saint-François
Cleaner Lakes Within 30 Miles
Petit Lac Saint-FrançOis holds Grade F. 5 nearby lakes hold higher grades.
- APetit Lac BromptonLe Val-Saint-François · 6.8 mi · Two grade letters higher (F → A)
- ALac MontjoieLe Val-Saint-François · 9.2 mi · Two grade letters higher (F → A)
- ALac BromptonMemphrémagog · 9.3 mi · Two grade letters higher (F → A)
- BLac DesmaraisLe Val-Saint-François · 7 mi · Two grade letters higher (F → B)
- BLac MillerLe Val-Saint-François · 8 mi · Two grade letters higher (F → B)
Nearby Lakes in Le Val-Saint-François
Explore Petit Lac Saint-FrançOis across LakeGrade
More Québec Lake Rankings
Other Grade F Lakes in Québec
Hypereutrophic Lakes in Québec
More records, surveys & data sources
Where this data comes from
Measurements for Petit Lac Saint-FrançOis 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: 2025-08-01
Monitoring stations: