Thunder Bay District County, Ontario · Water Quality Report Card
Cox Lake
Cox Lake in Thunder Bay District, Ontario received a water quality grade of D (Poor). Water clarity: 0.6 m visibility. Phosphorus: 51.3 µg/L.
- Clarity
- 0.6 m
- Type
- Eutrophic
Cox Lake is a productive, nutrient-rich eutrophic lake in Thunder Bay District County, Ontario. Water quality is graded D based on 2 sampling years through 2012. Compared to the 301 other monitored lakes in Thunder Bay District County, Cox Lake ranks #293 for water quality.
Source: EPA Water Quality Portal sampling records, Ontario MECP, last sampled 2012-08-14. Grade methodology: LakeGrade methodology.
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Swimming Safety
Swimming not recommended, poor water quality with high algae risk
Water Quality Grade: D, Poor
Very murky, less than 2 ft of visibility. Phosphorus level: 51.3 µg/L. Trophic State Index: 64.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 0.6 m | F |
| Phosphorus | 51.3 µg/L | C |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 64 | Eutrophic |
High nutrients, frequent algae, reduced clarity
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Fishing Cox Lake
Location
County Ranking
Ranked #293 of 302 lakes in Thunder Bay District
Cleaner Lakes Within 30 Miles
Cox Lake holds Grade D. 4 nearby lakes hold higher grades.
- AFrazer L. LakeThunder Bay District · 8.1 mi · Two grade letters higher (D → A)
- ALake NipigonThunder Bay District · 14.5 mi · Two grade letters higher (D → A)
- BOskawe LakeThunder Bay District · 4.7 mi · Two grade letters higher (D → B)
- BPurdom L. LakeThunder Bay District · 9 mi · Two grade letters higher (D → B)
Nearby Lakes in Thunder Bay District
Explore Cox Lake across LakeGrade
More Ontario Lake Rankings
Other Grade D Lakes in Ontario
Eutrophic Lakes in Ontario
More records, surveys & data sources
Where this data comes from
Measurements for Cox 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: 2012-08-14
Monitoring stations: