Malheur Lake is a highly nutrient-loaded hypereutrophic lake in Harney County, Oregon. Water quality is graded F based on 2 sampling years through 2023.
Source: EPA Water Quality Portal sampling records, Oregon DNR, last sampled 2023-07-24. 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
No clarity data. Phosphorus level: 807.5 µg/L. Chlorophyll-a: 45.5 µg/L. Trophic State Index: 84.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No data | |
| Phosphorus | 807.5 µg/L | F |
| Chlorophyll-a (Algae) | 45.5 µg/L | F |
| Trophic State Index (TSI) | 84 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
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Location
County Ranking
Ranked #1 of 1 lakes in Harney County
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More records, surveys & data sources
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2023-07-24
Monitoring stations: 13