Perry County, Ohio · Water Quality Report Card
Somerset Reservoir
Somerset Reservoir in Perry County, Ohio has a water quality grade of F (Very Poor). Phosphorus: 41.7 µg/L. Chlorophyll-a (algae): 63.5 µg/L.
- Type
- Hypereutrophic
Somerset Reservoir is a highly nutrient-loaded hypereutrophic lake in Perry County, Ohio. Water quality is graded F based on 2 sampling years through 2022. Compared to the 2 other monitored lakes in Perry County, Somerset Reservoir ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Ohio EPA, last sampled 2022-10-17. 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: 41.7 µg/L. Chlorophyll-a: 63.5 µg/L. Trophic State Index: 65.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No data | |
| Phosphorus | 41.7 µg/L | Poor |
| Chlorophyll-a (Algae) | 63.5 µg/L | Poor |
| Trophic State Index (TSI) | 65 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Where to stay near Somerset Reservoir
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Fishing Somerset Reservoir
Location
County Ranking
Ranked #2 of 3 lakes in Perry County
Nearby Lakes in Perry County
Explore Somerset Reservoir across LakeGrade
More Ohio Lake Rankings
Other Grade F Lakes in Ohio
Hypereutrophic Lakes in Ohio
More records, surveys & data sources
EPA Impairment Status
Somerset Reservoir is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit OH050302040101 · Official waterbody report · Matched by proximity (1.73 km)
Where this data comes from
29 measurements from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Division of Surface water (Ohio)
21OHIO_WQX29 samples · 2022
Analytical methods
- Total Phosphorus After Block Digestion
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- 2130 B ~ Nephelometric Method
Monitoring station identifiers (1)
Grade thresholds come from the U.S. EPA National Lakes Assessment 2022 Technical Support Document (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated.
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion
Most recent sample: 2022-10-17
Monitoring stations: 1