Union County, Ohio · Water Quality Report Card
Marysville Upground Reservoir
Marysville Upground Reservoir in Union County, Ohio has a water quality grade of A (Excellent). Phosphorus: 39.7 µg/L. Chlorophyll-a (algae): 6.2 µg/L.
- Type
- Mesotrophic
Marysville Upground Reservoir is a mesotrophic lake in Union County, Ohio. Water quality is graded A based on 1 sampling years through 2024.
Source: EPA Water Quality Portal sampling records, Ohio EPA, last sampled 2024-08-13. Grade methodology: LakeGrade methodology.
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
No clarity data. Phosphorus level: 39.7 µg/L. Chlorophyll-a: 6.2 µg/L. Trophic State Index: 53.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No data | |
| Phosphorus | 39.7 µg/L | |
| Chlorophyll-a (Algae) | 6.2 µg/L | Good |
| Trophic State Index (TSI) | 53 | Mesotrophic |
Moderate nutrients, good water quality
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Fishing Marysville Upground Reservoir
Location
County Ranking
Ranked #1 of 1 lakes in Union County
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More records, surveys & data sources
Where this data comes from
18 measurements from 1 monitoring station, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Division of Surface water (Ohio)
21OHIO_WQX18 samples · 2024
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
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion
Most recent sample: 2024-08-13
Monitoring stations: 1