Olney East Fork Lake
Richland County, WisconsinEutrophic
Olney East Fork Lake is a productive, nutrient-rich eutrophic lake in Richland County, IL. Water quality is graded C based on 2 sampling years through 2022. Compared to the 2 other monitored lakes in Richland County, Olney East Fork Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2022-10-31. Grade methodology: LakeGrade methodology.
Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
Very murky, less than 3.2 ft of visibility. Phosphorus level: 25.5 µg/L. Trophic State Index: 56.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.2 ft | F |
| Phosphorus | 25.5 µg/L | B |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 56 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Location
County Ranking
Ranked #1 of 3 lakes in Richland County
Nearby Lakes in Richland County
More Wisconsin Lake Rankings
Other Grade C Lakes in Wisconsin
Cook County · Clarity: 9 ft
Cook County · Clarity: 8.5 ft
Williamson County · Clarity: 3.2 ft
Johnson County · Clarity: 4.5 ft
Gallatin County · Clarity: 3.9 ft
Rock Island County · Clarity: 4.2 ft
Eutrophic Lakes in Wisconsin
EPA Impairment Status
Olney East Fork Lake 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 IL_RCC · Official waterbody report
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Most recent sample: 2022-10-31
Monitoring stations: 3