Simpson Park Lake
St. Louis County, WisconsinEutrophic
Simpson Park Lake is a productive, nutrient-rich eutrophic lake in St. Louis County, MO. Water quality is graded D based on 3 sampling years through 2024. Compared to the 8 other monitored lakes in St. Louis County, Simpson Park Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-09-20. Grade methodology: LakeGrade methodology.
Swimming Safety
Swimming not recommended, poor water quality with high algae risk
Water Quality Grade: D, Poor
Very murky, less than 1.8 ft of visibility. Phosphorus level: 73 µg/L. Chlorophyll-a: 23.3 µg/L. Trophic State Index: 65.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.8 ft | F |
| Phosphorus | 73 µg/L | D |
| Chlorophyll-a (Algae) | 23.3 µg/L | D |
| Trophic State Index (TSI) | 65 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Location
County Ranking
Ranked #1 of 9 lakes in St. Louis County
Cleaner Lakes Within 30 Miles
Simpson Park Lake holds Grade D. One nearby lake has a higher grade.
See full comparison →Nearby Lakes in St. Louis County
More Wisconsin Lake Rankings
Other Grade D Lakes in Wisconsin
St. Louis city County · Clarity: 2.3 ft
Shelby County · Clarity: 3.2 ft
Macon County · Clarity: 1.8 ft
Harrison County · Clarity: 1.7 ft
Stone County · Clarity: 2.3 ft
Knox County · Clarity: 2.1 ft
Eutrophic Lakes in Wisconsin
EPA Impairment Status
Simpson Park Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MO_7502.00 · 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: 2024-09-20
Monitoring stations: 1