Boujan Swale Lake is a highly nutrient-loaded hypereutrophic lake in Cass County, Illinois. Water quality is graded F based on 1 sampling years through 2023. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Illinois DNR, last sampled 2023-07-18. 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. Chlorophyll-a: 136 µg/L. Trophic State Index: 79.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No data | |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 136 µg/L | F |
| Trophic State Index (TSI) | 79 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Where to stay near Boujan Swale Lake
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Fishing Boujan Swale Lake
Recreation & Access
Location
County Ranking
Ranked #1 of 1 lakes in Cass County
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Boujan Swale Lake holds Grade F. One nearby lake has a higher grade.
Nearby Lakes in Cass County
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Very high nutrients, dense algae, poor clarity
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Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth is a modeled estimate.
Regulated Pollution Sources Nearby
3 EPA-permitted facilities operate within about 5 miles of Boujan Swale Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 2 facilities have a reported Clean Water Act violation in the past three years.
- Beardstown Sd StpBeardstown · 3.5 mi away · NPDES IL0025135MajorRecent violation
- Cargill Meat Solutions CorporationBeardstown · 4.5 mi away · NPDES IL0023914Recent violation
- Osmose Casswood Site-BeardstwnBeardstown · 4.4 mi away · NPDES IL0069299
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Data Sources
Water quality data from the EPA Water Quality Portal
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Grading methodology based on Metropolitan Council standards
Public boat-access points from the USGS National Boat Ramps inventory
Most recent sample: 2023-07-18
Monitoring stations: 1