Slm Side Channel Lake
St. Clair County, IllinoisView mapDirections
Illinois EPA publishes the water-quality measurements for Slm Side Channel Lake. Here is what has been measured.
- Hypereutrophic
- Limited data
Slm Side Channel Lake in St. Clair County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Water clarity: 0.8 ft visibility. Phosphorus: 317 µg/L. Chlorophyll-a (algae): 95.6 µg/L.
Slm Side Channel Lake is a highly nutrient-loaded hypereutrophic lake in St. Clair County, Illinois.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2021-10-25. Methodology: how these readings are compared.
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Slm Side Channel Lake is safe to swim in today is a call for the Illinois Environmental Protection Agency and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Slm Side Channel Lake
These are the measurements Illinois EPA publishes for Slm Side Channel Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 0.8 ft of visibility. Phosphorus 317 µg/L. Chlorophyll-a 95.6 µg/L. TSI 81.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 0.8ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 317µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 95.6µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 81 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Slm Side Channel Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Slm Side Channel Lake typically sits around 64°F at the surface in October. Summer average is about 86°F. Usually warmest in Jul (about 88°F) and coldest in Apr (about 63°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (63°F) to its warmest (88°F).
Typical surface water temperature by month, from 66 field readings (2011–2021) via the EPA Water Quality Portal. See the full Slm Side Channel Lake water temperature breakdown →
Stays via Stay22
Stays near Slm Side Channel Lake
Compare lakeside cabins, hotels, and vacation rentals near Slm Side Channel Lake in St. Clair County, Illinois — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Slm Side Channel Lake are listed below.
Top-rated places to stay near Slm Side Channel Lake
Prices for Oct 23–25, 4 adults. Change dates on the map below.
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Fishing Slm Side Channel Lake
Regulated Pollution Sources Nearby
3 EPA-permitted facilities operate within about 5 miles of Slm Side Channel Lake under Clean Water Act (NPDES) discharge permits. 2 facilities have a reported Clean Water Act violation in the past three years.
- Fayetteville StpFayetteville · 3.9 mi away · NPDES IL0020893Recent violation
- Mascoutah Stp, City OfMascoutah · 4.7 mi away · NPDES IL0025291Recent violation
- St. Libory Wtp, Village OfSt. Libory · 3.3 mi away · NPDES IL0053716
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.
Nearby Lakes in St. Clair County
Frequently asked questions about Slm Side Channel Lake
Where is Slm Side Channel Lake?
- Slm Side Channel Lake is a lake in St. Clair County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.
What is the water quality of Slm Side Channel Lake?
- Slm Side Channel Lake in St. Clair County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Water clarity: 0.8 ft visibility. Phosphorus: 317 µg/L. Chlorophyll-a (algae): 95.6 µg/L.
Is Slm Side Channel Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Slm Side Channel Lake?
- Slm Side Channel Lake typically sits around 64°F at the surface in October, from 66 EPA Water Quality Portal field readings (2011–2021). That is a typical value for the month, not a live reading.
Explore Slm Side Channel Lake across LakeQuality
Planning a trip around Gateway Arch?
Slm Side Channel Lake is about 27 miles from Gateway Arch National Park. Crowds there swing hard by season, so the month you pick changes both how busy the park is and what lodging costs.
Best time to visit Gateway Arch →More lakes in Illinois
Other Lakes in Illinois
Hypereutrophic Lakes in Illinois
Where this data comes from
22 measurements from 1 monitoring station, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- illinois epa
IL_EPA_WQX22 samples · 2021
Analytical methods
- MEASURED IN FIELD
- Phosphorus by Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Regulated discharger data from EPA ECHO (ICIS-NPDES)