Bull Frog Lake
Cook County, IllinoisView mapDirections
No nutrient or algae sampling on record from Illinois EPA for this lake.
- Impaired · Algal growth
- Limited data
Bull Frog Lake in Cook County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported.
Bull Frog Lake is a lake in Cook County, Illinois.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2022-03-21. Methodology: how these readings are compared.
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Bull Frog Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, noxious aquatic plants, nutrients (phosphorus, nitrogen), turbidity. Check local advisories before you swim.
Whether Bull Frog 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 Bull Frog Lake
These are the measurements Illinois EPA publishes for Bull Frog Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data.
Ask about Bull Frog Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Bull Frog Lake typically sits around 60°F at the surface in October. Summer average is about 76°F. Usually warmest in Aug (about 79°F) and coldest in Oct (about 60°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (60°F) to its warmest (79°F).
Typical surface water temperature by month, from 45 field readings (2010–2022) via the EPA Water Quality Portal. See the full Bull Frog Lake water temperature breakdown →
Stays via Stay22
Stays near Bull Frog Lake
Compare lakeside cabins, hotels, and vacation rentals near Bull Frog Lake in Cook 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.
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Fishing Bull Frog Lake
Reservoir Info (USACE NID)
Bull Frog Lake is a man-made reservoir impounded by the Bullfrog Lake Dam (completed 1958), built primarily for recreation on the TRIB DES PLAINES RIVER; earth-type dam, 17 ft tall and 700 ft long.
- Normal storage
- 77 ac-ft
- Max storage
- 144 ac-ft
- Hazard class
- Significant
- Owner
- FOREST PRESERVE DISTRICT OF COOK COUNTY
Source: USACE National Inventory of Dams, NID ID IL00869 · Operator website
EPA Impairment Status
Bull Frog Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Other.
Source: EPA ATTAINS assessment unit IL_RHZF · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Bull Frog Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Rowell Chemical CorporationWillow Springs · 0.7 mi away · NPDES IL0066613Recent violation
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 Cook County
Frequently asked questions about Bull Frog Lake
Where is Bull Frog Lake?
- Bull Frog Lake is a lake in Cook County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.
What is the water quality of Bull Frog Lake?
- Bull Frog Lake in Cook County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported.
Is Bull Frog Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Bull Frog Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, noxious aquatic plants, nutrients (phosphorus, nitrogen), turbidity. Check local advisories before you swim.
What is the water temperature of Bull Frog Lake?
- Bull Frog Lake typically sits around 60°F at the surface in October, from 45 EPA Water Quality Portal field readings (2010–2022). That is a typical value for the month, not a live reading.
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Where this data comes from
1 measurement from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- USGS Illinois Water Science Center
USGS-IL1 sample · 2022
Analytical methods
- Secchi disk method
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
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)