Is Lac Courte Oreilles Lake Polluted?
Yes — Lac Courte Oreilles Lake in Sawyer County, Wisconsin is on the EPA's Clean Water Act 303(d) impaired-waters list (2024 assessment cycle). It is cited for Cause unknown. No cleanup plan (TMDL) has been completed yet. "Impaired" is a legal designation, separate from the lake's EPA condition class water-quality readings: it means at least one designated use (such as swimming, aquatic life, or fish consumption) does not meet state standards for the listed pollutant.
EPA 303(d) Listing
| On 303(d) impaired list | Yes |
| Cleanup plan (TMDL) | Not yet written |
| Assessment cycle | 2024 |
| EPA IR category | 5 |
| Uses not supported | Aquatic life |
| EPA names this lake in the listing | Yes |
| Location | Sawyer County, Wisconsin |
Pollutants Cited
- Cause unknown — listed by EPA as exceeding water-quality standards for at least one designated use.
Specific parameters in the EPA record: Cause Unknown.
What this means for using Lac Courte Oreilles Lake
Review the EPA assessment and any state advisories before relying on Lac Courte Oreilles Lake for swimming, fishing, or other uses. An impairment listing does not mean the lake is closed — most impaired lakes remain open for boating and swimming. It means a specific pollutant exceeds a standard for a specific use. Lac Courte Oreilles Lake measures algae (chlorophyll-a) at 1.7 µg/L and phosphorus at 15 µg/L. See the full breakdown on the lake report. The official EPA assessment is available in the ATTAINS waterbody report.
Stays via Stay22
Where to stay near Lac Courte Oreilles Lake
Compare cabins, hotels, and vacation rentals near Lac Courte Oreilles Lake in Sawyer County, Wisconsin. Live availability and prices for your nights. Switch the map to Satellite to see how close each stay is to the water.
Top-rated places to stay near Lac Courte Oreilles Lake
Prices for Nov 6–8, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip to Lac Courte Oreilles Lake?
Get lake water-quality updates plus the best cabin & lodging deals near Lac Courte Oreilles Lake — straight to your inbox. No spam, unsubscribe anytime.
Watch Lac Courte Oreilles Lake water quality
Get an email when the clarity or algae readings change. Unsubscribe anytime.