CHELAN — The cleanest lake in America is Lake Chelan, which jumped to #1 after placing second on the list last year by vacation rental property website, Lake.com, who commissioned tests in conjunction with the National Water Quality Monitoring Council.
The new ranking is based on a rolling five-year sample of contaminates and water clarity factors. The study analyzed all the available chemical data from the NWQMC for 100 of America’s largest lakes, sampled from January 1st, 2021, until July 30th, 2026. The study evaluated eight of the most commonly measured characteristics that can indicate a lake’s cleanliness level:
- Dissolved oxygen
- Ammonia
- Lead
- Phosphorus
- Sulfate
- Total dissolved solids (TDS)
- Turbidity
- pH levels
A total of 67 lakes reported at least three of these pollution factors and therefore qualified for the study. The findings were put into an index to produce a pollution score out of 10 to determine the safest and most dangerous lakes based on hygiene, pollution and more.
Lake Chelan–a summer recreation mecca in central Washington–is the only lake in the data to score a perfect 0 — the next cleanest, Lake Superior, registers 0.28. The fifth cleanest lake, Franklin D. Roosevelt Lake in central Washington, registered 0.72.
Lake Chelan has turbidity of just 2.00 NTU, meaning it’s extremely clear, and one of the lowest TDS levels at 30.25 mg/L. Lake Chelan also experiences low sulfate levels of 3.65 mg/L.
However, Lake Superior, which was the cleanest lake in last year’s report, ranks a close second with the lowest turbidity of any lake (0.54 NTU), low TDS levels (74 mg/L), and high oxygen levels (10.58 mg/L).
For the methodology on the study and the complete Top 10 ranking, the full report is linked here.
Campbell’s Resort in Chelan, at the southeast shore of the 25-mile long Lake Chelan, posted this message on their Facebook Page about the #1 ranking, “Lake Chelan has been named the cleanest lake in America, taking the top spot in a new ranking by Lake.com. A special thank you to the Lake Chelan Research Institute for their ongoing work to study, protect and preserve the lake we all love, helping keep its waters crystal clear for generations to come.”