Lake.com Reveals America’s Cleanest and Dirtiest Lakes for 2026 on World Lake Day

Washington’s Lake Chelan takes the top spot for cleanliness, while Utah’s Great Salt Lake ranks as the dirtiest

NEW YORK, NY, UNITED STATES, August 27, 2026 /EINPresswire.com/ -- Lake.com, the travel platform dedicated exclusively to stays and experiences by the water, today released its 2026 ranking of the cleanest and dirtiest lakes in the United States, revealing significant differences in water quality among some of the country’s largest and most popular lakes.

Key Highlights
Cleanest lake: Lake Chelan in Washington ranks as America’s cleanest lake.
Dirtiest lake: The Great Salt Lake in Utah ranks as the nation’s dirtiest.
Lakes analyzed: 100 of the largest lakes in the U.S.
Lakes ranked: 67 with up-to-date chemical composition data.

The study analyzed water-quality data from the National Water Quality Monitoring Council (NWQMC) for 100 of the largest lakes in the U.S. Researchers evaluated eight indicators used to assess lake cleanliness: dissolved oxygen, ammonia, lead, phosphorus, sulfate, total dissolved solids (TDS), turbidity and pH. Using the most recent 12-month median for each indicator, drawn from data reported between Jan. 1, 2021 and July 30, 2026, 67 lakes had sufficient data to be included in the ranking.

The findings come as communities around the world recognize World Lake Day on Aug. 27, an observance established by the United Nations to celebrate the importance of lakes and raise awareness of the need to preserve and sustainably manage lake ecosystems.

America’s Top 3 Cleanest Lakes: Lake Chelan Takes the Top Spot
The lakes with the lowest pollution scores shared several characteristics: clear water, relatively low concentrations of dissolved minerals and pollutants, and healthy dissolved oxygen levels. Among the 10 cleanest lakes, available measurements showed turbidity below 5.26 NTU, TDS below 200 mg/L and dissolved oxygen levels above 8 mg/L.

No. 1 — Lake Chelan (Washington) earned the cleanest overall score in the 2026 analysis, with turbidity of just 2.00 NTU and one of the lowest concentrations of total dissolved solids in the study at 30.25 mg/L. Together, these measurements are consistent with exceptionally clear, clean water.
No. 2 — Lake Superior (Michigan, Minnesota and Washington) recorded the lowest turbidity in this year’s analysis at 0.54 NTU, along with low dissolved solids and high dissolved oxygen levels.
No. 3 — Lake Martin (Alabama) rounds out the top three cleanest lakes in this year’s analysis, with low turbidity of 1.28 NTU, healthy dissolved oxygen levels of 8.15 mg/L and a pH close to neutral.

“Lakes have always been places where people go to swim, boat, fish, explore and spend meaningful time together, and World Lake Day gives us an opportunity to celebrate them while also paying attention to their health,” said David Ciccarelli, founder and CEO of Lake.com. “What’s encouraging is that many of the largest lakes in the U.S. are, on the whole, clean and enjoyable places to visit. The differences we see from lake to lake also reinforce the importance of continued monitoring and care for these incredible natural resources.”

America’s Top 3 Dirtiest Lakes: Great Salt Lake Anchors the Bottom
At the other end of the ranking, lakes with the highest pollution scores showed a wider mix of water-quality concerns, including greater pH variation and elevated sulfate, ammonia, lead and phosphorus levels. Available measurements among these lakes showed turbidity as high as 65.55 NTU, TDS above 180 mg/L and dissolved oxygen as low as 3.65 mg/L.

No. 1 — The Great Salt Lake (Utah) received the highest pollution score in the 2026 analysis, driven primarily by a TDS concentration of 134,500 mg/L, far exceeding any other lake included in the study. That finding comes with an important caveat: unlike most of the lakes analyzed, Great Salt Lake is a terminal saline lake from which water leaves primarily through evaporation, leaving salts and other minerals behind. As a result, its unusually naturally high mineral content contributes substantially to its position in the ranking.

No. 2 — Lake McConaughy (Nebraska) and No. 3 — Lake Winnebago (Wisconsin) follow the Great Salt Lake with the second- and third-highest overall pollution scores.

Other notable findings:
Devils Lake (North Dakota) recorded the highest sulfate concentration in the study at 639 mg/L.
Lake Moultrie (South Carolina), while outside the 10 lakes with the highest overall pollution scores, recorded the highest lead concentration in the analysis at 17.2 µg/L.

The report conveys this information with impartiality, avoiding any judgment, while offering a factual foundation for communities and agencies to address these concerns constructively.

“Where a lake falls in a national ranking is only part of the story,” Ciccarelli said. “Every lake is different, and water conditions can vary considerably from one location and one day to another. For travelers, the most important thing is to pay attention to local water-quality information and posted guidance while doing their part to leave these places as beautiful as they found them.”

To read the full report, visit https://www.lake.com/company/reports/cleanest-and-dirtiest-lakes-in-america/


About Lake.com
Lake.com was founded by a husband‑and‑wife team with a shared passion for helping families experience the beauty of God’s creation. Today, the platform features more than 75,000 vacation homes across North America and Europe, with a focus on transparent pricing, no guest fees, and family- and pet-friendly stays. By combining trusted destination guidance with a purpose-built marketplace, Lake.com is building the next generation of travel for those drawn to the water. For more information, visit www.lake.com.

Sarah Stahl
Lake.com
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