1
BRound Lake
Lake County, Wisconsin · 3.1 mi from Long Lake
- +Two grade letters higher (D → B)
- ++4 ft water clarity
- +Lower phosphorus (19.5 vs 35 µg/L)
Cleaner Lakes Than Long Lake
2 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Long Lake carries a Grade D (Poor) water quality score. Within 30 miles, 2 lakes hold a higher grade. Round Lake (Lake County, Grade B, 3.1 mi away) is the closest meaningful upgrade.
2
BLily Lake
McHenry County, Wisconsin · 5 mi from Long Lake
- +Two grade letters higher (D → B)
- +Lower phosphorus (16 vs 35 µg/L)
How this list is built
Every lake on LakeQuality has a calculated grade from EPA Water Quality Portal samples — secchi depth, total phosphorus, and chlorophyll-a measured against Metropolitan Council thresholds. To suggest cleaner alternatives, we filter lakes within 30 miles to those with a strictly higher numeric score, then rank by grade improvement with a small proximity tiebreak. Cross-state and limited-data lakes are excluded so the list stays locally relevant.