1
AUnion Lake
Polk County, Minnesota · 2.4 mi from Sarah Lake
- +Higher grade (B → A)
- ++6.6 ft water clarity
- +Lower phosphorus (14 vs 29.5 µg/L)
Cleaner Lakes Than Sarah Lake
2 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Sarah Lake carries a Grade B (Good) water quality score. Within 30 miles, 2 lakes hold a higher grade. Union Lake (Polk County, Grade A, 2.4 mi away) is the closest meaningful upgrade.
2
BCable Lake
Polk County, Minnesota · 7.6 mi from Sarah Lake
- +Higher overall water quality score
- ++2.3 ft water clarity
- +Lower phosphorus (20 vs 29.5 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.