1
CGrass Lake
Anoka County, Minnesota · 7.2 mi from Foster Lake
- +Two grade letters higher (F → C)
- ++2.3 ft water clarity
- +Lower phosphorus (23 vs 197 µg/L)
Cleaner Lakes Than Foster Lake
1 higher-graded lake within 30 miles, ranked by grade improvement and proximity.
Foster Lake carries a Grade F (Very Poor) water quality score. Within 30 miles, 1 lake holds a higher grade. Grass Lake (Anoka County, Grade C, 7.2 mi away) is the closest meaningful upgrade.
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.