NUTRIENT AND ALGAL CRITERIA FOR TROPHIC CLASSIFICATION OF COLVILLE RESERVATION LAKES.

The table below gives the nutrient and algal criteria for classifying lakes on the basis of lake productivity. The values range from those of low productivity Lakes (Oligotrophic) to high productivity lakes (Eutrophic) with values in between indicating more or less average productivity lakes (Mesotrophic).
Productivity Criteria Oligotrophic Mesotrophic Eutrophic
Total N micro g/L at spring overturn <100 100-500500-1000
Total P, micro g/L at spring overturn 0-2 2-7>7
Chlorophyll a, micro g/L growing season mean 0-2 2-7>7
Secchi disc (m), growing season mean 6 3-6<3
Hypolimnetic oxygen depletion rate mgOxygen/square m/day <250 >500