3. Clean Zone
Normal clean water organisms
(trout, perch, bass,
mayfly, stonefly)
8 ppm
Decomposition
Zone
Trash fish
(carp, gar,
leeches)
Septic Zone
Fish absent, fungi,
sludge worms,
bacteria
(anaerobic )
Recovery Zone
Trash fish
(carp, gar,
leeches)
Dissolved oxygen
Oxygen sag
Biological oxygen
demand
2 ppm
Direction of flow
Point of waste or
heat discharge
Time or distance downstream
Clean Zone
Normal clean water organisms
( trout, perch, bass,
mayfly, stonefly)
8 ppm
