Sewage
The temperature of sewage tends to be slightly higher than in drinking water but it is more stable than the ambient temperature. The color of fresh sewage is slightly grey, whereas older sewage (also called "septic sewage") is dark grey or black. The odor of fresh sewage is "oily" and unpleasant. Older sewage has an unpleasant foul odor due to hydrogen sulfide gas and other decomposition by-products. Sewage can have high turbidity from suspended solids.