University of Alaska, Institute of Water Resources
Abstract
Aerobically digested sludge from the Fairbanks sewage treatment
plant was worked into the soil on several plots at the University of
Alaska in the summer of 1978. Some of the sludge had been air dried for
up to six months prior to application while some was taken directly from
the thickener. Applications varied from 12 to 100 tons of solids/acre.
For sludge applied in July and August, the fecal coliform count
decayed by several orders of magnitude by the middle of September..
There was no significant movement of fecal coliform bacteria either
vertically or laterally. Lime was used to raise the pH of one plot to
12, completely killing the fecal coliform bacteria within several days.
The nutrient distribution demonstrated the potential for enriching soils
by sludge addition.
The main purpose of the study was to investigate the feasibility of
this concept for remote military sites. Air drying followed by land
application may represent a viable means of sludge disposal.This study was performed for the U.S. Army Cold Regions Research
and Engineering Laboratory (USA CRREL) and was funded under DA Project 4A762720A896, Environmental Quality for Construction and Operation of Military Facilities, Task 02, Pollution Abatement Systems