The purpose of this study was to evaluate the long-term environmental
effects of applying alum sludge to land. Investigations at the origina
l field site included soil analysis, soil water monitoring, groundwate
r monitoring, and analysis of tissues from pine needles. No long-term
(30 months) effects were observed, and the authors conclude that alum
coagulant sludges can be applied to forest lands at loading rates of a
t least 1.5 to 2.5 percent by dry weight without adverse effect.