Long-term effects of sludge application to land

The purpose of this study was to evaluate the long-term environmental effects of applying alum sludge to land. Investigations at the original field site included soil analysis, soil water monitoring, groundwater 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 at least 1.5 to 2.5% by dry weight without adverse effect.