We are moving into periodic and repeat applications, spring versus fall applications, and more ground water and tree growth studies. For example, oceans are closed to biosolids. Landfilling them can have negative environmental effects and is becoming very expensive.
Incineration also can have environmental problems.
Forest land is an attractive alternative to these. Since forests are one step removed from the human food chain, they are a safe place to use biosolids, which have fertilizer value and organic matter, both of which will improve tree growth. When biosolids are applied properly, there are no adverse effects on the local environment, including the groundwater. There are also no adverse effects on wood quality. In addition, application scheduling of biosolids is often not as complex as it is in other agricultural uses.