Long-Term Sequestration of Biosolids-Derived Carbon in Mine Reclamation

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Masters Thesis

Biosolids used in land application can improve carbon storage on-site, helping to mitigate climate change.  One of SYLVIS’s flagship reclamation projects, the Lehigh Sechelt Mine’s poplar plantation, was used as an example of successful biosolids reclamation in a scientific study.

Changes in land use are often tied to increases in carbon storage, such as in mine reclamation when recovering soil absorbs carbon from the air.  Some greenhouse gas offset systems award credit for certain projects that encourage increases in soil carbon storage. 

Since the late 1990s, SYLVIS has operated a progressive reclamation project at the Lehigh Sechelt Mine using regionally produced biosolids as a soil amendment to aid in several reclamation projects, including the growth of a hybrid poplar plantations.  This highly successful program has resulted in the reclamation of several hectares of formerly barren mine land, provided beneficial reuse opportunities for thousands of tonnes of biosolids, and is in the process of producing a salable wood crop.  The project is also working to store increasing amounts of carbon in the soil.

A graduate student at the University of Washington, Andrew Trlica, included the Lehigh Sechelt Mine reclamation areas in his study on the potential for mine reclamation with biosolids to aid in mitigating climate change.  Soil samples from the mine showed that areas reclaimed with biosolids stored more carbon than areas without biosolids. 

The project demonstrates the permanence of biosolids carbon sequestration.  Demonstrating carbon storage permanence is critical to obtaining greenhouse gas credits from eligible projects.  The use of biosolids at mines and other industrial settings has the potential to be a sustainable greenhouse gas offset strategy for these end users.  SYLVIS supports the research and technical personnel needed to keep at the cutting edge of knowledge at the nexus of biosolids management and climate change.