Plastic contamination is commonly reported in urban and rural soils, as well as in fresh and ocean waters. Canada’s government has attempted to limit the contamination of single-use plastic by banning the manufacturing and selling of specific types of plastic. In British Columbia, current regulations governing commercial composting state that when compost has less than 1% of its dry weight representing foreign materials (including plastic), it can be sold and used in soils. However, due to the low density of plastic and its potential to break down into microparticles, this amount may be enough to become toxic when used in agricultural soils. This paper studies contamination of plastic in garden soils and summarizes how this can affect the environment with a preliminary examination of a garden soil sample. The examination showed that the garden soil sample contained mainly low-density polyethylene, polyethylene and polypropylene plastics (identified through ATR-FTIR) in oxidized and unoxidized forms that can come from commercial composting and hypothesizes that this plastic could break down into microplastic particles. In order to limit the amount of plastic contamination in agricultural soils, it is necessary to modify current compost regulations in order to treat plastic differently than other foreign materials (glass, metal, wood).

This study compared a water-based and a solvent-based method for removing ash (washing) from coal: jigging coal in water using the Roben Jig and the float/sink method using conventional organic liquids (naphtha, perchloroethylene, methylene bromide), respectively. Clean coal curves from the two processes were compared for six coal types from British Columbia, Canada. The clean coal curve for the Roben Jig deviated from that of the organic liquids when the near-density material content was high. Also, particles were misplaced within the jigging column; however, a simple “rejig” process was capable of further cleaning the coal. The Roben Jig was used to create a clean coal sample of at least 400 kg by washing coal in batches. The clean coal curves for the jig were similar. Minor differences could be attributed to the occurrence of misplaced particles. Although the Roben Jig does not provide perfect separation of coal based on density for use in wash plant design studies, previous work has established that it is capable of creating representative clean coal composites without the use of organic liquids.

Although dominant western narratives often imply otherwise, mining is not just a colonial idea or activity. First Nations have been mining and quarrying rocks and minerals for thousands of years, using the extracted materials for cultural, spiritual, medicinal, and practical purposes. The literature documenting the use of rocks and minerals by First Nations peoples has been produced by archaeologists, and very little is known about these activities within the context of mining engineering and geoscience. By documenting the knowledge, resource management and science behind First Nations use of rocks, minerals and mining, we can contribute to the decolonization of the mining sector, while also helping to drive much needed innovation. The mining industry is now evolving to focus more attention on smaller and lower grade deposits, reprocessing of waste, sourcing independent supplies of critical minerals, and Indigenous reconciliation. Continued advances in these areas, inspired from the lessons of First Nations mining, are needed to transition the industry on a path to social and environmental sustainability. Working with Indigenous peoples to incorporate Indigenous ways of knowing into mine design and reclamation could be the key to overcoming the challenges ahead.