Riparian Reclamation

In many cases, establishment of aquatic ecosystems in tailings ponds and pit lakes would occur naturally without intervention, but over a much longer period. Work at Teck’s Highland Valley Copper mine has explored a number of projects and methods to speed and enhance development of tailings ponds and pit lakes into functional aquatic ecosystems, and have also explored their use in aquaculture. These projects describe best practices and learnings from these projects, which could be valuable to share with oil sands and could form a future joint industry project.

For tailings pond conversion to aquatic habitat plus bioreactor: (1) fertilize with macro/micro nutrients (need for N and possibly P may be ongoing); (2) introduce: (a) aquatic macrophytes (weed sandwiches, seed heads, sediment transfer); (b) aquatic invertebrates (in hay flakes, live trapped, moved with vegetation or sediment) and (c) riparian vegetation (willow staking, sedge plugs, cattail seed heads, leave mud flats); (3) (a) introduce fish (> 4 m and after plants and invertebrates are well established); (b) enhance shoreline with nesting sites to develop waterfowl habitat (in tailings ponds < 4 m). Pit lakes are similar, except need more initial testing and inputs and carbon added, and need for external input of vitamins and nutrients may be ongoing longer. Floating habitat can be created using bio-islands; permeable floors support soil layer in which riparian shrubs/emergents grow, roots grow into water below, and they provide nutrients and growth surface. Developing aquaculture sites after reclamation could help companies continue to connect with/support community after mine closure and generate revenue. However, caution must be used in terms of metals uptake, site hydrology and other environmental issues. In areas where metal uptake is high, sites could be used for sports fishing or ornamental fish farming rather than food fish.