Control Of Fugitive Emissions From Tailings Ponds

Teck Coal has developed a strategy for fugitive dust control from fine tailing ponds that uses vegetation, tackifiers and strategic fencing. Here, Teck shares program learnings and methods with COSIA, which may be relevant to future joint industry projects. They note that in the early 1980’s, dust control did not receive much attention, even following major dusting events. Dust control now takes a high priority, with the overlying principle that dusting is not acceptable. The current approach is a proactive one that focuses on keeping the dust on the ground and not allowing it to become suspended – once the dust has become suspended it is all but impossible to knock it down and control it. Along with a Dust Control Procedures document outlining details about dust control tools used, a Dust Management Plan is provided in the form of a map of the Lagoon with dust control tools/features labelled.

Dusting can occur at any time of the year when wind speeds exceed 25 kph (hourly average with gusts occurring). Each season brings individual problems and difficulties – what works in one season does not necessarily work in another. For example, it is impossible to run the irrigation system in the winter. To combat this, new techniques and ideas are continually being investigated that give better control in each of the four seasons. Tools for dust control: (1) irrigation – used when possible (not frozen); (2) tackifying – this consists of spraying a mixture of water and a green polymer tackyfying agent onto the surface of the Lagoon in order to stick the fine particles together so that they cannot be picked up by the wind, and is the main method of dust control during the periods when the irrigation system cannot be operated (due to freezing); (3) seeding – works well in areas that will not soon be disturbed. Fall rye needs 3 weeks of irrigation before it controls dust, and then it works well. Conifer planting is also occurring to increase wind protection; (4) wind fences – not super effective, labor intensive, relatively ineffective in knocking dust down once it has become wind born. Localized placement of wind-fences is being considered on the outside western end of the Lagoon upwind of residential areas.