British Columbia Mine Reclamation Symposium

Sediment yield from waste dumps and the potential ability of dump slide material to filter suspended sediment Bittman, Kim

Abstract

This paper presents a case history of the Mesa 1660 m dump failure (slide) at Quintette Coal Limited. The potential ability of dump slide material to filter suspended sediment from influent water is discussed and questions are raised regarding the amount of sediment generated by waste dumps. This paper presents data and theoretical arguments supporting the following claims: 1. That dump slide material filters suspended sediment - supported by: - Experience at an east Kootenay mine showing a dramatic decrease in sediment loads subsequent to a failure. - Experience at Quintette Coal Limited indicating that solids concentrations below the Mesa dump slide are less than upstream concentrations in 49% of samples taken and of the same concentration in 30%. Slight increases downstream are seen in 21% of the data set. - Dye observations indicating that an approximate retention time in the slide mass is 69 hours. 2. That waste dumps are not likely to produce high sediment loads - supported by: - During the dumping process, fines remain in the upper 10% of a waste dump and in this zone, based on specific tests in the Mesa north area, comprise clay particles (0.002 mm) at 2% and fine sand or silt (0.075 mm) at 9% of the samples taken. - Natural segregation of waste dumps will preclude downward migration of fines from the upper portion to lower regions of a waste dump. - An extensive history of waste dump drainage at QCL, including a five year sampling record indicating that negligible suspended sediment loads are generated.

Item Citations and Data

Rights

Attribution-NonCommercial-NoDerivatives 4.0 International