Water Stewardship Information Sources

ID 1580
Citation Barbour, S.L., M. J. Hendry, and S. Carey (2016) High-resolution profiling of the stable isotopes of water in unsaturated coal waste rock, Journal of Hydrology, Vol. 534, pp616-629. doi:10.1016/j.jhydrol.2016.01.053
Organization University of Saskatchewan/McMaster University
URL http://www.sciencedirect.com/science/article/pii/S0022169416000718
Abstract/Description or Keywords Characterization of the rate of water migration through unsaturated mine waste rock dumps is an essential element in assessing the chemical loading from these landforms; yet our understanding of how water moves into, through and out of waste rock is incomplete. To further understand the rates and magnitude of percolation through waste rock, deep high-resolution (every 0.1–4.5 m) depth profiles of the stable isotopes of water (_2H and _18O) at two coal waste rock dumps and a natural alluvial deposit down-gradient of one of the dumps were collected in the Elk Valley, British Columbia, Canada. The profiles were generated using vapor equilibrium techniques applied to continuous core samples collected using dry sonic drilling methods. Elevated core temperatures (up to 80 °C) were measured during sonic coring. The isotopic values of pore waters measured in the core samples were corrected for water loss to the atmosphere attributed to the elevated core temperatures. The average isotopic composition of the core samples were compared to water collected from rock drains discharging from the base of the dumps. The results indicate that high-resolution profiles of _2H and _18O can be measured to depths of 86 m in coal waste rock dumps and, based on the seasonal cycles in the isotopic composition of recharging water, can be used to characterize the migration of recharge water within these dumps. These profiles also suggest that recharge into these dumps occurs from both rain as well as snow melt and may be as high as 400–600 mm/yr (60–75% of annual precipitation). Combined with the relatively low volumetric water contents of these dumps (5–10%) the rates of water migration through the dumps are tens of meters each year.
Information Type Article
Regional Watershed Elk River
Sub-watershed if known West Line Creek
Aquifer #
Comments
Project status
Contact Name S. Lee Barbour
Contact Email [email protected]