Where void ratio has been estimated from the coefficient of uniformity (C<sub>U</sub>):
+
The void ratios above were estimated based on the coefficient of uniformity (C<sub>U</sub>)<ref>Vuković, Milan and Soro, Andjelko Determination of hydraulic conductivity of porous media from grain-size composition. Water Resources Publications, Littleton, Colo, 1992.</ref><ref>Odong, J. (2007). Evaluation of Empirical Formulae for Determination of Hydraulic Conductivity based on Grain-Size Analysis. Journal of American Science, 3(3). Retrieved from http://www.jofamericanscience.org/journals/am-sci/0303/10-0284-Odong-Evaluation-am.pdf</ref><ref>Zhang, S. (2017). Relationship between Particle Size Distribution and Porosity in Dump Leaching. the University of British Columbia. Retrieved from https://open.library.ubc.ca/collections/ubctheses/24/items/1.0357233</ref>: