Efficacy of Pond Ash as a Cover Material in Single and Dual Capillary Barriers C.S.S.U. Srikanth, B.J. Ramaiah, A. Murali Krishna and Sai K. Vanapalli E3S Web of Conf., 382 (2023) 21004 Published online: 24 April 2023 DOI: 10.1051/e3sconf/202338221004