1. Department of Civil and Environmental Engineering, Stanford University, 450 Serra Mall, Stanford, California 94305, United States
2. Department of Civil, Environmental, & Infrastructure Engineering, George Mason University, 4400 University Drive, Fairfax, Virginia 22030, United States
3. Environmental Interventions Unit, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh