1. National Water Supply and Drainage Board, Telawala Road, Ratmalana 10390, Sri Lanka
2. Postgraduate Institute of Science, University of Peradeniya, Peradeniya, Kandy 20400, Sri Lanka
3. Instrument Centre, and Ecosphere Resilience Research Center, Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda 10250, Sri Lanka
4. Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), GeoZentrum Nordbayern, Schlossgarten 5, D-91054 Erlangen, Germany
5. Department of Geology, Faculty of Science, University of Peradeniya, Peradeniya, Kandy 20400, Sri Lanka