FOG Freiberg Online Geology FOG is an electronic journal registered under ISSN 1434-7512 2011, VOL 28 Samer Bachmaf and Broder J. Merkel Department of Hydrogeology, Technische Universität Bergakademie Freiberg, Gustav-Zeuner Str.12, 09599 Freiberg, Germany. E-Mail: samerbachmaf@yahoo.de ; merkel@geo.tu-freiberg.de Estimating Water Chemistry Parameters from Experimental Data Using PEST with PHREEQC 18 pages, 2 figure, 0 tables, 21 references