I am a stonemason and am considering building a small, indoor pond/waterfall to use for my dog's water bowl. I live in a warehouse studio with concrete floors and brick walls so i was thinking about using mortar to build the waterfall in a corner. It would be made of granite, with EPDM lining. Basically my question is, if the water is running over mortar and collecting in an EPDM dish, would it be safe for my dog to drink out of? Thanks, and if anyone has any insight on this I would be greatly appreciative, as I am anxious to start this project.