Hello everyone. When permeability of drainage layers is mentioned, permeability values of around 1000ft/day or higher are commonly mentioned as a minimum for this type of layer. Does anybody know if there is a standard permeability test from where this value is supposed to be obtained? Is this from a typical laboratory permeability test (if so, which standard?) Where did this minimum permeability value come from? On another topic, does anybody have information (or links to information) about constructability issues in Untreated Permeable Bases? Thanks.