I am having a new EPDM roof installed on a 220 sq flat roof. It is not quite done and I am paying 10k for this roof and an Aztek railing. I noticed yesterday that under the New EPDM there are several areas that have debris under the EPDM on top of the ISO Board. They didn't clean it off well enough I assume. The Roofer assures me it is not an issue and that there is No fix for this. I have little exp with roofs. I'm not paying this amount of money for crap work, but not sure what to do. What would you all do??