I have to drains that run through my basement floor. One is the large main drain and one is a secondary drain that drains the kitchen sink then the washer and utility sink in the basement. At the base of this secondary drain where it goes through the basement floor to the ground I get a little mud built up and some moisture. This only happens every few weeks. I try to duplicate the problem by running water through that drain for several minutes but get nothing? The basement is bone dry everywhere and the sump has never run? Is this ground water? Could it be a broken drain tile? Should I snake it?