I had a contractor install and underground sump pump discharge pipe in my yard. The pump was overflowing at the air gap. The attached image is the contractors solution. My concern is freezing. The contractor states that if it freezes the water should discharge out of the top vent pipe. I think this will not happen. Has anyone ever saw a discharge with a vent like that? I think they buried too small a diameter pipe and dont want to fix it properly.
