I had a septic guy come out a while ago because one my lateral lines in my leach field was wet. He determined that line was taking the majority of the water and build a little blockage out of some type of cement so that my other line would take most of the water. He told me to let things dry out then knock out the cement, it all worked wonderfully. He was going to put a shut off valve in but determined that the distribution box was in really good shape and didn't want to go messing with it. The little mound of cement worked great and I would like to do it again but I'm curious as to what he used. He rolled it into shape in his hands and set it in and it dried very quickly. I tried calling him but he isn't answering. Does anybody know what I could use? I don't want to go messing around with cement in my distribution box for fear of getting stuff down my lines. Thanks.