Hello, I'm new to this forum and have a few septic system questions. The septic tank at my parents house has been working just fine until a few years ago. First of all it hasn't been pumped in probably over 20 years (I know...). The tank appears to be a single tank with a divider and an overflow tube from one side to the other. Several years ago they replaced a length of lateral line and it seemed to be working until just recently. In January of this year we had it pumped and the guy said the second side was full of sludge so he pumped that also. We started having some more problems and had another guy come out and pump it again and install a new lateral line. I looked in the tank recently and saw that the second side was full of sludge. I took the first guys word that he fully pumped it out but didn't verify how much he left in it and I also don't know to what extent the second guy pumped. My questions is will this sludge compromise the new lateral line? Do we need to have it pumped again to get ride of all of the sludge. Any suggestions?