There is a slow water leak into our house from around the sewer pipe where it connects the interior pipes through the concrete outer wall to the main sewer line. The water appears to be clear, not raw sewage. We have a plumber coming tomorrow (we hope they show!) to diagnose, but we fear there is a crack in the pipe. Is there a way to fix a leaky sewer pipe from inside the pipe, so we don't have to dig up our yard?