I have a newly installed 24" Ribbed PVC pipe that is not yet in service. It has about 15' of cover. In the pipe zone it has clean washed sand to 1 ft above the crown. The backfill above the pipe zone is a sandy clay compacted pretty tight, say 95% proctor, all the way up. The pipe was air tested but when a 5% mandrel was tried, it would not enter the pipe. Video inspection shows a consistent egging along the entire length of the pipeline. Short of digging it up and relaying it, are there other options to 'repair' the egging and get it back to near round?