Twice in the past three years I have discovered waste matter on my lawn around the sewer vent pipe which was filled with water. On both occasions, plunging overcame the problem. During the past six months I have had the sewer lateral replaced and my sewer line was examined by video camera and declared clear. Since the waste matter included grease and food products, supposedly from my garbage disposal, besides curtailing my use of the disposal, are there any chemical products I might use to keep the pipe clear?
Thanks in advance.