I have to dig out my dwv that a tree has destroyed, it has caused sewage to come to the surface. The pipe is about 2.5m underground and my plumber has told me he needs a 1.5msq hole dig 2.5m deep. The only issue is that it's right in front of a large 1m high sandstone retaining wall. I'm worried about collapse. Dose anyone have any hints to make a support for it? I have a bunch of metal star posts and wood to make a brace but I don't know how or where to do this, I will also be digging out without machines to save on his quote. Thanks via /r/DIY http://bit.ly/2GZrggJ
