Before the actual foundation slab is installed, the plumbing lines for the house had to be laid and tested. As soon as this had been done, the septic installers were back, digging the hole for the tank and laying the septic field. The digging is one of the hardest bits of work that has to be done as it is basically entirely bedrock. Originally the tank had been planned to be on the east side of the house, but in discussions between our builder and the septic installer, it was felt that being to the north, where test trenches had showed that there was a bit more topsoil, might mean less need to dig through bedrock. In practice, I don’t think it’s made as big a difference as anticipated, and the downside is that the septic field has to extend further north down the slope where our forest garden area starts. Unfortunately I’m not generally around when the work is being done, and we’ve already lost one of the trees that I planted four years ago, and I’m worried we will lose some more.