The day of the big tank, the big hole, the big tank in the big hole and then both disappeared.
Gary from ATU Wastewater rocked up nice and early, with his 8t excavator and driver in tow – when I got on site they’d already ripped out a tree that was in the way, marked out the hole and had just about started digging.
I’d been worried about hitting rock on this dig – the soil test guys said they’d hit rock at ~1.6m where the house is going to be, and I was hoping we’d get a bit deeper down in this corner. The hole needed to be 3x3m and 2.4 deep to hold this monster:
The excavator got about 1m down with the bucket alone. He then had to switch to his ripping tine to break up the not-quite-rock-very-hard-sand stuff below that, which got us down to about 1.8m, then the ripper couldn’t get any further and out came the rock breaker.
The last metre took the better part of two hours of very slow rock-breaking and scooping, but eventually we had a deep enough hole. Dropped some dirt back into it, which Gary went down and levelled:
The monster HIAB finally got to do its thing (after sitting around all morning waiting for us to break rocks), and in 10 minutes the tank was in. Some more dirt ballet from the excavator (and 90 minutes filling the whole thing with water) and I have a lovely new septic tank.
And a big pile of dirt and rocks to play with.
This thing doesn’t actually *work* yet – I have to run power down to it first – but it was definitely the right call putting it in early rather than try and squeeze some pretty big machinery past the house later. Getting it this far in the ground makes the plumbing a bit easier, too – roughly 1.3m of fall from the floor level of the house to the inlet pipe of the ATU, which is 600mm under the ground.