Drill, baby, drill! (But in the good way!)

Day one of drilling for the ground source heat pump. The plans call for two 286-foot deep holes, 6-inches in diameter, 20-feet apart on the north side of my house.  Given all the boulders sticking up out of my lawn, the driller anticipated hitting bedrock at a relatively shallow depth.  Instead we were surprised that we didn't hit bedrock until 43-feet down! So it was slow going drilling through the clay and boulders that were encountered above the bedrock.  Turns out that they like drilling through solid rock as they don't have to worry about stabilizing the bore hole with casings.  Once they hit the bedrock, they say that they can often bore 100-feet per hour.  With the midday start and the unexpected clay, they were only able to drill 140-feet today.

We asked them to stop at 6PM  so my neighbors could enjoy their dinner in peace.  The drillers are actually coming back on the weekend to finish the remaining drilling work! Hard workers!

When drilling through the clay, they circulated water from a small pit they excavated next to the drilling rig. I assume that was both to remove the cuttings from the bore hole and to cool the drill bit.

As you can see from the photos on the right they had to raise the rig in the vicinity of a nice old silver maple. They had to prune a number of small branches.  They actually tilted the truck while raising the drilling platform to avoid having to cut some branches.

I have to admit I was pretty nervous about the whole process but I'm feeling much better now that they have gotten started and that they didn't find anything completely ridiculous (yet). I am optimistic that they'll be able to complete the two bore holes tomorrow. And we'll be able to keep our schedule for next week!

After drilling, what's next? 

1. Insert the water pipes in the bore holes
2. Pump in the thermal grout to stabilize the pipes in the bore holes and make a good thermal connection to the ground.
3. Remove the refrigerant in the A/C system and remove the compressor/condensers
4. Trench a path the foundation
5. Bore holes in the foundation for the pipes
6. Drain my oil lines
7. Demolish/remove the old HVAC system and water heater 
8. Install the new water heater, holding tank and lots of piping
9. Install the electrical circuits for the GSHP and the water heater. 
10. Finally install the flow center and GSHP! 

We expect to be without A/C from the 11th to around the 19th. Hope the heat wave is over for the moment!! Usually that is not a big deal, but this summer has been so ridiculously hot! Hopefully that is not the "new normal" on Eaarth.