Services: Water borehole

It made sense to have the borehole drilled before starting work on building the house, not least because a lot of trades would need copious amounts of water. To comply with health regulations, the borehole needed to be sited over 50 metres away from our septic tank. This was a bit of a squeeze on our site and unfortunately one of our nicest flowerbeds bit the dust.

The drilling rig arrived on a trailer accompanied by a giant compressor to power it. The business end of the drill was a tungsten carbide drill bit, not much bigger than a football but so heavy that one person could hardly lift it.

The drilling rig was set up in the corner of the garden (goodbye flowers) and drilling commenced. The plan was to drill to a depth of around 40 metres which would hopefully hit a decent supply of water. No drilling company offers any guarantee though; the nearest farm to us had to drill 80 metres deep and even then ended up with iron-heavy water that looked like a thick orange sludge.
We weren't sure what we were going to find and how much extra it was going to cost us if they had to drill beyond 40 metres.





Drilling the borehole...

Each drill shaft was a metre and a half in length and they were screwed together as the drill descended.





To protect the shallowest part of the borehole from contamination, a plastic pipe was installed for the first 6-7 metres and backfilled with concrete. Once the concrete had set, drilling restarted.







Luckily we struck water within a few hours. The drillers tested the flow rate and it looked very promising. For most domestic properties they look for a flow rate of 1 gallon per minute - ours was already flowing at 10 gallons per minute and was also looking remarkably clear.

Having hit such a large vein of water at 31.5 metres the drillers thought it pointless to drill any deeper just for the sake of it. There was also the risk of hitting a seam of iron or manganese which is very common in our area.

A lot of crushed slate was produced from the borehole leaving us with lots of clearing up to do.


 


Once drilling was completed the borehole was lined with perforated pipes.

A concrete cover was cemented into the ground to protect the borehole and to house some of the pump equipment...It almost looked like a gravestone in rememberance of the desolation to our poor flowerbed.





Though it's good that we found so much water, there's a lot more to do before we can just turn on the tap for a nice drink. Next we'll be installing the pump and getting the water tested to find out what type of filtration we need.