Given the recent storms Ciara and Dennis it seems appropriate somehow to be writing about water this weekend. We took the decision last year that we would like to be off-grid for water see: https://suewardell.com/2019/11/07/boreholes-divining-and-water/
In January we finally commenced the drilling for our borehole. This followed on from the positive results of the Geological survey that was done in December
There is considerable risk in drilling for a borehole and nothing is guaranteed. However given how well everything has gone on our build so far we kept our fingers crossed as the drilling started. Within a few hours I received the dreaded call from Phil Higgs of HM Construction https://www.hmconstructionuk.co.uk informing me that the drillers had found sand immediately under the surface. Sand is a major concern when drilling a borehole. If it is extensive it requires steel casing liners to be put in place to prevent the hole from collapsing inwards which is both time consuming and expensive. Phil said that Steve Templeman, from Orchard Drilling https://www.orcharddrilling.co.uk who was doing the work was hopeful that the sand would be just at the surface. Mark and I had a sleepless night as we wondered whether this would be a money pit rather than a borehole. Fortunately the next morning I received another call letting me know all was fine – they had rapidly drilled through the sand and there was no need for the casing.
Later that day I went down to visit the site to see the works for myself. To my surprise as I approached the house I could see water coming down the lane. When I got there Steve greeted me with a big grin and said he had hit water already, at a depth of only 10 foot. This was remarkable as the geological survey suggested we would have to drill down to around 65 meters to find the acquifier. To see the moment they hit water watch this clip: https://www.youtube.com/watch?v=AtN-sbBBrwQ
Steve continued to drill and the water continued to come faster and faster. He quickly concluded that we had an artesian well – which meant the water was actually under natural pressure from Mintern’s Hill behind the house – so was coming up to the surface of its own accord.
This was both good and bad news. The good news being that Steve estimates we have enough to water to supply the whole of the town….. but the bad news was that the pressure from the water meant it was collapsing the hole and preventing a clean supply. This meant Steve had to start steel lining the hole to strengthen it so we could get a stable supply. This took a couple of days and was very difficult but fortunately Steve was able to finally secure the water supply and the hole is now stable.
Steve drilled to 39m depth (although water was found at 5m); this should ensure that we are able to enjoy a continuous supply of water over the next 50 years even should the water table drop. This depth is considerably less than the original estimate that we would have to drill to 65m. The reduced drilling will help to balance out the costs of the steel casing.
We now have to test the water to see if it is drinkable. This is being done by Adrian and his team from ON TAP https://www.on-tap.co.uk. It entails fitting a temporary pump and running the water for 2 weeks. A sample will then be taken for testing which will take another two weeks. Only then will we know whether our water if fit to drink! So we wait again and are keeping everything crossed for a successful outcome.