25) Well Capping and a Minor Disaster - December '17
On December 7th, the well drillers returned install the geothermal loop and to 'cap' the well. 700 feet of two inch pipe is pushed down each casing, ultimately they will be joined together, filled with glycol and tied into the heat pump. The fluid circulates through the loop, bringing up heat from down deep and into the utility room where it is extracted by the heat pump. From there it circulates inside the house through the three zones of the subfloor radiant heat pipes.
Once installed the wells need to be capped, which involves pumping a clay-like natural substance called sodium bentonite into the casing. This amazing material is non-soluable and expands over time completely closing up the inside of the well. Here the crew prepares to begin pumping:
Here's a pic of the internal loop pipes coming out of the casing. Some overflow was expected but it appears something unusual happened, it kept flowing. For days. It just wouldn't stop. Apparently drilling the wells had opened up a vein of pressurized water that was rising up outside of the casing...
To keep the runoff out of the stream, we led the overflow to the garden, where any solids could settle. It'll be interesting to see if the 'sodium' in sodium bentonite will affect the fertility of the soil. Who knows, maybe it'll be beneficial?
Stone is being poured into the well to try to stanch the flow. It didn't work.
Even worse, water started flowing out of the top of our main house's wellhead! You can see it here. The guys took the top off the wellhead to allow the water to flow into a trench into the back yard. Prior to that the water was flowing through the electrical conduit into our basement.
The well drillers were amazed by what was happening. Quite unusual they said. Often in Vermont it's tough to find water, but we were blessed with the opposite, while some folks have to drill over 1000 feet to find water, we had two wells outflowing at the surface. We're hoping that the flow will stop over time...
