How often do we think about where the water comes from when we open the tap, fill a glass and gulp it down?
Until now, we have watered the trees and other plants with sloshing buckets lugged with a yoke from our little pond. We have watered the greenhouse with snow melt. We have hauled water from our house in Madison. We have washed up at the end of hot, sweat days by spraying each other with the backpack sprayers that we use for controlled prairie burns.
And we have sometimes been very thirsty when we underestimated how much drinking water to bring on a given day.
But those days will soon be history because last week, Sam’s Well Drilling http://www.samswelldrilling.com/spent 2 days sinking a shaft 145 feet into the ground near our house site. It was impressive and mesmerizing to watch.
Two massive trucks pulled up our drive and backed up to the chosen spot. Since the process results in a slurry of ground up rock coming out of the well hole, they built an impromptu berm of dirt and stone on the downhill side to keep that glop away from our stacked wood and the pond.
They cranked the well drilling tower into position. They jacked the truck up into the air until the well rig was exactly perpendicular. . It was not long before the drilling began.
When Dean Rickard and his son Jason started drilling, they were cutting into that geological history looking for a water-bearing formation.
Last January I heard the director of the UW-Madison Geology Museum, Richard Slaughter, describe what is under our feet in the Dirftless Area to the Blue Mounds Area Project. http://www.bluemounds.org/ . He said that the rock under this area came from the Ordovician period some 450 million years ago. http://science.nationalgeographic.com/science/prehistoric-world/ordovician/
For the most part, the earth was warm and wet then. Wisconsin was looking up at the sky through about 100 feet of water and was located near the equator. Sea levels were 600 meters higher than they are today, and those seas were teaming with life. Shelled squids were the top predator. Bony armor was all the rage, and those countless shells formed a lime-rich calcium carbonate mud on the sea floor that eventually hardened into sandstone and limestone
It takes water to make water. One of the drilling trucks hauls 2,000 gallons in a tank under the rack where the steel well casing is carried. Dean and Jason used it all before our well was done.
The water is pumped down into the hole and flushes out what the bit grinds up.
Dean and Jason were watching closely to read the clues coming up to them.
They regularly slipped a special basket under the outflow and studied each sample it to see what they were drilling through.
They were looking for a water-bearing formation at least 60 feet thick, a. They drilled through a layer of blue clay shale. The water extracted from shale can come out of your spout looking milky.
Dean and Jason put in extra steel casing to make sure that shale stays out of our drinking water.
Then, praise be, they came to a magnesium limestone layer that makes an excellent source of drinking water. At 145 feet they hit more blue shale and decided to quit while they were ahead. Dean said that having our aquifer protected above and below by layers of shale should bode well for its purity. After all, these shale layers contain a lot of clay, and that stuff is impervious to water-borne contaminants. We’ll know more about that when the water quality tests come back.
Once the well was deep enough, they started putting the steel casings down, and welding each to the one below it as they went.
Steel pipe called well casing must always be placed in the top part of the well hole to prevent surface water from getting into the well. Sometimes the casing is needed to keep it from caving in.
The diameter of the drilled hole is wider than the diameter of the casing, and the surrounding space has to be filled to keep ground water from getting down into the well and contaminating it. In our case they poured down a three-inch thick collar of cement.
Dean said it would take about 30 bags of cement for this job. Unlike concrete, their cement is mixed only with water, no sand and no gravel, and as it came out of the concrete truck, Dean puts it through a final sieve because even small lump could clog the hoses he uses to run it deep into the ground.
Jason predicted it would set up over night, and create a lot of heat in the process.
Just before all the concrete was pumped into the ground, some unexpected air pressure built up from a subterranean pocket, and wet concrete belched back out, covering Jason and splattering Dean. They both made quick use of some of that 2,000 gallons flushing the concrete off their skin. Jan, the concrete truck driver, had some soft absorbent cloths in her cab, which she calmly provided as they worked to get the concrete out of their eyes and ears before it could harden.
Evidently, this happens now and then.
When they were done, the only sign that a hole had been drilled 145 feet into the ground was the slurry-coated driveway, and a neatly-capped piece of steel pipe sticking up about 4 feet out of the ground.
They rumbled down the drive and on to their next job, drilling over a hundred wells that will support the geothermal heating and cooling of a new building at the University of Dubuque in Iowa – an hour away on the other side of the Mississippi.
There was a moment of surprised silence. The birds and frogs filled it in with their calls almost instantly.
At one point in the afternoon, I got to see the first water from our well brim out and run down the drive. We won’t see any more of it till the well pump is lowered to the bottom of that long dark shaft, and the plumbing and electricity are installed in the house. Probably another week or so.
I can hardly wait to taste our good well water.