Wells 101: What Happens Next?

It’s my favorite moment from any drilling day: that moment when the drill hits water, and it comes pouring out the top of the pipe.

I love it.

But if you look closely, you’ll see that the water isn’t really drinkable yet. It’s murky, mixed with drilling “mud” that keeps the bit lubricated so it doesn’t overheat, and silty from particulates in the groundwater. So what does it take to make the well actually provide drinking water?

A fully functioning well has several critical components. A casing extends from the ground surface to just below the top of the water table, and keeps contaminants from the surface from leaching into the aquifer. The casing serves as a conduit so we can bring water to the surface without compromising the rest of the surrounding geology.

At the bottom of the casing, the driller attaches a length of slotted screen, which allows water to pass into the well, but keeps larger particles of sand and clay out of the water column.

The slotted screen is surrounded by a two-inch gravel pack, which helps keep water moving through the screen without being impeded by smaller sediments. As the well is developed over the first 24 hours, the water becomes less cloudy and more like the drinking water we’re used to seeing from our taps.

Finally, a pump is lowered into the water column to move the water to the surface. Depending on the depth of the water, that pump might be a hand pump, a riser pump, or an electric pump with a 2- or 3-horsepower motor. Water from the hand pumps can go directly into a bucket, and water in electric wells typically goes to a tank, where it is gravity-fed to taps that people can access whenever they need. Pumps can be removed from the well periodically for maintenance and to replace worn-out parts.

These are just a few of the steps that go into making a well function. A well is a miracle of technology, bringing clean water from deep underground to the surface where people can benefit from it!