Let’s jump right back in where we left off last week. If you missed it, I highly recommend you checking out last week’s blog entitled “Water Wells 101”. I gave an overview of wells, how they work and what they do. I mentioned there are different types but left you all in suspense. Well here we are, at the exciting conclusion to a two-part nail-biter of a blog miniseries! Read on!
One type of well are called DRIVEN wells-a small diameter pipe with a screened well point on the bottom is driven in the ground. These wells are relatively simple and economical to construct, but they can tap only shallow water and are easily contaminated from nearby surface sources because they are not sealed with grouting material. Hand-driven wells usually are only around 30 feet deep; machine-driven wells can be 50 feet deep or more. We see these wells in areas with a high water table such as the Eastern Shore.
And there are hand dug wells. Historically, dug wells were excavated by hand shovel to below the water table until incoming water exceeded the digger’s bailing rate. The well was lined with stones, bricks, tile, or other material to prevent collapse, and was covered with a cap of wood, stone, or concrete tile. Because of the type of construction, bored wells can go deeper beneath the water table than can hand-dug wells. Dug and bored wells have a large diameter and expose a large area to the aquifer. These wells are able to obtain water from less-permeable materials such as very fine sand, silt, or clay. Disadvantages of this type of well are that they are shallow and lack continuous casing and grouting, making them subject to contamination from nearby surface sources, and they go dry during periods of drought if the water table drops below the well bottom. There are still some active hand dug wells around. We have a customer with a dug well that is about 8’ in diameter and 60’ or so deep. It is lined with stone and their pump just hangs in the water; it’s a little scary to work on that well. Years ago, my dad had a customer in Randallstown with a hand dug well. According to the homeowner, it had been hand-dug by slaves in 1850. It was about 30’ deep, 5’ in diameter and lined with some of the most beautiful stonework you’d ever see. That well continuously produced water…never went dry. Unfortunately, the homeowner passed away, the property sold and the well filled in. I think it was a historical artifact.
So, there you go: a brief lesson on wells. Before we get into well pumps, I think we’ll talk a little about well water quality next week.
Until then, GO ORIOLES!