Creating a water well isn’t as simple as drilling a hole until you reach water. Many factors go into building a successful water well and, unfortunately, there are some common themes that lead to water well failures, with design and construction at the top of the list.
Here are six prominent areas of concern that lead to the most common well failures:
- Seals: When state standards are used in construction over the geology of the well, inadequate seal depth is often directly traced to problems like nitrates and total coliform.
- Materials for Casing and Screen: Galvanic corrosion is a huge problem when trying to save money by using a stainless-steel screen and low-carbon steel casing. This will shorten the life of the well substantially and end up costing you in the long run.
- Gravel and Screen Size: The correct sizing of the screen and gravel can make all the difference in a successful water well. If the screen openings are too large and the gravel is the wrong size, you can end up with a sanding well and you’ll create an inefficient well by using a screen that has too-small openings.
- Bridging: Bridging can create voids when installing gravel pack during construction. When the amount of gravel used is inadequate and settles during development, dropping below the top of the upper screen, you can get the same bridging effect and cause later sanding issues.
- Welds: Corrosion of welds can cause well failure when different metal types are used. It’s important to conduct video logs after completion to verify construction and later video corrosion checks to catch any issues before failure can occur.
- Alignment and Plumbness: Problems with construction and pump operation arise when you drill a well that is not straight and plumb. Turbine pumps have more trouble with well deviation than a submersible pump would have, but poor alignment will almost always lead to well failure.
While these are common issues, according to the article in Worldwide Drilling Resource, they are also easily avoided. By taking geologic conditions into account during well design and focusing on the geology and aquifer characteristics when choosing a well location, you can head off these troubles and create an efficient and long-lasting water well.
