The primary difference between a drilled well and a driven well lies in their construction method, depth, cost, and water yield potential.
A driven well is typically constructed by driving a small-diameter pipe, usually with a screen point at the end, into the ground using a maul or a power driver. This method is suitable for areas with soft, sandy soil and a shallow water table, often less than 50 feet deep.
In contrast, a drilled well is created using a rotary drill rig or a cable tool rig, which bores a much larger hole into the ground. This method can penetrate various types of soil and rock layers and reach deeper aquifers, often hundreds of feet down.
Key Differences Highlighted
Based on the provided reference and common understanding, here are the key distinctions:
- Installation Method: Driven wells are physically driven into the ground, while drilled wells are bored using specialized equipment.
- Cost & Ease: Driven wells are easy to install and are less costly when compared to drilled wells. This makes them an attractive option for landowners.
- Pipe Size: Driven wells use pipes with a small size, which also makes it easy to install just about anywhere on your property. Drilled wells use larger diameter pipes (typically 4 to 8 inches or more).
- Depth & Water Source: Driven wells tap into shallow water tables and are limited by the depth of the soft soil. Drilled wells can reach much deeper aquifers, providing a more reliable and potentially higher-quality water source in areas with deeper bedrock.
- Water Yield: Due to their smaller diameter and shallower depth, driven wells typically have a lower water yield compared to drilled wells, which can access larger volumes of water from deeper sources.
- Safety: They can also be safer to operate when compared to dug and drilled wells, as the sealed pipe prevents surface contamination more effectively than a dug well and involves less complex, heavy machinery than drilling.
Comparative Overview
Here is a table summarizing the main differences:
| Feature | Driven Well | Drilled Well |
|---|---|---|
| Installation | Driven into the ground | Bored using a drill rig |
| Cost | Lower cost, easy to install | Higher cost, requires specialized equipment |
| Depth | Shallow (typically < 50 ft) | Deep (can be hundreds of feet) |
| Pipe Size | Small diameter (small size of the pipe) | Larger diameter |
| Soil Type | Best for soft, sandy soil | Suitable for various soil and rock types |
| Water Yield | Generally lower yield | Generally higher yield and more reliable |
| Safety | Can be safer to operate against contamination | Requires complex installation, deeper source benefits |
| Location | Easy to install just about anywhere | Requires access for large drill rig |
Choosing between a drilled and driven well depends heavily on local geology, water needs, and budget. Driven wells are suitable for low-volume needs in areas with shallow, accessible groundwater, while drilled wells are necessary for reaching deeper, more consistent water sources needed for larger demands.
