Dug vs. Drilled Wells: Which Is Right for Your Home?

Digging a deep hole seems pretty straightforward, but not all wells are created equal. When it comes to digging vs. drilling a well, you can expect a number of important differences beyond the effort of shoveling dirt or dealing with a few hours of drilling. Understanding the differences between the two options is the first step in preparing to dig your own well.

What Are the Differences Between Dug Wells and Drilled Wells?

The main difference between dug and drilled wells is, of course, the excavation method. Beyond using a shovel or heavy machinery, dug and drilled wells differ pretty dramatically in terms of depth, water quality, reliability, and cost. 

Dug vs. Drilled Well: Differences in Well Depth

Dug wells are shallow, typically between 10 and 50 feet deep and about 3 feet wide. Since they’re dug by hand with either a shovel, backhoe, auger, or drive point, dug wells can’t be excavated deeper than 50 feet without a need for machinery.

In comparison, drilled wells can be drilled more than 1,000 feet deep. In residential settings, drilled wells are usually between 100 and 200 feet in depth and about 6 inches in diameter. The actual depth of a drilled well depends on factors such as the water table, water quality, contamination risk, and geology. 

Dug vs. Drilled Well: Differences in Construction

Since they don’t go beyond 50 feet, dug wells rely on traditional excavation methods as part of their construction. Dug by hand with a shovel, backhoe, or auger until the water table is reached, dug wells are then lined and reinforced with stone, tile, brick, or other sturdy materials. A sanitary cap made of stone, wood, or concrete is installed to help reduce contamination risk

If your well is designed to be deeper than 50 feet, it requires drilling for construction. Using a drill rig with either a rotary or percussion drill bit, your local well contractor can create a small borehole in the ground. Once the appropriate depth is reached, a tube-shaped well casing made of either steel or plastic is installed in the well and sealed with grout or bentonite clay to help keep dirt and excess water out.

Dug vs. Drilled Well: Differences in Water Quality

Regardless of the type of well, proper well construction, location, and testing are important for the safety and quality of your water. The deeper the well is, however, the lower the risk of water contamination. 

Dug wells are inherently at a higher risk for contamination as they source water from shallow water tables, which are more susceptible to hazardous groundwater runoff from various sources such as sewage, agriculture, construction sites, industry, and more. This can result in potentially harmful contaminants, including:

• Bacteria

• Viruses

• Parasites

• Heavy metals

• Chemicals

• Vermin

Drilled wells are far less prone to groundwater runoff contaminants due to their depth and continuous casing design, but they can carry their own risks. Drilling so far into the earth means your water source may contain chemical or mineral additives, which is why deep wells require screens and casing to keep sediment out.

Dug vs. Drilled Well: Differences in Water Level

Depending on where you live and seasonal weather fluctuations, the depth of your well can have a big impact on your well’s water levels. Since dug wells can only access shallow depths, they rely on aquifers that are more likely to fluctuate in water levels through the year and may even have extended dry spells. 

In comparison, drilled wells can provide reliable water year-round regardless of dry seasons. The actual depth required to reach a reliable aquifer can vary—sometimes 100 feet is adequate, and sometimes you’ll have to drill several hundred feet to find a good water source.

Dug vs. Drilled Well: Differences in Cost

While location, geology, and casing can influence the final cost of a well, the main cost factors are the depth of the well and whether you’ll need drilling equipment or not. 

Since dug wells are always shallow, they’re almost always cheaper to build than drilled wells. With about $25 per foot at the high end, the most you can expect to pay for digging a well is $1,250. The lower cost per foot for a dug well is due to fewer materials and machinery, and you can save on labor costs even further by making it a weekend DIY project.

Even if a drilled well isn’t much deeper than a dug well, either renting a drill rig for a DIY project or hiring a local professional for the job increases the final bill. Since the final depth can vary depending on aquifer availability, drilling costs can range from $1,800 to $24,500.