Driven wells are practical only when the water-bearing formations are relatively close to the surface and no contaminants exist in the soil. Which statement best describes this condition?

Driven wells are practical only when the water-bearing formations are relatively close to the surface and no contaminants exist in the soil. Which statement best describes this condition?

• A. They are simple to install and require the formations to be within 150 ft of the surface with no contaminants
• B. They are relatively cost effective to install, within 80 ft of the surface and no contaminants exist
• C. They are simple to install, but contaminants must be present to support flow
• D. They are relatively cost effective to install, and contaminants near the surface are acceptable

Answer: (B)

Driven wells are the simplest and most cost-effective option when the water source is close to the surface and the surrounding soil is clean. Because the well draws water from shallow formations, contaminants in near-surface soil can more easily enter the well water, so a clean soil environment is essential to protect water quality. The practical limit is a shallow water-bearing formation—about 80 feet from the surface—combined with no contaminants in the soil. Deeper depths like 150 feet aren’t typical for driven wells, and allowing or requiring surface contaminants would defeat the purpose of the well. So the statement that best fits is that they’re simple and cost-effective to install within about 80 feet of the surface with no contaminants present.

Driven wells are the simplest and most cost-effective option when the water source is close to the surface and the surrounding soil is clean. Because the well draws water from shallow formations, contaminants in near-surface soil can more easily enter the well water, so a clean soil environment is essential to protect water quality. The practical limit is a shallow water-bearing formation—about 80 feet from the surface—combined with no contaminants in the soil. Deeper depths like 150 feet aren’t typical for driven wells, and allowing or requiring surface contaminants would defeat the purpose of the well. So the statement that best fits is that they’re simple and cost-effective to install within about 80 feet of the surface with no contaminants present.