Which information should be included in the driller's log for monitoring well construction?

• A. Depth to bedrock
• B. Odors from cuttings
• C. Depth to water
• D. Loss of drilling fluid

Answer: (C)

The main idea is that the driller’s log should capture where groundwater is encountered and how the water table behaves during construction. Depth to water is recorded because it tells you exactly how far below the surface the water-bearing zone sits at each stage of drilling, which directly informs how deeply you place casing and screens and how you seal the borehole to prevent returns or contamination. It also provides a baseline for future pumping tests and for understanding the well’s potential yield.

Other observations like odors from cuttings, depth to bedrock, or loss of drilling fluid can be noted, but they don’t directly indicate the groundwater level and its pressure conditions, which is why depth to water is the most critical piece of information to include for monitoring well construction.