Which characteristic may be observed to determine proper development of a groundwater monitoring well?

• A. Temperature
• B. Turbidity
• C. pH
• D. Color of water

Answer: (B)

During well development, you’re trying to flush drilling fluids and fine sediments out of the screen so the aquifer connects cleanly to the well. Turbidity directly measures the amount of suspended solids in the water, so it’s the best indicator of how well those fines are being removed. If turbidity is high, solids are still being drawn into the screen; as development continues, turbidity should decrease and the water should become clearer, signaling that the screen and surrounding formation are being properly cleaned and the well is hydraulically well-connected. Temperature, pH, and water color can be influenced by many factors and don’t reliably show the progress of development; they don’t specifically track the removal of suspended fines like turbidity does.