Downhole video analysis of water supply wells: problem identification and well rehabilitation

Methods to improve groundwater quality or declining well yield begin with an analysis of the well environment. The dynamic conditions within a borehole and surrounding groundwater reservoirs correlate with functional, geological, biological, and chemical factors within. Water discoloration and turbidity, along with smell and taste, are the first warning signs of well problems. Key indicators of well dysfunction are degradation in water quality and declining well yield. A water well is an active environment and is best interpreted through direct observation during periods of static rest, pumping stress, and recharge. Pumping influences groundwater by creating decreased pressure along preferential pathways away from the well. When these pathways occur too shallow or along high angle fractures, unfiltered near-surface water is pulled down into the well bore. Often, near-surface water is high in nutrients and supports rapid growth of bacteria within the well. Downhole video cameras allow for direct observation and characterization of the inside of the water well.