Application of Well Condition Assessment and Rehabilitation Techniques +CD-ROM

The emphasis of this project was the renovation of wells with regard to water yield. Techniques that were potentially suitable for renovation of wells with respect to contamination and clogging of the well screens were also to be identified and addressed. Similarly, well-maintenance procedures to prevent reduced water yield or decreased water quality were to be investigated. The decline in production efficiency of water-supply wells has been a long-term concern of water utilities. Typical responses to this problem include redevelopment of wells, aquifer fracturing, drilling of new wells, or employing various rehabilitation techniques. Unfortunately, redevelopment of wells is often a temporary remedy because aquifer fracturing can destroy the well installation, installation of new wells is expensive, and rehabilitation techniques are not always successful in restoring wells to their former yields. There have been recent advances in water treatment techniques, as well as in subsurface well-rehabilitation techniques, that should be studied in detail to determine their strengths, weaknesses, and potential applications. The quality of water in wells is often compromised by deterioration of the well head or well-casing materials. The deterioration of these portions of a well installation may allow a direct hydraulic connection of two separate water-bearing layers, or it can allow surface water and surface-water runoff to channel down along the well casing and directly impact the aquifer water quality. A number of recent outbreaks of enteric disease in the United States and the United Kingdom have been traced to compromised well heads and well casings.