ABSTRACT
When a sudden cloud of sand and debris plugs the prefilter system, and a production well corresponding ceases to function, it is likely that the well has failed. A slow decline in the water level in a production well can be indicative of a regional aquifer problem or a problem in the well. The continuing entry of formation material, such as quartz sand, clay, or carbonate mud, may be indicative of a problem in the well. In wells used to supply conventional water treatment plants, chlorine can be pumped directly into the production formation to control growth. The well is then developed with compressed air to remove the chlorine and bacterial mass. When a white or black organic material fouls the prefilters, there is a good possibility that bacteria are fouling the production aquifer. Most production wells tend to yield some minor quantities of particulate material during the operation.
