I read an interesting article recently about the use of shock chlorination for maintaining a well. There are several types of bacteria that can cause contamination in wells with the most common being iron and sulfate-reducing bacteria. While the presence of these bacteria apparently does not pose a health problem, the bacterial growth can coat the inside of the well casing, water piping and pumping equipment. The end result of such a coating can be a bad smell (rotten eggs), a restricted water flow in the distribution lines, staining of plumbing fixtures and laundry and the plugging of water treatment equipment. This is something to consider for those individuals already using a well and for prospective purchasers of a property where the water source is a well.