If a test indicates that your water is contaminated you should locate the source of pollution and eliminate it from your water supply. Testing to detect iron and manganese is not normally done until these minerals have been detected either by sight or by taste. Disease-causing bacteria may enter your well during construction, repair, flooding or as a result of improper construction. Proper chlorination will kill these bacteria. If disease-causing bacteria enter your water supply on a continuous basis, you must eliminate the source or construct a new water supply.
Iron bacteria feed on the iron in the water.
They may appear as a slimy, dark-red mass in the toilet tank but microscopic examination is needed to confirm their presence. Iron bacteria colonies may break loose from the inside of pipes and flow through faucets to cause stains in laundry, plumbing fixtures, etc. A thorough shock chlorination of the well and water system may destroy all iron bacteria colonies. In this situation you will need to repeat chlorination treatment periodically. Other nuisance organisms include slime bacteria and sulfate reducing bacteria which produce a rotten-egg odor.