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. Chlorination will kill or control these bacteria. Nuisance bacteria do not cause disease.
Chlorine helps remove manganese and hydrogen sulfide in the same way.
Iron and Manganese Removal. Chlorine will not remove nitrates from water. The claims of some water treatment firms imply that nitrates can be removed by chlorination. This is not true. However, if the concentration is great enough the water will taste bad so consumption may be reduced.