Iron Removal Water Filter Plant Next to hardness, the presence of iron is probably the most common water problem faced by consumers and water treatment professionals. The maximum secondary contaminant levels for iron and manganese are 0.3 mg/l and 0.05 mg/l, respectively. Iron and manganese in excess of the suggested maximum contaminant levels usually result in discoloration of water, laundry, and plumbing fixtures. Rusted and damaged pipelines are a major cause of iron in the water. The presence of iron in water can pose considerable design, cost, and operational issues to industrial processes. Netsols iron removal solutions provide an effective, cost-efficient approach to removing iron from water.