Iron should be removed from stormwater because excessive amounts in drinking water and the environment can cause harm to human health and wildlife habitat. Although iron is an essential mineral, diseases of aging such as Alzheimer’s disease, other neurodegenerative diseases, arteriosclerosis, diabetes mellitus, and others have been linked to excess iron intake.[i] High concentrations of iron in drinking water can produce an unpleasant taste and stain home fixtures.[ii]
While iron in in trace amounts is an essential dietary mineral for fish and other animals as it is for humans, iron toxicity has been observed in certain fish species at concentrations in excess of 1,380 mg iron/kg in their diet.[iii]
Indirectly, iron can kill fish by causing algae blooms, which create biological oxygen demand[iv], smother aquatic plants and produce potent neurotoxins.[v] Even low concentrations of iron (0.1-1.0 mg/L) may cause nuisance algae species to replace inoffensive species[vi], adversely affecting fish habitats.