Aluminum is a soft, silvery metal commonly found in stormwater in both a dissolved (Al3+, Al(OH)4–) state and a particulate state. Aluminum is present in many soil types and minerals and is generally present in ground and surface water at low levels.[vii] Acid rain can dissolve aluminum in soils and transport it via runoff into water bodies in a dissolved state.[viii]
The primary uses of aluminum in industry include auto parts, beverage cans, home construction and aluminum foil.[xii] Aluminum compounds are added to sewage to facilitate phosphate removal and as part of the paper production process.[xiii] Aluminum in these forms can make its way into waterways and human freshwater drinking sources through stormwater runoff.