Water that (i) is or has been used in an industrial or manufacturing process, (ii) conveys or has conveyed sewage, or (iii) is directly related to manufacturing, processing or raw materials storage areas at an industrial plant. Wastewater does not include water originating on or passing through or adjacent to a site, such as storm water flows, that (i) has not been sued in industrial or manufacturing processes, (i) has not been combined with sewage, (iii) or is not directly related to manufacturing, processing or raw materials storage areas at an industrial plant.

http://www.emgcorp.com/whatshot/dictionary.php