Through the direct discharge of their process wastewater.
Through storm water which comes into contact with chemicals and other pollutants at the site and then washes offsite.
Most all industries are aware that the direct end of pipe discharge of wastewater from their industrial process requires a permit, issued by the state (or, if the discharge is to the city's sanitary sewer system, issued by the city's pretreatment section). However, many industries may not be aware that storm water runoff from their facility is also subject to regulation.
Storm water flows over and through an industrial facility, picking up pollutants from outdoor spills and leaking or dirty objects and taking these pollutants to our bayous, lakes, and rivers.
Industrial Facility Pollution Control Requirements
Federal, state, and city regulations now require certain classes of industries to obtain storm water permits and to implement pollution prevention practices.