When most people think of industrial waste, they envision metal barrels with a hazardous waste symbol on the outside. There are many more sources of industrial waste than those pesky "hazardous wastes," and they hit a lot closer to home than you would think.
Much like the broadly defined industrial users (which were discussed in a the recent post "Water: Industrial Discharge Permits"), industrial waste is considered any discharge other than sanitary that is discharged into the sewer system. There are four basic types of industrial waste that enter into the sewer system: organic, inorganic, thermal and radioactive waste.
Organic waste comes from a variety of sources, but the main source of organic waste that is discharged into receiving streams is domestic wastewater. Other large contributors of organic waste comes from vegetable and fruit packaging, dairy processing, meat packaging, tanning, processing of poultry, oil, paper, and wood, in addition to many other industrial sources. Organic wastes are the main causes of oxygen depletion and the horrid odor in receiving streams and in wastewater streams.
Inorganic waste comes from many industrial facilities, domestic facilities, and nonpoint sources. Any chemical used in an industrial facility, including floor cleaners, scrubbers, acids, etc. are sources of inorganic wastes that can enter receiving streams. Soil, sand, and grit that is removed from the floor of a facility by a floor scrubber and washed down the drain are another source of inorganic waste from industrial facilities. Domestic facilities that use water softeners introduce a source of salt brine into receiving waters. Salt and other ice-melting agents that are put on the roads during snow or ice storms are a source of inorganic waste entering receiving streams by means of runoff, or entering through drainage pipes. Inorganic wastes are toxic to aquatic life and are to be kept out of receiving streams.
Thermal wastes come from cooling processes in facilities and from thermal plants that generate electricity. Often, enforcing agencies will require that thermal waste be cooled before it is introduced into a system since thermal waste can kill aquatic life.
Radioactive wastes are generally controlled as hazardous waste, but can sometimes enter into receiving waters and create problems for the surrounding areas. The main source of radioactive waste that enters receiving waters is from research facilities, hospitals, and power plants. Radioactive waste poses a danger to human, aquatic, and animal life.