Waste water can be defined as any water that has been contaminated in some way by human use, whether from domestic, industrial, commercial, or agricultural sources. Waste water from domestic household activities is known as sewage.

Industrial waste water is generated by a wide variety of industries and their activities, including: processing waters; cooling waters; waters used in hydraulic fracturing; waste from food, beverage, pharmaceutical, chemical, and pesticide manufacturing; and water by-products of oil and natural gas production.

Depending upon the source, waste water can contain various types of chemical, biological, and physical pollutants. Proper management of waste water requires its careful collection and treatment before reuse or disposal.

Waste water treatment consists of various processes to remove contaminants to produce an effluent that can be returned to the water cycle. For example, common waste water treatment processes include: phase separation, such as sedimentation; biological and chemical treatments, like oxidation; and polishing.

Bayport Technical's Waste Water Working Demonstrator (102-WWT) is a training aid designed to give maintenance and operations personnel in waste water treatment facilities an introduction to the workings and various methods of modern waste water treatment. For example, students or workers using the Waste Water Working Demonstrator will gain valuable experience with real industrial waste water treatment equipment, such as reservoirs, clarifier tanks, pumps, aerators, and air compressors.