How many collection system classifications are there and which are they?

• A. Three: Sanitary, Industrial, Storm
• B. Four: Sanitary, Industrial, Storm, Combined
• C. Four: Sanitary, Storm, Industrial, Wastewater
• D. Five: Sanitary, Industrial, Storm, Combined, Reclaimed

Answer: (B)

The main idea is that sewer systems are classified by the type of wastewater they convey. There are four recognized categories: sanitary sewers for household and commercial wastewater, storm sewers for rainfall runoff, combined sewers that carry both sanitary and storm water, and industrial sewers that handle industrial process wastewater. This fourth category recognizes that industrial wastes often require separate management or pretreatment due to pollutants that may not be present in domestic or rainfall flows.

So this option is best because it names all four distinct types typically used to describe collection systems. The other choices omit a category (the combined system), replace a category with an uncommon term (Wastewater), or add a concept that isn’t a collection-system type (Reclaimed, which refers to reuse rather than how sewer lines are classified).