Which of the following is NOT an example of a non-residential source of sanitary sewage?

• A. Office building
• B. School
• C. Apartment
• D. Hospital

Answer: (C)

Non-residential sources are buildings whose primary purpose isn’t to provide housing; they include places like offices, schools, and hospitals where people come to work, learn, or receive care. The wastewater from these sources comes from occupants who don’t live there permanently and from the activities that happen in those facilities, such as office use, classrooms, patient care, kitchens, and cafeterias. An apartment, on the other hand, is a dwelling where people live as their residence, so the wastewater produced there is residential in nature. Because apartments are residential rather than non-residential, they are the item that is not an example of a non-residential source.