The correct answer is: A. Sanitary sewage.
A sanitary sewer is a type of sewer that carries wastewater from homes and businesses to a treatment plant. It is designed to carry only sanitary sewage, which is wastewater from toilets, sinks, and showers. Storm sewers, on the other hand, are designed to carry rainwater and runoff from streets and parking lots. Surface water is water that flows on the surface of the earth, such as in rivers, lakes, and streams. Groundwater is water that is stored underground in aquifers.
Sanitary sewers are typically made of concrete or clay, and they are buried underground. They have a slope that allows the wastewater to flow downhill to the treatment plant. Storm sewers are also typically made of concrete or clay, but they are often above ground. They have a grate or opening that allows the rainwater and runoff to flow into the sewer.
It is important to keep sanitary sewers and storm sewers separate. If sanitary sewage mixes with storm water, it can contaminate the water supply and cause health problems.