1. What is the wastewater flow in a sewer system during the periods of dry weather with minimum infiltration called?
a) Wet weather flow
b) Dry weather flow
c) Wet flow
d) Dry flow
Explanation: Summers are usually dry. Hence the rainfall is minimum and is called as dry weather flow in sewers. During the rainy season or periods of high rainfall or storm, the sewers will be full and are called wet weather flow.
2. In order to determine the section of the sewer, it is essential to know the total quantity of the sewage that would flow through the sewer.
a) True
b) False
Explanation: The quantity of sewage that would flow in dry weather is different from the quantity of the sewer that would flow in the wet weather. Hence peak conditions must be considered and sewer size should be determined
3. The dry weather flow is also called as sanitary sewage.
a) True
b) False
Explanation: Dry weather flow mainly consists of domestic sewage and industrial wastewater as the rainfall or storm is absent or less in the times of summer of dry weather. Hence dry weather flow is also called as sanitary sewage.
4. Which of the following factors does the dry weather does not depend on?
a) Rate of water supply
b) Population growth
c) Infiltration of groundwater
d) Design of sewer system
Explanation: Dry weather flow depends on the type of area served, rate of water supply, population growth, infiltration of groundwater. Design of sewer system is to determine the size of a sewer system in peak conditions. It has nothing to do with the factors responsible for dry weather flow.
5. Which of the following common unit is used to express the rate of water supply to a city or town?
a) Litres/capita/second
b) Litres/capita/day
c) Millilitres/capita/day
d) Millilitres/capita/hour
Explanation: The common unit used to express the rate of water supply to a city or town is in terms of litres per person for a day. Capita refers to each person or an individual. Hence the unit is litres/capita/day.
6. The quantity of sanitary sewage entering the sewers would be ___________ the total quantity of water supplied.
a) Less than
b) Equal to
c) More than
d) Greater than
Explanation: The quantity of sanitary sewerage entering the sewers would be less than the total quantity of water supplied because the water is lost in domestic consumption, evaporation, lawn sprinkling, fire fighting and industrial consumption.
7. The quantity of sanitary sewage directly depends on ______
a) Rate of water supply
b) Area
c) Population
d) Precipitation
Explanation: As the population increases the rate of water consumption also increases which leads to the direct increase in sanitary sewage. This also increases water demand. Hence the quantity of sanitary sewage directly depends on the population.
8. The quantity of water supply is equal to the rate of supply multiplied by the ______.
a) Population
b) Quantity of sewage
c) Area
d) Net usage
Explanation: The rate of usage of water varies from individual to individual and different sectors. Hence the total quantity of water supplied is equal to the rate of supply multiplied by population.
9. Wet weather flow is _________ than the dry weather flow.
a) Lower
b) Higher
c) Equal to
d) Not equal to
Explanation: Wet weather flow is higher than the dry weather flow because of the inflow and infiltration in the sewer system. Wet weather flow is the combination of stormwater and sanitary sewage but dry weather flow consists of only sanitary sewage.
10. Dry weather flow+ storm water=_________
a) Dry weather flow
b) Stormwater
c) Wet weather flow
d) Sanitary sewage
Explanation: Dry weather flow is the wastewater flow in sewers during dry weather. Dry weather flow in combination with stormwater is called as wet weather flow.