Lesson 2: Water Supply Part 3

Turbidity of water will

• interfere with proper disinfection

• harbor viruses

• cause tastes and odor

• all of these

This substance is the first product of the decomposition of organic matter. Its presence in water usually indicates "fresh pollution" of sanitary significance. What is it?

• ammonia

• sugar

• carbon dioxide

• hydrogen sulfide

The presence of which of the following elements in water treatment plant effluent is used as a measure of filtration efficiency?

• copper

• aluminum

• zinc

• lead

One of the most common reasons for the contamination of wells drilled through rock, clay, or hardpan is

• seepage of pollutants through soil

• failure to seal well casings properly

• porosity of the rock

• use of inferior quality well casings

Proper disinfection of water using chlorine depends on the concentration of chlorine plus which of the following?

• temperature of the water

• pH of the water

• contact period

• all of these

Which of the following is used to control the growth of algae and protozoa?

• addition of copper sulfate

• aeration of the water

• addition of nitrates

• filtration

The gases frequently found in water that encourage corrosion are

• methane and oxygen

• oxygen and carbon dioxide

• chlorine and carbon dioxide

• methane and hydrogen sulfide

In emergencies, small quantities of water can be disinfected by boiling or using

• aluminum salts

• tincture of iodine

• salt tablets

• direct exposure to sunlight for 22 hours

Which of the following is not used to disinfect water?

• chlorine

• bromine

• fluorine

• iodine

Porosity is

• a measure of the amount of water that can be held by a rock in its pores or voids, expressed as a percentage of the total volume

• the amount of water that will drain out of saturated rock or soil by gravity

• the direct relationship between permeability and specific yield