Lesson 2: Water Supply Part 1

As you know from previous readings, the composition of soil is very important in the removal of both virus and bacteria. Which of the following soil conditions is most favorable for removal of viruses?

• sand over gravel

• fine loamy sand over coarse sand and gravel

• gravel over semi-porous clay

• coarse sand and gravel over fine sand or clay

Which of the following organisms are most resistant to unfavorable environmental conditions and indicate past or possibly intermittent pollution?

• fecal streptococci

• Escherichia coli

• Aerobacter aerogenes

• clostridium sporulates

Which of the following wells is considered the most dependable source of water and is less likely to become contaminated?

• driven well

• bored well

• drilled well

• dug well

Which of the following is not considered a satisfactory solution to the problem of chemical contamination in well systems?

• abandoning the well

• boiling the water

• connecting to a public water system

• building a new, properly constructed, drilled well

Which of the following chemicals is the most widely used to destroy microorganisms?

• chlorine

• copper sulfate

• chloramine

• hydrogen sulfate

Which of the following is the best method of backflow control?

• air gap separation

• vacuum breaker

• backflow preventer

• barometric loops

Microscopic photosynthetic plants of the simplest forms, having neither roots, stems, nor leaves, that are associated with taste and odor, filter clogging, and other water problems are know as

• yeasts

• algae

• protozoa

• rotifers

Control of infectious, intestinal diseases of humans requires

• provisions of safe water supplies

• proper waste disposal

• personal hygiene

• all of these

Drinking water standards generally specify that a water is safe provided that testing in a specified manner does not reveal more than an average of

• 10 positive samples out of 100 samples taken

• 50 coliform organisms per 100 ml

• 1 positive sample out of 40 samples taken

• 50 coliform organisms per 200 ml

What does it mean when a body of water has a high JTU?

• it has a low amount of organic matter

• it has no bacteria

• no one is swimming at this time

• it has high turbidity