Water Treatment ch 3

Question 1

Local conditions have little influence on the methods of managing lakes and reservoirs used for domestic water supplies

T or F?

Answer 1

False

Question 2

The amount and type of public use allowed on reservoirs has been standardized by law and regulations

T or F

Answer 2

False

Question 3

Few of the conditions which adversely affect water quality in domestic water supply reservoirs result from the impacts of man’s activities upon the environment

T or F

Answer 3

False

Question 4

Objectionable tastes and odors in domestic water supplies are often related to the occurrence of algal blooms.

T or F

Answer 4

True

Question 5

Many conventional water treatment plats are capable of reducing tastes and odors to acceptable levels when operated properly

T or F

Answer 5

True

Question 6

Algae can die of oxygen starvation

T or F

Answer 6

True

Question 7

In a monomictic lake, during winter months, the lake temperature is uniform from top to bottom

T or F

Answer 7

True

Question 8

Mixing occurs between the epilimnion and the hypolimnion zones in thermally stratified lakes

T or F

Answer 8

False

Question 9

Fish kills can result from algae clogging the gills of

T or F

Answer 9

True

Question 10

Once vegetation removal is accomplished at the reservoir site, regrowth should be controlled until the reservoir is filled.

T or F

Answer 10

True

Question 11

Chlorination of a water supply may either increase or decreased tastes and odors in drinking water

T or F

Answer 11

True

Question 12

The best tool which can be used for managing watersheds in most cases is the regulatory process

T or F

Answer 12

True

Question 13

Phosphate-base fertilizers usually do not cause the water quality problems caused by nitrogen fertilizers because of the soil-binding characteristics of phosphate compounds

T or F

Answer 13

True

Question 14

All algae react the same way to copper sulfate

T or F

Answer 14

False

Question 15

Destratification always increases the number of algae blooms in reservoirs

T or F

Answer 15

False

Question 16

With complete destratification, temperatures in a reservoir will be nearly uniform from top to bottom

T or F

Answer 16

True

Question 17

Through proper design and operation, reservoir destratification systems can be used to manipulate temperatures and dissolve oxygen content to desired levels

T or F

Answer 17

True

Question 18

The operator of a small water supply system must be able to manage the watershed as well as operators of large systems

T or F

Answer 18

True

Question 19

Records are very valuable only when they are completed and filed by lab personnel

T or F

Answer 19

False

Question 20

The inlet to a single-level intake is usually located near the water surface

T or F

Answer 20

False

Question 21

Nutrients act as a(n) __________ in a lake.

a) Algicide
b) Chemical stabilizer
c) Destratifier
d) Fertilizer
e) Purifier

Answer 21

d) Fertilizer

Question 22

Reservoirs which are rich in nutrients and very productive in terms of aquatic animal and plant life are commonly referred to as:

a) Dimictic
b) Eutrophic
c) Mesotrophic
d) Oligotrophic
e) Thermophylic

Answer 22

b) Eutrophic

Question 23

What problems may be created for operators by algal blooms in domestic water supply reservoirs?

a) Dissolved oxygen depletion
b) Increased pH which reduces chlorination efficiency
c) Increased organic loadings
d) Shortened filter runs
e) Tastes and odors

Answer 23

a, b, c, d, e

all correct

Question 24

What water quality problems are caused by iron and manganese in drinking water?

a) dirty water
b) dissolved oxygen depletion
c) high coliform counts
d) staining clothes
e) staining porcelain fixtures

Answer 24

a) dirty water

d) staining clothes
e) staining porcelain fixtures

Question 25

Proper management practices which can increase recreational values of a reservoir include a) Controlling man's activities on the watershed b) increasing the rate of oxygen depletion c) reducing large mats of algae d) reducing scums of algae e) removing vegetations before flooding

Answer 25

a) Controlling man's activities on the watershed c) reducing large mats of algae d) reducing scums of algae e) removing vegetations before flooding

Question 26

Trees and brush should be removed from areas to be flooded by reservoirs to reduce the _______ loading. a) iron and manganese b) nutrient c) organic d) silt e) turbidity

Answer 26

b) nutrient | c) organic

Question 27

Anaerobic conditions in the hypolimnion of a reservoir can cause a) algal scums b) fish kills c) high organic loadings d) iron and manganese problems e) rotten egg odors

Answer 27

b) fish kills d) iron and manganese problems e) rotten egg odors

Question 28

Algal blooms in lakes and reservoirs can be controlled by a) chemical methods b) limiting nutrient recycling c) preventing nutrient inflow d) removal of algae by filtration e) removal of nutrients by filtration

Answer 28

ANSWER PENDING

Question 29

Which of the following water quality indicators have a significant impact on the efficiency of copper sulfate as an algicide? a) alkalinity b) dissolved oxygen c) pH d) suspended matter e) water temperature

Answer 29

a) alkalinity c) pH d) suspended matter e) water temperature

Question 30

Which chemical is used to make copper sulfate effective in highly alkaline waters (greater than 150 mg/L alkalinity) a) citric acid b) hydrochloric acid c) nitric acid d) phosphoric acid e) sulfuric acid

Answer 30

a) citric acid

Question 31

The reasons for using destratification programs in a domestic water supply reservoirs include improving a) aesthetics b) fisheries c) hydroelectric power production d) recreational power power production e) water quality

Answer 31

a) aesthetics b) fisheries d) recreational power power production e) water quality

Question 32

Important water quality indicators that should be considered in a lake destratification program include a) carbon dioxide b) coliforms c) dissolved oxygen d) hardness e) temperature

Answer 32

c) dissolved oxygen | e) temperature

Question 33

Factors affecting watershed management programs include a) intake structure b) size of watershed c) topography d) vegetative conditions e) water quality problems

Answer 33

b) size of watershed c) topography d) vegetative conditions e) water quality problems

Question 34

Which of the following watershed practices can affect water quality in a water supply reservoir? a) control of land use b) livestock grazing c) oil and gas exploration and drilling d) septic tank leaching systems e) soil conservation programs

Answer 34

a) control of land use b) livestock grazing c) oil and gas exploration and drilling d) septic tank leaching systems e) soil conservation programs

Question 35

Water quality laboratory analysis which may be best performed by commercial laboratories include a) dissolved oxygen b) pesticides c) radioactivity d) temperature e) trihalomethanes

Answer 35

b) pesticides c) radioactivity d) temperature e) trihalomethanes

Question 36

Intake facilities should prevent _______ from entering a water supply system. a) algal scums b) fish c) hardness d) iron and manganese e) tastes and odors

Answer 36

a) algal scums | b) fish

Question 37

Water quality problems caused by anaerobic water entering the intake-inlet include high concentrations of: a) dissolved oxygen b) hardness c) hydrogen sulfide d) iron e) manganese

Answer 37

c) hydrogen sulfide d) iron e) manganese

Question 38

Types of intake screens include a) burlap sacks b) slotted c) vee wire d) window screens e) woven wire

Answer 38

b) slotted c) vee wire e) woven wire

Question 39

Methods of cleaning intake screens include a) brushing with bristle brushes b) drying and brushing c) jetting with high pressure d) reversing the slow e) vacuuming up the debris

Answer 39

a) brushing with bristle brushes c) jetting with high pressure d) reversing the slow

Question 40

Factors that can adversely affect water quality in lakes and reservoirs include a) agriculture runoff b) drainage from mining areas c) grazing of livestock d) logging operations e) runoff from urban areas

Answer 40

a) agriculture runoff b) drainage from mining areas c) grazing of livestock d) logging operations e) runoff from urban areas

Question 41

Objectionable tastes and odors in a domestic water supply may be caused by a) algae b) hardness c) hydrogen sulfide d) overturns e) photosynthesis

Answer 41

a) algae c) hydrogen sulfide d) overturns

Question 42

Trihalomethanes are often formed during chlorination by reactions with a) acid rain b) ammonia c) iron and manganese d) natural organic materials e) nutrients

Answer 42

d) natural organic materials

Question 43

Purposes of reservoir management programs include a) improvement and maintenance of fishery values b) improvement and maintenance of recreational values c) improvement and maintenance of water quality d) improvement and maintenance of watershed aesthetics e) reduction of water treatment costs

Answer 43

a) improvement and maintenance of fishery values b) improvement and maintenance of recreational values c) improvement and maintenance of water quality e) reduction of water treatment costs

Question 44

What is the surface area of a rectangular setting basin 60ft long and 15 wide? a) 90 sq ft b) 360 sq ft c) 400 sq ft d) 500 sq ft e) 900 sq ft

Answer 44

e) 900 sq ft

Question 45

What is the surface area of a circular clarifier 40 feet in diameter a) 314 sq ft b) 1,256 sq ft c) 1,600 sq ft d) 2,512 sq ft e) 5,024 sq ft

Answer 45

b) 1,256 sq ft

Question 46

Calculate the volume cubic ft, of a rectangular setting basin 8 ft deep, 15 ft wide, and 60 ft long a) 120 cu ft b) 480 cu ft c) 900 cu ft d) 4,800 cu ft e) 7,200 cu ft

Answer 46

e) 7,200 cu ft

Question 47

Calculate the volume in a cubic feet of a circular clarifier 7 feet deep and 40 feet in diameter. a) 7,200 cu ft b) 8,800 cu ft c) 11,200 cu ft d) 24,800 cu ft e) 35,200 cu ft

Answer 47

b) 8,800 cu ft

Question 48

How many pounds of copper sulfate will be needed to dose a reservoir with 0.5 mg/L copper? The reservoir volume is 20 million gallons. The sulfate is 25 percent copper. a) 125 lbs b) 165 lbs c) 335 lbs d) 835 lbs e) 1,335 lbs

Answer 48

c) 335 lbs