Wastewater Collector Class D License Chapter 4

Front 1

1. When planning collection system construction, inform utility companies and locate their
lines.
a. true
b. false

Back 1

a. true

Front 2

2. In a plan and profile drawings, existing utility lines and sizes, trench depth and new
wastewater line diameter are shown on the plan view.
a. true
b. false

Back 2

b. false

This is a trick question. it starts by referencing both plan and profile drawings... but ultimately is asking ONLY about the Plan View, Trench depth is only show on the profile drawings.

Front 3

3. Shoring includes hydraulic or screw jacks with metal bracing, timber and wood sheeting and
trench boxes.
a. true
b. false

Back 3

a. true

Front 4

4. Contractors working for a municipality are required by OSHA to shore.
a. true
b. false

Back 4

a. true

Front 5

5. Sloping or benching an excavation is an alternative to shoring.
a. true
b. false

Back 5

a. true

Front 6

6. Maximum allowable slope is expressed as the ratio of vertical rise to horizontal distance
(V:H)v.
a. true
b. false

Back 6

b. false

Not (V:H)

It's (H:V) Horizontal dist. to Verical rise is Maximum allowable slope

Front 7

7. Type B soil may include angular gravel, silt, silt loam, and previously disturbed soils except
those which would otherwise be classed as Type C soil.
a. true
b. false

Back 7

a. true

Front 8

8. The allowable slope for type B soil is 1:1.
a. true
b. false

Back 8

a. true

Front 9

9. Some considerations when selecting pipe includes exclusion of infiltration, external
pressure, industrial waste characteristics, corrosion and pipe joint length.
a. true
b. false

Back 9

b. false

Pipe Joint length is not related

Front 10

10. Types of pipe include vitrified clay, concrete, asbestos cement, plastic and ductile iron.
a. true
b. false

Back 10

a. true

Front 11

11. Vitrified clay pipe does not corrode, but root intrusion, cracking and infiltration are clay
pipe problems.
a. true
b. false

Back 11

a. true

Front 12

12. To protect concrete pipe from hydrogen sulfide, PVC liners, epoxy, coal tar coatings, or
excess concrete can be installed inside the pipe barrel.
a. true
b. false

Back 12

a. true

Front 13

13. While cutting or tapping asbestos-cement pipe, keep the pipe wall wet to avoid breathing
asbestos dust.
a. true
b. false

Back 13

a. true

Front 14

14. Plastic pipe has rigid walls and does not depend on bedding for support and strength.
a. true
b. false

Back 14

b. false

Plastic Pipe DOES depend on Bedding for support

Front 15

15. PVC pipe wall thickness is classified as Standard Dimension Ratio (SDR).
a. true
b. false

Back 15

a. true

Front 16

16. Prolonged exposure to hydrogen sulfide breaks down plastic pipe resins.
a. true
b. false

Back 16

b. false

Plastic pipe will no corrode.

Front 17

17. Ductile iron pipe is strong, but heavy and expensive.
a. true
b. false

Back 17

a. true

Front 18

18. When stringing pipe along the trench path, point the spigots away from the direction of
installation.
a. true
b. false

Back 18

b. false

When Stringing Pipe, the Spigots should point IN the (same) direction of installation (water flow).

Bells are up stream

Spigots are down stream

Front 19

19. If unloading pipe by hand, remove one piece at a time and do not stack pipe higher than 18
feet.
a. true
b. false

Back 19

b. false

Its 8ft NOT 18ft

When unloading by hand, remove one at a time and do not stack higher than 8ft

Front 20

20. Wastewater line grade must provide a velocity of at least 2 feet per second.
a. true
b. false

Back 20

a. true

Front 21

21. Two systems are generally used to set grade: string and rod, or razor beam.
a. true
b. false

Back 21

b. false

It's NOT RAZOR... it's LASER

READ THE QUESTIONS WELL...

Front 22

22. There are two general pipe loads: trench load and surface load.
a. true
b. false

Back 22

a. true

Front 23

23. The trench load decreases as the trench width, measured at the top of the pipe, increases.
a. true
b. false

Back 23

b. false

Trench load INCREASES as the Trench width increases.

Front 24

24. Trench width should be kept as narrow as possible, but the TCEQ requires trench width to
accommodate work, bedding and compaction equipment.
a. true
b. false

Back 24

a. true

Front 25

25. Lay pipe with the spigot pointing upstream and the bell pointing in the direction of flow.
a. true
b. false

Back 25

b. false

The Bell should point upstream

The Spigot should point in the direction of flow (downstream)

Front 26

26. Dig holes for the pipe bells so the barrel supports the pipe and do not lay pipe in water.
a. true
b. false

Back 26

a. true

Front 27

27. After work, leave the pipe end open and backfill first thing in the morning.
a. true
b. false

Back 27

b. false

After work SEAL the Pipe End and Backfill the Pipe as soon as possible or by the end of the day.

Front 28

28. ________ is required when the trench bottom is unstable.
a. Bedding
b. Foundation
c. Backfill
d. Shoring

Back 28

b. Foundation

Front 29

29. TCEQ requires pipe bells to be off the trench floor at least ________ inches and have at
least 6 inch clearance from the trench walls.
a. 2
b. 4
c. 6
d. 8

Back 29

c. 6

Front 30

30. Class A bedding for rigid pipe is achieved with the concrete ________ or ________.
a. bed/bend
b. sink/rise
c. cradle/arch
d. dip/dom

Back 30

c. cradle/arch

Front 31

31. Class B and C bedding for rigid pipe uses crushed stone, shell, gravel or ________.
a. clay
b. peat
c. coal
d. sand

Back 31

d. sand

Front 32

32. No rocks larger than ________ inches should be in the final backfill within ________ feet of
the pipe crown.
a. 6/3
b. 3/6
c. 3/3
d. 6/6

Back 32

a. 6/3

Front 33

33. The amount of deflection of plastic pipe depends on ________.
a. bedding compaction
b. trench conditions
c. pipe stiffness
d. all listed

Back 33

d. all listed

Front 34

34. Bedding material for plastic pipe includes ________.
a. gravel
b. sand
c. clay mixtures
d. all listed

Back 34

d. all listed

Front 35

35. Excessive trench load on plastic pipe requires pipe ________.
a. casing
b. bedding
c. roundness
d. stiffness

Back 35

a. casing

Front 36

36. Wastewater lines and manholes can be no closer to a water line than ________ feet.
a. 5
b. 6
c. 9
d. 10

Back 36

c. 9

Front 37

37. Parallel wastewater and water lines must be in ________ trenches.
a. deep
b. bedded
c. separate
d. shored

Back 37

c. separate

Front 38

38. Where wastewater lines or manholes cannot be separated from a water line by 9 feet, TCEQ
lists ________ alternative procedures.
a. two
b. three
c. four
d. five

Back 38

c. four

1) New installed Parallel (separate Trench)

2) New is to cross 2 ft below and at a 75 -90 degree angle

3) If Not 2ft below or less than 75 degree angle or pipe length is less than 18ft... then a Minimum distance of 6" below...

But if Pipe and joins are not pressure rated to 150 psi... that MUST be placed withing 9 ft of the waterline in all directions AND embedded in cement stabilized Sand (10% cement mix per yard of sand)

4) If a manholes is to be less than 9ft, the water line MUST be encased in new encasement at least 18ft long, with a psi of 150 and a diameter at least TWO sizes larger than the waterline.

Front 39

39. New ________ manholes are prohibited, and ________ cannot be used to adjust manhole
covers to grade.
a. brick/brick
b. concrete/brick
c. HDPE/fiberglass
d. brick/concrete

Back 39

a. brick/brick

Front 40

40. Operators should wear a safety harness with lifeline when entering a manhole and at least
________ persons should remain at the surface as standby help.
a. one
b. two
c. three
d. four

Back 40

b. two

Front 41

41. Ventilate by forcing ________ air into the manhole with a blower.
a. cool
b. warm
c. fresh
d. moist

Back 41

c. fresh

Front 42

42. Test the manhole for ________ with approved instruments.
a. gases
b. odor
c. temperature
d. roaches

Back 42

a. gases

Front 43

43. Install manholes at a change in pipe alignment, change in grade, change in pipe ________,
wastewater intersections and end of lines to be extended.
a. material
b. diameter
c. manufacturer
d. color

Back 43

b. diameter

Front 44

44. Manhole covers for new manholes must be ________ inches or larger.
a. 18
b. 20
c. 24
d. 30

Back 44

c.24 (??old ??)

But in the Book it says 30"

So I say the answer is d. 30

Front 45

45. ________ are prohibited in new manholes.
a. Vents
b. Steps
c. Laterals
d. Gases

Back 45

b. Steps

Front 46

46. Use a J-drop pipe if a wastewater line enters more than ________ inches above a manhole
invert.
a. 15
b. 20
c. 25
d. 30

Back 46

d. 30

Front 47

47. The soffit of a pipe is the pipe ________.
a. invert
b. bedding
c. foundation
d. crown

Back 47

d. crown

Front 48

48. A manhole fillet is a ________ invert.
a. curved
b. smooth
c. sloped
d. channeled

Back 48

c. sloped

Front 49

49. The total infiltration or exfiltration of a new system cannot exceed ________ gallons per
diameter inch of pipe/mile/________ hours at a minimum test head of ________ feet.
a. 50/12/2
b. 50/24/2
c. 24/50/2
d. 24/24/4

Back 49

b. 50/24/2

Front 50

50. Prior to an infiltration test, allow the ground water level to stabilize for ________ hours.
a. 12
b. 18
c. 24
d. 36

Back 50

c. 24

Front 51

51. Prior to an exfiltration test by water, fill the ________ manhole ________ feet above the top
of the pipe at its upper end, and then take measurements every ________ minutes.
a. lower/two/four
b. lower/four/five
c. upper/five/four
d. upper/two/five

Back 51

d. upper/two/five

Front 52

52. An exfiltration test by air requires that pipe less than ________ inch diameter be pressurized
to ________ psi greater than the pressure exerted by ground water above the pipe.
a. 36/3.5
b. 35/3.6
c. 24/3.5
d. 24/5.3

Back 52

a. 36/3.5

Front 53

53. ________ psi loss within the time limit fails an exfiltration test by air.
a. four
b. three
c. two
d. one

Back 53

d. one

Front 54

54. Deflection tests must be performed on ________ pipe.
a. all
b. concrete
c. plastic
d. clay

Back 54

c. plastic

Front 55

55. Pipe less than 27 inches in diameter must be tested with a ________ mandrel.
a. flexible
b. plastic
c. metal
d. rigid

Back 55

d. rigid

A mandrel's outside diameter must be equal to 95% of the indside diameter of the test pipe.

Its made of Metal or Plastic

It can withstand 200psi crush strength

Front 56

56. Deflection testing is conducted only after the final backfill is in place ________ days.
a. three
b. 30
c. 20
d. 15

Back 56

b. 30

Front 57

57. The mandrel cannot be pulled by a mechanical device and cannot exceed a ________
percent deflection.
a. three
b. four
c. five
d. six

Back 57

c. five

Front 58

58. The mandrel must have an outside diameter equal to ________ percent of the inside
diameter of the test pipe.
a. 95
b. 75
c. 25
d. 15

Back 58

a. 95

Front 59

59. The mandrel barrel must have a length at least ________ percent of the test pipe diameter.
a. 95
b. 75
c. 25
d. 15

Back 59

b. 75

Front 60

60. Pressure systems are useful in circumstances such as________.
a. high water table and hilly terrain
b. low population density
c. infiltration reduction
d. all listed

Back 60

d. all listed

Front 61

61. Pressure systems use submersible ________ pumps.
a. centrifugal
b. piston
c. diaphragm
d. screw

Back 61

a. centrifugal

Front 62

62. Multiple pump units are required for flow greater than ________ gallons per day.
a. 15
b. 150
c. 1,500
d. 15,000

Back 62

c. 1,500

Front 63

63. A visual and audio alarm is required for pressure system ________.
a. force mains
b. wet wells
c. check valves
d. control panels

Back 63

b. wet wells

Front 64

64. Like a pressure system, a ________ system collects wastewater in a sump often located on
private property.
a. vacuum
b. gravity
c. septic
d. private

Back 64

a. vacuum

Front 65

65. When the sump is full a switch ________ a valve to a ________under vacuum and the
wastewater is suctioned to a _______ point.
a. closes/pump/discharge
b. closes/pump/collection
c. opens/pipe/discharge
d. opens/pipe/collection

Back 65

d. opens/pipe/collection

Front 66

66. Vacuum pumps at collection points must empty the vacuum piping in ________ minute(s).
a. one
b. two
c. three
d. four

Back 66

c. three

Front 67

67. Duplicate vacuum pumps, each capable of ________% of specified airflow, are required.
a. 70
b. 80
c. 90
d. 100

Back 67

d. 100

Front 68

68. Alarms for ________ liquid level in the collection sump and ________ system vacuum are
required.
a. low/high
b. high/low
c. low/low
d. high/high

Back 68

b. high/low