Test 2 (Sewer Line) Flashcards
1
Q
Sewer Types
A
- Storm Sewer
- Sanitary Sewer
2
Q
Mains
A
- Collect from service lines - which service a single structure
3
Q
When are manholes required?
A
- At each change in direction
- At each change of grade/slope
- At junctions of mains
- At junctions of large service lines and mains 8” or larger service lines
- At 300’ to 400’ on straight runs
4
Q
Manhole Materials
A
- Precast Concrete (most common)
- Masonry
- Plastics
5
Q
Parging
A
- Pour 1” Portland concrete around the sloe to get soil in there to hold arch together
6
Q
Manhole Types
A
- Standard Manhole
- Drop Manhole
7
Q
Standard Manhole
A
- Provided a transition in the flow; also to provide a point of inspection and maintenance
- Influent - Flow of Flow Line
- Effluent - Flow line out
8
Q
- Drop Manhole
A
- Purpose is to provide transition, inspection and maintenance, to provide for minimum cover, to minimize depth of excavation & backfill
9
Q
Excavation
A
- Any man made removal of Earth’s surface
10
Q
Lift Station
A
- 1 Drop manhole
- Pump
- Purpose is to serve low cying area upstream, and to tie to existing mains
- Not going to be less than 5’6” between FL in and out
11
Q
Force Main System
A
- 2 Drop Manholes
- Pump (Lift Station)
- This is to service large sections
12
Q
Factors that affect the depth of a sewer line
A
- Minimum Course
- Frost Depth, Pressure on top of Pipe, Type of pipe
- Gravity Flow
- Max = 15%. Normal = < 8.00%
- Depth required to service area
- Depth of existing mains
- Depth of excavation & backfill
13
Q
Factors affecting selection of trench equip.
A
- Depth & Width of line (volume)
- Quantity of Materials
- Safety
- Type of Soil
- Type of Pipe
- Length of Open Trench
- Ground Water
- Width of right away/Easement laying the pipe backfill
- Currently owned Equipment
- Stream Crossing
- Vegetation
