water treatment distribution and system design wqt 121 lecture 4 awwa. 2006. chapter 1: introduction...
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Water Treatment Distribution and System Design
Water Treatment Distribution and System Design
WQT 121
Lecture 4AWWA. 2006. Chapter 1: Introduction to Distribution System
Design, 3rd ed
WQT 121
Lecture 4AWWA. 2006. Chapter 1: Introduction to Distribution System
Design, 3rd ed
Week Objectives Week Objectives
1. Understand Operators Role in Distribution
2. Understand types of water systems and water system planning.
3. Understand main sizing, pressure, velocity, and piping materials
1. Understand Operators Role in Distribution
2. Understand types of water systems and water system planning.
3. Understand main sizing, pressure, velocity, and piping materials
Reading assignment: Handouts: Transmission and Distribution Pipelines AWWA. 2006. Ch1 Water Transmission and Distribution
Reading assignment: Handouts: Transmission and Distribution Pipelines AWWA. 2006. Ch1 Water Transmission and Distribution
Water distribution systems consists of pipes, storage facilities, pumping station,
valves, fire hydrants, meters and other appurtenances?
Water distribution systems consists of pipes, storage facilities, pumping station,
valves, fire hydrants, meters and other appurtenances?
Tru
e
Fal
se
0%0%
1. True
2. False
1. True
2. False
Key WordsKey Words
• Surface Water Systems: Treatment and use of surface water to supply industries and domestic residences.
• Groundwater Systems: Groundwater extracted for the sole purpose of supply.
• Purchased Water Systems: A water utility that purchases water from another entity (may be contaminated or cant meet demand).
• Rural Water Systems: Located in rural areas and may be many miles away from customers. They can use surface or groundwater for supply.
• Surface Water Systems: Treatment and use of surface water to supply industries and domestic residences.
• Groundwater Systems: Groundwater extracted for the sole purpose of supply.
• Purchased Water Systems: A water utility that purchases water from another entity (may be contaminated or cant meet demand).
• Rural Water Systems: Located in rural areas and may be many miles away from customers. They can use surface or groundwater for supply.
Key WordsKey Words• Dead ends Single main that is difficult to repair and maintain proper flow
(should be avoided in water supply)
• Shut Off Valves Necessary for easy access to repair and maintain a water system.
• Main Sizes – Must be sized to meet the peak domestic, commercial, and industrial demands in the area to be served.
• Water Distribution System – made up of pipes, valves, and pumps which treated water is moved from treatment plant to consumers. A system includes water treatment facilities, water meters, water storage and fire protection.
*** Want sufficient volume at adequate pressure.***
• Dead ends Single main that is difficult to repair and maintain proper flow (should be avoided in water supply)
• Shut Off Valves Necessary for easy access to repair and maintain a water system.
• Main Sizes – Must be sized to meet the peak domestic, commercial, and industrial demands in the area to be served.
• Water Distribution System – made up of pipes, valves, and pumps which treated water is moved from treatment plant to consumers. A system includes water treatment facilities, water meters, water storage and fire protection.
*** Want sufficient volume at adequate pressure.***
Operators Role in DistributionOperators Role in Distribution
1. Operate system to maintain water quality, positive pressures, and control water velocity and direction
2.Maintain pipes, valves, pumps, to ensure flow
3.Operate system to accommodate demand
4. Install connection to new users
5.Maintain main line and customer water meters.
1. Operate system to maintain water quality, positive pressures, and control water velocity and direction
2.Maintain pipes, valves, pumps, to ensure flow
3.Operate system to accommodate demand
4. Install connection to new users
5.Maintain main line and customer water meters.
Operators Role in DistributionOperators Role in Distribution6.Read meters
7.Sample and maintain water quality
8.Operate a cross connection control program
9.Maintain maps and records
10.Keep up to date on new technologies
11.Recommend repairs, replacements, or improvements.
12. Provide good safe clean drinking water
6.Read meters
7.Sample and maintain water quality
8.Operate a cross connection control program
9.Maintain maps and records
10.Keep up to date on new technologies
11.Recommend repairs, replacements, or improvements.
12. Provide good safe clean drinking water
The average amount of water used per person per day is: The average amount of water used per person per day is:
a. 2
5-30
gpd
b. 5
0-60
gpd
c. 7
5-10
0 gpd
d. 1
00-1
50 g
pd
0% 0%0%0%
a. 25-30 gpd
b. 50-60 gpd
c. 75-100 gpd
d. 100-150 gpd
a. 25-30 gpd
b. 50-60 gpd
c. 75-100 gpd
d. 100-150 gpd
The utility’s annual average day demand is determined by
dividing the?
The utility’s annual average day demand is determined by
dividing the?
a. W
ater
use
p...
b. T
otal w
ater
...
c. W
ater
use
p...
d. A
vera
ge d
ay...
0% 0%0%0%
a. Water use per month by the number of days in that month
b. Total water use for a year by 365 days
c. Water use per week by seven days
d. Average day demand by the number of residents
a. Water use per month by the number of days in that month
b. Total water use for a year by 365 days
c. Water use per week by seven days
d. Average day demand by the number of residents
Public relations are important because we:
Public relations are important because we:
Wan
t to fi
nish o
ur wo..
Don't
wan
t to b
e la
te f.
.
Hat
e lis
tenin
g to w
hi...
Must
dea
l with
the
pu...
Wan
t to k
eep o
ur jobs
0% 0% 0%0%0%
1. Want to finish our work in a hurry
2. Don't want to be late for lunch
3. Hate listening to whiners
4. Must deal with the public
5. Want to keep our jobs
1. Want to finish our work in a hurry
2. Don't want to be late for lunch
3. Hate listening to whiners
4. Must deal with the public
5. Want to keep our jobs
The primary role of a water operator is?
The primary role of a water operator is?
Avo
id b
oil ord
ers
Tes
t the
wat
er
Tre
at th
e w
ater
Pro
vide
safe
cle
an w
a...
0% 0%0%0%
1. Avoid boil orders
2. Test the water
3. Treat the water
4. Provide safe clean water that is free of bacteria and toxic chemicals
1. Avoid boil orders
2. Test the water
3. Treat the water
4. Provide safe clean water that is free of bacteria and toxic chemicals
Operators of water distribution systems are responsible for? Operators of water distribution systems are responsible for?
Saf
e dr
inki
ng wat
er t.
..
Kee
ping
prepar
ed fo
r...
Oper
atin
g and m
aint
...
All
of the
above
0% 0%0%0%
1. Safe drinking water to everyone
2. Keeping prepared for the future
3. Operating and maintaining systems
4. All of the above
1. Safe drinking water to everyone
2. Keeping prepared for the future
3. Operating and maintaining systems
4. All of the above
Successful communication requires mutual:
Successful communication requires mutual:
Agre
emen
t
Confu
sion
Tra
nsmis
sion
Under
stan
ding
0% 0%0%0%
1. Agreement
2. Confusion
3. Transmission
4. Understanding
1. Agreement
2. Confusion
3. Transmission
4. Understanding
The best approach to complaints involving the operation of a
water plant is to:
The best approach to complaints involving the operation of a
water plant is to:
Exp
lain
the
proble
m ..
.
Kee
p all
perso
ns e
xce.
.
Nev
er a
dmit
ther
e is
...
Public
ize
the
prob
le...
0% 0%0%0%
1. Explain the problem and proposed solution and offer to conduct a tour of the plant for those complaining
2. Keep all persons except for operating personnel out
3. Never admit there is a problem or cause for the complaint
4. Publicize the problem as much as possible
1. Explain the problem and proposed solution and offer to conduct a tour of the plant for those complaining
2. Keep all persons except for operating personnel out
3. Never admit there is a problem or cause for the complaint
4. Publicize the problem as much as possible
If a water supply exceeds the MCL, whose responsibility is it to
notify the consumer?
If a water supply exceeds the MCL, whose responsibility is it to
notify the consumer?
the
test
ing la
b.
the
supplie
r.
the
DOH
the
USEPA
0% 0%0%0%
1. the testing lab.
2. the supplier.
3. the DOH
4. the USEPA
1. the testing lab.
2. the supplier.
3. the DOH
4. the USEPA
Surface Water SystemsSurface Water Systems
• Surface water sources are open to contamination from human and animal waste and other pollution.
•Must comply with the federal Surface Water Treatment Rule (SWTR) and include filtration, disinfection, operating, monitoring, and reporting requirements.
•Water is always treated prior to distribution
•Treatment for Microorganisms, turbidity, and must have a minimum disinfectant residual.
• Surface water sources are open to contamination from human and animal waste and other pollution.
•Must comply with the federal Surface Water Treatment Rule (SWTR) and include filtration, disinfection, operating, monitoring, and reporting requirements.
•Water is always treated prior to distribution
•Treatment for Microorganisms, turbidity, and must have a minimum disinfectant residual.
Case Study: Willamette River Water Treatment Plant
Wilsonville, OR
Case Study: Willamette River Water Treatment Plant
Wilsonville, OR
•Intake Screens in Willamette River•Intake Screens in Willamette River
Case Study: Willamette River Water Treatment Plant
Wilsonville, OR
Case Study: Willamette River Water Treatment Plant
Wilsonville, OR • Opened April 2002
•Can process 15 million gallons per day (mgd).
•Low of approximately 2 mgd in the winter to nearly 6 mgd in the peak of the summer.
•City's water system includes storage tanks throughout town with a total combined capacity of nearly 11 million gallons.
•Wilsonville's former water supply (a system of 8 local wells) is also available for use in emergencies.
• Opened April 2002
•Can process 15 million gallons per day (mgd).
•Low of approximately 2 mgd in the winter to nearly 6 mgd in the peak of the summer.
•City's water system includes storage tanks throughout town with a total combined capacity of nearly 11 million gallons.
•Wilsonville's former water supply (a system of 8 local wells) is also available for use in emergencies.
Case Study: Willamette River Water Treatment PlantWilsonville, OR
Case Study: Willamette River Water Treatment PlantWilsonville, OR
Enhanced Sedimentation PhaseEnhanced Sedimentation Phase
coagulants and fine sandcoagulants and fine sand
Clarified waterClarified water
Case Study: Willamette River Water Treatment PlantWilsonville, OR
Case Study: Willamette River Water Treatment PlantWilsonville, OR
OzonationOzonationLiquid OxygenLiquid Oxygen
Converts O2 gas to O3 (ozone)Converts O2 gas to O3 (ozone)
Case Study: Willamette River Water Treatment PlantWilsonville, OR
Case Study: Willamette River Water Treatment PlantWilsonville, OR
Granular Activated CarbonGranular Activated Carbon6 feet of charcoal w/1ft sand remove residual turbidity, pathogens, organic chemicals, and taste/odor compounds
6 feet of charcoal w/1ft sand remove residual turbidity, pathogens, organic chemicals, and taste/odor compounds
Case Study: Willamette River Water Treatment PlantWilsonville, OR
Case Study: Willamette River Water Treatment PlantWilsonville, OR
Chlorine DisinfectionChlorine Disinfectionmaintain disinfection as the water is pumped through pipes to customers at the far ends of the City's water distribution system. maintain disinfection as the water is pumped through pipes to customers at the far ends of the City's water distribution system.
Groundwater SystemsGroundwater Systems
• Groundwater extracted for the sole purpose of supply.
•May not require treatment
• Space wells so don’t need large transmission pipes
• Groundwater extracted for the sole purpose of supply.
•May not require treatment
• Space wells so don’t need large transmission pipes
Purchased Water SystemsPurchased Water Systems
• Groundwater or surface water supply becomes inadequate (West Linn & Lake Oswego)
• Contamination
• Operator may not need to treat
• Good quality water
• Must be good accountants
• Groundwater or surface water supply becomes inadequate (West Linn & Lake Oswego)
• Contamination
• Operator may not need to treat
• Good quality water
• Must be good accountants
Rural Water SystemsRural Water Systems• Supplies water to remote regions
• Can be groundwater or surface water supply
• Fire protection can be limited
• Supplies water to remote regions
• Can be groundwater or surface water supply
• Fire protection can be limited
Water System Planning IssuesWater System Planning Issues• Water availability
• Source reliability
• Water quality
• Location
• State and Federal requirements
• Water availability
• Source reliability
• Water quality
• Location
• State and Federal requirements
The size of water mains, pumping stations, and storage tanks is primarily determined
by?
The size of water mains, pumping stations, and storage tanks is primarily determined
by?
Max
imum
day
de.
..
Popul
atio
n ser
...
Per
-cap
ita w
at...
Fire
pro
tect
io...
0%
33%
0%
67%
1. Maximum day demand during any 24 hour period during the previous year
2. Population served
3. Per-capita water use
4. Fire protection requirements
1. Maximum day demand during any 24 hour period during the previous year
2. Population served
3. Per-capita water use
4. Fire protection requirements
Why is excessive water pressure to residential homes
objectionable?
Why is excessive water pressure to residential homes
objectionable?
Incr
ease
s pa
rt...
Cau
ses
erosi
on...
Dec
reas
es th
e ...
Cau
ses
foam
ing...
14%7%
64%
14%
1. Increases particulate matter reaching customer
2. Causes erosion of copper plumbing due to the high velocities, giving the water a metallic taste
3. Decreases the life of water heaters and other water bearing appliances
4. Causes foaming of faucets
1. Increases particulate matter reaching customer
2. Causes erosion of copper plumbing due to the high velocities, giving the water a metallic taste
3. Decreases the life of water heaters and other water bearing appliances
4. Causes foaming of faucets
Policy ConsiderationsPolicy Considerations• Current and future growth
• Costs
• Financing Methods
• Zoning and Ordinances
• Regulatory Issues
• Current and future growth
• Costs
• Financing Methods
• Zoning and Ordinances
• Regulatory Issues
Which of the following are important for system layout Which of the following are
important for system layout
A. p
lanni
ng th
e sy
stem
,
B. c
onfig
uring a
sys
tem
,
C. m
appin
g a
syst
em,
D. c
hoosi
ng a v
alve
...
E. A
ll of t
he a
bove
0% 0%
96%
4%0%
A. planning the system,
B. configuring a system,
C. mapping a system,
D. choosing a valve arrangement
E. All of the above
A. planning the system,
B. configuring a system,
C. mapping a system,
D. choosing a valve arrangement
E. All of the above
What are some of the programs and operational procedures that can be
implemented by water utilities to help ensure the delivery of the best water
quality to the consumers?
What are some of the programs and operational procedures that can be
implemented by water utilities to help ensure the delivery of the best water
quality to the consumers?
A. E
stab
lish a
...
B. F
lush
the
s...
C. M
onitor w
at...
D. A
ll of t
he ..
.
0%
100%
0%0%
A. Establish a cross connection control program and maintain system pressure over 30 PSI,
B. Flush the system periodically and maintain the highest possible disinfectant residual at all times
C. Monitor water quality throughout the distribution system, and take actions when observing signs of water quality deterioration
D. All of the above
A. Establish a cross connection control program and maintain system pressure over 30 PSI,
B. Flush the system periodically and maintain the highest possible disinfectant residual at all times
C. Monitor water quality throughout the distribution system, and take actions when observing signs of water quality deterioration
D. All of the above
System LayoutSystem Layout• Plan and Configure
•Arterial-large mains surround system
•Grid-All mains interconnected, water from several locations
•Tree-water starts with transmission main and branches off
• Map and Size
• Plan and Configure •Arterial-large mains surround system
•Grid-All mains interconnected, water from several locations
•Tree-water starts with transmission main and branches off
• Map and Size
Which of the following is a distribution layout pattern?Which of the following is a distribution layout pattern?
Den
driti
c G
rid
Par
alle
l
Bru
sh
0% 0%0%
100%1. Dendritic
2. Grid
3. Parallel
4. Brush
1. Dendritic
2. Grid
3. Parallel
4. Brush
Complaints of poor water quality will most likely occur in which
type of main layout?
Complaints of poor water quality will most likely occur in which
type of main layout?
Arte
rial L
oop
Tre
e G
rid
Neb
ular
0% 0%0%
100%1. Arterial Loop
2. Tree
3. Grid
4. Nebular
1. Arterial Loop
2. Tree
3. Grid
4. Nebular
An arterial-loop distribution system has flow from how many
directions?
An arterial-loop distribution system has flow from how many
directions?
1 2 3 4
17%
67%
11%6%
1. 1
2. 2
3. 3
4. 4
1. 1
2. 2
3. 3
4. 4
Dead EndsDead Ends• Dead End Mains
• Restricted flow because of one main
• Water can become stagnant or degrade
• All customers beyond repair point lose water access when main is fixed.
(a) In order to provide increased reliability of service and reduce head loss, dead ends shall be minimized by making appropriate tie-ins whenever practical.
(b) Where dead-end mains occur, they shall be provided with a fire hydrant if flow and pressure are sufficient, or with an approved flushing hydrant or blow-off for flushing purposes. Flushing devices shall be sized to provide flows which will give a velocity of at least 2.5 fps in the water main being flushed. No flushing device shall be directly connected to any sewer.
• Dead End Mains• Restricted flow because of one main
• Water can become stagnant or degrade
• All customers beyond repair point lose water access when main is fixed.
(a) In order to provide increased reliability of service and reduce head loss, dead ends shall be minimized by making appropriate tie-ins whenever practical.
(b) Where dead-end mains occur, they shall be provided with a fire hydrant if flow and pressure are sufficient, or with an approved flushing hydrant or blow-off for flushing purposes. Flushing devices shall be sized to provide flows which will give a velocity of at least 2.5 fps in the water main being flushed. No flushing device shall be directly connected to any sewer.
What water quality problem is most likely to occur at dead-end
mains?
What water quality problem is most likely to occur at dead-end
mains?
Dirt
y w
ater
Tas
te a
nd odor
Milk
y wat
er d
u...
Dirt
y cl
othe
s ...
22%
0%0%
78%
1. Dirty water
2. Taste and odor
3. Milky water due to air bubbles
4. Dirty clothes due to manganese
1. Dirty water
2. Taste and odor
3. Milky water due to air bubbles
4. Dirty clothes due to manganese
MappingMapping• Existing System
• Existing and planned streets
• Expansion areas
• All topographic and subsurface features
• Population densities and predictions
• Normal water consumptions
• Proposed additions or changes
• Existing System
• Existing and planned streets
• Expansion areas
• All topographic and subsurface features
• Population densities and predictions
• Normal water consumptions
• Proposed additions or changes
ValvingValving• Need shutoff valves (repair and maintenance) •Valves shall be located at not more than 500 foot intervals in commercial districts and at not more than one block or 800 foot intervals in other districts. Where systems serve widely scattered customers and where future development is not expected, the valve spacing shall not exceed one mile.
• Air and vacuum at high points• The air relief valve should be placed so as to prevent problems due to freezing. A shut-off valve should be provided to permit servicing of any air relief valve.
• Blowoff valves at low points
• Backflow prevention devices
• Need shutoff valves (repair and maintenance) •Valves shall be located at not more than 500 foot intervals in commercial districts and at not more than one block or 800 foot intervals in other districts. Where systems serve widely scattered customers and where future development is not expected, the valve spacing shall not exceed one mile.
• Air and vacuum at high points• The air relief valve should be placed so as to prevent problems due to freezing. A shut-off valve should be provided to permit servicing of any air relief valve.
• Blowoff valves at low points
• Backflow prevention devices
The sudden closure of a check valve will result in
The sudden closure of a check valve will result in
wat
er h
amm
er
flow re
vers
al
cav
itatio
n
wat
er a
erat
ion...
81%
0%5%
14%
1. water hammer
2. flow reversal
3. cavitation
4. water aeration
1. water hammer
2. flow reversal
3. cavitation
4. water aeration
MainsMains• Must supply for fire flow requirements (Fire insurance code) and domestic use
• High value districts (8-12”), Residential (6-8”)
Sized to meet peak demandsFor water mains not connected to fire hydrants, the minimum line size shall be 4-inch diameter. Minimum water main size serving a fire hydrant lateral shall be 8-inch diameter unless a hydraulic analysis indicates that required flow and pressures can be maintained by smaller lines.
Guidance: Generally, velocity in a water main should not exceed 5 fps. Mains should be designed with sufficient excess capacity to provide for anticipated future connections.
• Must supply for fire flow requirements (Fire insurance code) and domestic use
• High value districts (8-12”), Residential (6-8”)
Sized to meet peak demandsFor water mains not connected to fire hydrants, the minimum line size shall be 4-inch diameter. Minimum water main size serving a fire hydrant lateral shall be 8-inch diameter unless a hydraulic analysis indicates that required flow and pressures can be maintained by smaller lines.
Guidance: Generally, velocity in a water main should not exceed 5 fps. Mains should be designed with sufficient excess capacity to provide for anticipated future connections.
Pipes of dissimilar metal should not be connected together
because of problems due to
Pipes of dissimilar metal should not be connected together
because of problems due to
1. s
cale
form
a...
2. c
orrosi
on
3. w
ater
ham
me.
..
4. t
he v
entu
ri...
0% 0%0%
100%1. scale formation
2. corrosion
3. water hammer
4. the venturi effect
1. scale formation
2. corrosion
3. water hammer
4. the venturi effect
Fire HydrantsFire Hydrants The design of the distribution system shall be consistent with Appendix B of the 2003
International Fire Code. As specified in this code, minimum fire-flow requirements are: 1. 1000 gpm for one- and two-family dwellings with an area of less than 3600 square feet.2. 1500 gpm or greater for all other buildings.3. Average spacing between hydrants must be no greater than 500 ft. Guidance: Generally, individual hydrant spacing may range from 350 to 500 feet depending
on the area being served. Hydrants should be provided at each street intersection and at intermediate points between intersection. The planning of hydrant locations should be a cooperative effort between the water utility and local fire officials.
4. Exceptions can be granted
5. Water mains not designed to carry fire flows shall not have fire hydrants connected to them.
6. The design engineer shall verify that the pipe network design permits fire-flows to be met
at representative locations while minimum pressures as required by R309-105-9 are maintained at all times and at all points in the distribution system.
Guidance: For guidance on conducting this analysis, refer to AWWA Manual M31,
Distribution System Requirements for Fire Protection. 7. As a minimum, the flows to be assumed during a fire-flow analysis shall be the "peak day
demand" plus the fire flow requirement.
The design of the distribution system shall be consistent with Appendix B of the 2003 International Fire Code. As specified in this code, minimum fire-flow requirements are:
1. 1000 gpm for one- and two-family dwellings with an area of less than 3600 square feet.2. 1500 gpm or greater for all other buildings.3. Average spacing between hydrants must be no greater than 500 ft. Guidance: Generally, individual hydrant spacing may range from 350 to 500 feet depending
on the area being served. Hydrants should be provided at each street intersection and at intermediate points between intersection. The planning of hydrant locations should be a cooperative effort between the water utility and local fire officials.
4. Exceptions can be granted
5. Water mains not designed to carry fire flows shall not have fire hydrants connected to them.
6. The design engineer shall verify that the pipe network design permits fire-flows to be met
at representative locations while minimum pressures as required by R309-105-9 are maintained at all times and at all points in the distribution system.
Guidance: For guidance on conducting this analysis, refer to AWWA Manual M31,
Distribution System Requirements for Fire Protection. 7. As a minimum, the flows to be assumed during a fire-flow analysis shall be the "peak day
demand" plus the fire flow requirement.
When using a fire hydrant, the valve:
When using a fire hydrant, the valve:
should
nev
er b
...
2. b
e open
ed o
...
3. b
e open
ed t.
..
4. b
e open
ed a
...
5%
70%
20%
5%
1. should never be opened completely
2. be opened only during the hours of 8 AM to 5 PM
3. be opened to the desired amount of flow
4. be opened all of the way
1. should never be opened completely
2. be opened only during the hours of 8 AM to 5 PM
3. be opened to the desired amount of flow
4. be opened all of the way
The primary reason for dry barrel fire hydrants is to:
The primary reason for dry barrel fire hydrants is to:
allo
w eas
y m
ai...
pre
vent w
ater
...
kee
p the
hydra
...
kee
p the
barr
e...
17%
0%
83%
0%
1. allow easy maintenance
2. prevent water hammer
3. keep the hydrant from freezing
4. keep the barrel from rusting
1. allow easy maintenance
2. prevent water hammer
3. keep the hydrant from freezing
4. keep the barrel from rusting
Main PressureMain Pressure
• The distribution system shall be designed to maintain minimum pressures as required in R309-105-9 (at ground level) at all points of connection, under all conditions of flow, but especially during peak day flow conditions, including fire flows.
•Guidance: The normal working pressure in the distribution system should be between 40 and 60 psi. When static pressure exceed 80 psi, pressure reducing devices should be provided on mains in the distribution system, or individual home pressure reducing valves should be installed per the Utah Plumbing Code.
• The distribution system shall be designed to maintain minimum pressures as required in R309-105-9 (at ground level) at all points of connection, under all conditions of flow, but especially during peak day flow conditions, including fire flows.
•Guidance: The normal working pressure in the distribution system should be between 40 and 60 psi. When static pressure exceed 80 psi, pressure reducing devices should be provided on mains in the distribution system, or individual home pressure reducing valves should be installed per the Utah Plumbing Code.
•Minimum static pressure 35 psi (High fire flow)
• During use not drop below 20 psi
•Residential water pressure 50-75 psi
•Minimum static pressure 35 psi (High fire flow)
• During use not drop below 20 psi
•Residential water pressure 50-75 psi
Which of the following does not affect the friction loss in a given
length of pipe?
Which of the following does not affect the friction loss in a given
length of pipe?
1. h
ardnes
s of
...
2. n
umber
of f
...
3. r
oughnes
s o...
4. v
eloci
ty o
f...
58%
21%
0%
21%
1. hardness of the water
2. number of fittings
3. roughness of the interior of the pipe
4. velocity of the flow
1. hardness of the water
2. number of fittings
3. roughness of the interior of the pipe
4. velocity of the flow
From a sanitary standpoint, the pressure in a distribution system should never be allowed to fall to
zero because
From a sanitary standpoint, the pressure in a distribution system should never be allowed to fall to
zero because
1. l
ow p
ress
ur...
2. g
round
wat
e...
3. t
he c
hlorin
...
4. t
he m
ain m
a...
18%
0%6%
76%
1. low pressure allows bacteria to multiply
2. ground water may enter and back siphonage may occur
3. the chlorine residual will drop faster
4. the main may collapse
1. low pressure allows bacteria to multiply
2. ground water may enter and back siphonage may occur
3. the chlorine residual will drop faster
4. the main may collapse
Main Velocity and MaterialsMain Velocity and Materials• Minimum 5 ft/sec• What are a materials strength, pressure rating, durability, corrosion resistance, smoothness of inner surface, ease of tapping and repair, maintenance?
•External load- pressure on pipe from ground after burial•Internal load -hydrostatic pressure of water within pipe
• Pipes should be rated at 2.5-4 times pressure rating of system)
•PVC, Iron, Steel, Concrete
• Minimum 5 ft/sec• What are a materials strength, pressure rating, durability, corrosion resistance, smoothness of inner surface, ease of tapping and repair, maintenance?
•External load- pressure on pipe from ground after burial•Internal load -hydrostatic pressure of water within pipe
• Pipes should be rated at 2.5-4 times pressure rating of system)
•PVC, Iron, Steel, Concrete
Polyethylene pipe material will reduce water loss, is economical, and is capable of handling a variety of
environmental conditions from extreme cold, earthquakes and corrosive materials.
Polyethylene pipe material will reduce water loss, is economical, and is capable of handling a variety of
environmental conditions from extreme cold, earthquakes and corrosive materials.
Tru
e
Fal
se
8%
92%
1. True
2. False
1. True
2. False
A positive pressure in the distribution system is desirable to keep toxic substances out of
the system.
A positive pressure in the distribution system is desirable to keep toxic substances out of
the system.
Tru
e
Fal
se
0%
100%1. True
2. False
1. True
2. False
In general, if a water utility produces 40 to 60 pounds per square inch (psi) of water in its water mains,
individual service pressure should be sufficient to provide adequate pressure when
measured on the customer's side of the meter.
In general, if a water utility produces 40 to 60 pounds per square inch (psi) of water in its water mains,
individual service pressure should be sufficient to provide adequate pressure when
measured on the customer's side of the meter.
Tru
e
Fal
se
4%
96%1. True
2. False
1. True
2. False
The size of the water treatment plant as well as the number of specific processes it uses depend on which of the following
factors?
The size of the water treatment plant as well as the number of specific processes it uses depend on which of the following
factors?
Cost
consi
derat
ions
Dem
and fo
r wat
er b
...
Impurit
ies
in ra
w wat
er
Wat
er q
uality
purit
y ...
All
of the
above
0% 0%
100%
0%0%
a. Cost considerationsb. Demand for water by
population served and Fire protection needs
c. Impurities in raw water
d. Water quality purity standards
e. All of the above
a. Cost considerationsb. Demand for water by
population served and Fire protection needs
c. Impurities in raw water
d. Water quality purity standards
e. All of the above
Two fundamental treatment requirements for public water systems using surface water
sources are:
Two fundamental treatment requirements for public water systems using surface water
sources are:
Coag
ulatio
n and s
ed...
Lim
e so
ftenin
g and d
i...
Filt
ratio
n and a
erat
ion
Dis
infe
ctio
n and fi
ltra.
..
5%
95%
0%0%
1. Coagulation and sedimentation
2. Lime softening and disinfection
3. Filtration and aeration
4. Disinfection and filtration
1. Coagulation and sedimentation
2. Lime softening and disinfection
3. Filtration and aeration
4. Disinfection and filtration
The objectives for this week to become familiar with basic operator duties and
distribution system layouts has been met
The objectives for this week to become familiar with basic operator duties and
distribution system layouts has been met
Stro
ngly A
gree
Agre
e
Neu
tral
Dis
agre
e
Stro
ngly D
isag
...
43%38%
5%5%
10%
1. Strongly Agree
2. Agree
3. Neutral
4. Disagree
5. Strongly Disagree
1. Strongly Agree
2. Agree
3. Neutral
4. Disagree
5. Strongly Disagree