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166 Cards in this Set
- Front
- Back
Rising stem valves are used most often |
in pump stations |
|
When a bacteriological water sample comes back marked "positive" you should immediately |
resample the same location and 1 each within 5 connections upstream and downstream |
|
A connection between a safe and an unsafe water supply is |
A cross connection |
|
The number of distribution system samples that must be taken each month is based on |
the population and/or number of services |
|
The primary reason for a dry barrel fire hydrant is |
to prevent freezing |
|
Positive displacement meters are the ______ and ______type |
disc / piston |
|
The typical daily water usage in gallons per capita per day (gpcd) is about |
100 to 200 |
|
A new section of water main has series of things that must be done to it before completely backfilling and putting it into service. What is the proper order for doing them? |
1. Pressure test 2. flush 3. disinfect 4. flush 5. collect bac"t" samples |
|
Shut-off valves in residential area should be located at least every |
800 feet |
|
The average water loss )per AWWA) due to leakage in most systems is |
5 to 10% |
|
Service lines that connect the consumer to the water system usually range from |
3/4 to 1 1/2" |
|
There are several considerations to be taken into account when installing a routine bacteriological sample station. Out of the following, which would you choose? |
At a point in the distribution system representative of that area. |
|
The killing of pathogenic organisms is called |
disinfection |
|
If you went to a customer's service to turn the water off (lock-off) for non-payment, the valve you would most likely use would be the |
angle meter (curb) stop |
|
When operating valves there are two main problems that can occur (besides a stuck or broken valve). One is water hammer, the other is |
cavitation |
|
When operating a dry barrel fire hydrant it is important to operate with the valve fully open to allow |
seal off drain hole |
|
Sodium thiosulfate neutralizes ______ in water samples. |
chlorine |
|
When the flow into a reservoir is set about the same as the average demand then the reservoir is said to be |
floating |
|
Water is considered to be ____ if it's chemical, physical, and bacteriological characteristics make it satisfactory for drinking. |
potable |
|
Normally a distribution reservoir will contain _____hours of "peak period" demand. |
8 to 12 |
|
The dafe yield for a well is the amount of water that can be pumped from the aquifer over period of time that includes |
the driest year |
|
When pressure testing a new "CCCL" water main you should fill it first and wait at least |
24 hours |
|
Dissolved iron in a public water supply system may cause |
a red water problem |
|
A system that uses a sealed tank that is partially filled with air that is compressed in order to supply water pressure to a service area is called a(n). |
hydropneumatic system |
|
If a bacteriological sample cannot be analyzed within _____ it should be refrigerated. |
1 hour
|
|
"Force" is a problem with many valves used in a water system. A valve that is commonly used in larger sizes that does not suffer the effects of force is the |
butteryfly valve |
|
In waterworks terminology the word "residual" is used to describe |
The amount of chlorine or other disinfectant available for continued disinfection |
|
The USEPA sets primary and secondary standards for water. The primary standards are related to _____ and the secondary standards are related to __________. |
health / aesthetics |
|
The resistance to flow of water in a pipe is called |
friction |
|
The use of meters on consumer services has led to |
reduced usage |
|
Air release valves are installed on the |
top of water main |
|
Which of the following meters has no moving parts> |
venturi |
|
The term "water table" is used to describe |
the level to which the soil or rock voids are saturated with water |
|
If source water contains toxic agents in it that make it hazardous, it is considerd |
contaminated |
|
A venturi meter determines flow by comparing the pressure at the throat and a point just _____of the throat. |
upstream |
|
MCL stands for |
Maximum Contaminant Level |
|
Deposits in cast iron water mains are called |
tubercles |
|
A high "C" factor number indicates that a pipe |
has a smooth interior |
|
A toxic substance is always |
poisonous |
|
"Clear Wells" are used to store water from |
uncontaminated streams |
|
When collecting a water sample for bacteriological testing, you should |
flush long enough to clear the sample line |
|
Two conditions that could cause a backflow are |
backpressure and backsiphonage |
|
Positive pressure in the main is a |
consideration for water quality |
|
Any vertical wall trench ______ or deeper must be shored |
5 feet |
|
The amount of pressure pushing downward on the outside of a pipe from the earth covering it is called |
the "squeeze" |
|
The use of wells in a distribution system can decrease the needs for |
operational storage reservoirs |
|
When drawing a bacteriological sample it is important not to |
1. contaminate the bottle 2. rinse out the sodium thiosulfate 3. fill it to the very top (no air) |
|
"Thrust" is a condition that will occur at |
any change of direction in the pipe |
|
A gate valve |
is the most common isolation valve in a distribution system. |
|
The "cone of depression" is the |
area of a well's water table that is dewatered during pumping. |
|
Milky looking water is usually a result of |
air trapped in the water |
|
Consistent pressure in a distribution system reservoir |
the greater the chance for residual degradation and bacterial growth |
|
the longer water remains in a distribution reservoir |
the greater the chance for residual degradation and bacterial growth |
|
Cholera, typhoid, dysentery, and diarrhea are the most common |
water related illnesses |
|
An altitude valve is used to |
measure the feet above sea level |
|
__________ is the most common method of well construction |
Drilling |
|
The term "drawdown" is the elevation difference between the _______ and the ________. |
static water table / level during pumping |
|
When distribution valves are opened and closed rapidly |
it can cause a dangerous condition known as "water hammer" |
|
The AWWA recommends that 5/8 water meters be tested once every |
5 to 10 years |
|
The hardness of water is |
not a health related issue. |
|
The hydraulic grade line is the elevation _________ that water would rise to at a given point in a distribution system. |
"Above sea level" |
|
The carrying capacity of a water system can be improved by |
looping the water lines |
|
_________ is the minimum pressure that should be allowed in a distribution system, even during fire fighting. |
20 psi |
|
New service connections can be made on a "live" water line by making a |
"hot tap" |
|
Globe style vavles (is Cla-Valves) are mainly used for |
pressure and flow regulating |
|
Pathogenic bacteria is considered |
harmful to humans |
|
The main use of gate valves in the distribution system is for |
isolation |
|
How long does it take to get results for a Colilert bacteria test? |
24 hours |
|
Small flow meters are usually displacement meters, and large flow meters are usually |
velocity meters |
|
Drinking water standards are categorized as |
primary and secondary |
|
Concrete coated cement lined steel cylinder pipe is most commonly used for |
larger transmission lines |
|
Reservoir drains and overflows are plumbed |
with an air gap separating them from storm drains or culverts |
|
Water and sewer mains are installed |
with 10' horizontal separation and a 1' vertical separation |
|
If a trench cannot be shored for some reason, then |
the sides should be sloped |
|
After emergency repairs a water main can be chlorinated to _________ to reduce the required contact time to _________. |
300 mg/l / 15 min |
|
_________ is the preferred distribution disinfectant to aid in the control of THM's. |
Chloramines |
|
Large gate valves sometimes have a small by-pass installed around them. What is the purpose of this by-pass? |
To equalize the pressure on both sides after shutdown. |
|
Aesthetic aspects of water deal with |
taste, color, and odor. |
|
Water mains are disinfected |
after they have been installed. |
|
AWWA standards require positive displacement meters to read |
within 98.5% to 101.5% |
|
Pressure regulating stations are used to |
decrease high pressure to a steady lower pressure |
|
The type of meter most commonly used for varying assemblies are |
installed above ground at a high point in the main. |
|
As a common practice, air release and vacuum valve assemblies are |
installed above ground at a high point in the main. |
|
"Hardness" in water is generally caused by |
calcium and magnesium |
|
The "Zone of Influence" refers to the |
distance that the cone of depression affects the normal (static) water level. |
|
A positive displacement meter is usually used on a service that has |
low flows |
|
When taking a bacteria (coliform) sample it is important that the operator |
not contaminate it |
|
The AWWA has standards for accuracy requirements for new meters of various types. What are the accuracy requirements for a new positive displacement type meter at normal flow rates? |
97 - 103% |
|
The resistance to flow of water in a pipe is called |
friction |
|
In determining the purity of a water sample, it is usually tested for the presence of coliform bacteria because |
its presence indicates that the water may have been contaminated |
|
The primary purpose of distribution system storage (reservoirs) is |
to supply water at peak demands. |
|
The person in your department that is responsible for being sure that your department has a good record keeping system is |
the supervisor |
|
The maximum withdrawal rate from 150 lb chlorine cylinder is |
40 lbs / day |
|
The carry capacity of a water main can be reduced by |
tubercules |
|
The primary reason to install a dry barrel type hydrant (other than fighting fires) is |
to prevent freezing |
|
A _______ type pump must never be started against a closed discharge valve. |
centrifugal |
|
You are to dig a trench about 4.5 feet deep to install a pipe in. As you are digging you find that the soil is very loose. You are unable to slope the trench due to near-by utilities. What will help you shore this type of trench? |
Use plywood sheeting with the jacks |
|
As water meters age, they tend to |
under read |
|
When installing new packing rings in a pump you should |
stagger the joints |
|
The device installed on a pump shaft that causes the water to be (moved) forced out against the case is called the |
impeller |
|
When disinfecting a new water main, the chlorine residual must not drop below _______ for at least ________. |
25 mg/l , 24 hours |
|
If a water sample cannot be analyzed within _______ it should be refrigerated. |
1 hour |
|
The most frequently reported cause of waterborne disease in the U.S. is |
cross-connections |
|
A standard measurement of electrical power is the |
watt |
|
The pressure exerted downward on a water line from the soil covering it is known as the |
load |
|
When testing for chlorine residuals, the reagent most used is |
DPD |
|
A new section of water line has been laid. Before it is completely backfilled and put into service, several things must be done. What is the proper order for doing them? |
1. Pressure test 2. Flush 3. Disinfect 4. Flush 5. Collect bacti samples |
|
The results of a "grab" sample in a distribution system indicate |
general potability |
|
Your supervisor has instructed you to paint an existing pressure regulating station. You realize that this is a confined space and you know that you will have a problem with paint fumes. What will you do to protect yourself? |
Use auxiliary ventilation and monitor the air. |
|
Combustible gas detectors have an 'LEL" (Lower Explosive Limit) alarm setting of ________. |
10% |
|
When constructing a large well, the pump most used is a |
submersible multi-stage vertical turbine pump. |
|
Taste and odor problems are more noticeable |
when the water is warm |
|
According to the AWWA, about ________ percent of potable water supplied to a distribution is unaccounted for (due to leaks, bad meters, etc.) |
5 - 10 |
|
The difference between the amount of chlorine added and the residual detected at a given point downstream in the water distribution system is called the |
demand |
|
Rising-stem valves are usually used |
in pump stations |
|
Dry barrel hydrants have their operating valves |
in the base |
|
To find the elevation of a pipe's "invert" (inside-bottom) an operator would |
check the profile on the as-built |
|
An example of a confined space would be a(n) |
sewer manhole |
|
After the disinfection process on a new water main, bacteriological samples are drawn and the water main is put into service |
after the samples are found to be negative for coliform bacteria |
|
You have a pump that raises water to a higher elevation reservoir. This pump has a normal discharge pressure of 115 psi and a normal flow of 2,300 gpm. On a routine check, you find that the pump has a discharge pressure of 162 psi and no flow. What would you suspect is the cause? |
The tank filled up and the emergency altitude valve has shut off. |
|
When talking about pumps, the term "semi-open" refers to _______ design. |
impeller |
|
While working in a chlorine station an operator got chlorine in his eyes, he should imediately |
flush eyes with fresh water for 15 minutes |
|
A piston pump operates on the _________ principal. |
positive displacement |
|
Some of all of the forces that a pump must operate against is known as |
The total dynamic head |
|
When entering a confined space, what % oxygen level is the minimum required for self contained breathing apprentice? |
19.5% |
|
The killing of pathogenic organisms in water is called |
disinfection |
|
When drawing a sample for bacteriological examination |
leave space at the top for test medium |
|
Bacteria that are know to be disease causing are called |
Pathogens |
|
The chemical used most for disinfection of water in the U.S. is |
Chlorine |
|
Sodium hypochlorite is |
liquid chlorine |
|
Water bearing geological formation is called |
aquifer |
|
One of the biggest problems with hyrogen sulfide gas is |
de-sensitizes the nose |
|
If the speed of a positive displacement pump is varied then |
the flow with vary in direct relationship |
|
The reducer installed in a centrifugal pump is called a |
stabilizer |
|
A Ventri meter detrims flow by measuring the pressure differencial |
at the throat and a point just upstream of the throat |
|
The most important reason to use a casing the first 50' feet of a well is |
Prevent intrusion |
|
A valve that joins a customer to a water main is called a |
corporation stop |
|
The maximum suction lift from a centrifugal pump is |
34 feet |
|
To determine is a sewer line crosses under or over a water line, you would look at |
the profile view on the plans |
|
The bend or goose neck is put in a water service line to allow |
settling or movement of the soil |
|
In well terminology, the term draw down means |
the difference between the static water level and the pumping water level |
|
Compound meters are used on service connections that have |
a wide range of flows |
|
Starting a centrifugal pump against a "closed" valve helps reduce__________ and ___________. |
tuberculation / air pockets |
|
If you find a coworker unconscious at the bottom of a confined space, you should |
call for help immediately, but do not enter |
|
The most common use for a gate valve is |
as an isolation vavle |
|
Plants give off vapor to the atmosphere in a process called |
transpiration |
|
Thrust is a condition that occurs in |
any change of direction |
|
If a pump operates at a suction head of ________, mechanical seals are recommended |
60 psi |
|
Fusible plug in a chlorine cylinder is designed to melt around ___________ to release pressure in a fire. |
160 degree Fahrenheit |
|
The most commonly used pump in the water distribution system is a |
positive displacement pump |
|
All vertical wall trenches 5' or deaper |
require shoring |
|
Blow off valves are installed on |
the bottom of the water main to help drain it |
|
Velocity in a water main is usually measured |
in feet per second |
|
Distribution system pressure should not be allowed to drop below |
20 psi |
|
The major cause of undue wear in a pump is |
shift misalignment |
|
Liquefied chlorine will vaporize to gas and expand to aproximatly |
160 times its volume |
|
Potable water lines should have at least _______ of horizontal separation from the sewer main |
ten feet |
|
The C factor of a water pipe is |
the measurement of interior roughness |
|
Hardness is water is caused by presences of |
calcium and magnesium |
|
The standard current signal output used by most analog measuring devices in the water industry is |
4 to 20 MA |
|
A common a very dangerous gas found in some confined spaces is |
hydrogen sulfide |
|
The type of pipe used for large water transmission mains is |
concrete coated cement lined |
|
In residential areas, isolation valves should be located at least every |
1000 meters |
|
"MCL" stands for |
Maximum Contaminate Level |
|
The maximum amount of water that can be withdrawn from a well continually over a period of time, which includes "the dries year", is referred to as the ___________ of a well. |
"Safe Yield" |
|
The number of bacteriological samples that a water supplier must take monthly is based on |
the population and number of service connections |