CWEA GRADE 4 WASTEWATER OPERATOR 2026 TEST
BANK 400+ VERIFIED Q&A
Acid:
A substance which releases hydrogen ions
when dissolved in water. Most acids will dissolve
the common metals and will react with a base to
form a neutral salt and water. An acid is the opposite
of an alkali, has a pH rating lower than 7.0,
will turn litmus paper red, and has a sour taste.
Acidity:
The quantitative capacity of water or a
water solution to neutralize an alkali or base. It is
usually measured by titration with a standard solution
of sodium hydroxide, and is expressed in
ppm or mg/L of its calcium carbonate equivalent.
Accuracy:
The difference between the readings
of an instrument and true value of what is being
measured, expressed as a percent of full
instrument scale.
Air Gap:
A clear vertical space through the free
atmosphere, between the lowest opening of any
pipe or faucet conveying water or waste to a tank
plumbing fixture receptor or other device, and the
flood level rim of the receptacle. An air gap is used
to prevent cross connection between a water treatment
device and a possible source of wastewater,
thereby preventing a reverse flow of water from
the sewer into the water supply system. Without
an air gap, such reverse flow could occur due to
an increase in the pressure in the sewer system
or the creation of a negative pressure in the water
supply line. Local plumbing codes usually require
,the air gap to be twice the diameter of the inlet,
with a minimum width of 1.5 inches.
Alternating current (AC Power):
Electrical current
that alternates direction in cycles called hertz.
American Wire Gage (AWG): The U.S. standard
for wire size.
Alkalinity:
The quantitative capacity of water to
neutralize an acid; that is, the measure of how
much acid can be added to a liquid without causing
a significant change in pH. Alkalinity is not the
same as pH because water does not have to
be strongly basic (high pH) to have a high alkalinity.
In the water industry, alkalinity is expressed in
mg/L of equivalent calcium carbonate. There are
three kinds of alkalinity: carbonate, bicarbonate,
and hydroxide alkalinity. Total alkalinity is the sum
of all three kinds of alkalinity. Different tests are
used to determine the quantity of the different
kinds of alkalinities present in water.
Automatic Controller:
A device that measures the
value of a variable and operates to correct or limit
deviation from a selected reference. It includes
means for both measurement and control.
Automatic Control System:
Any combination of
automatic controllers connected in closed loops
with one or more processes.
Automation:
The employment of devices, which
automatically control one or more functions in an
industrial process.
Autotransformer:
,A transformer used to step
voltage up or down. The primary and secondary
windings share common turns, and it provides
no isolation.
Auxiliary Source:
A power source dedicated to providing
emergency power to a critical load when
commercial power is interrupted.
BTU:
British Thermal Unit. The energy required to
raise one pound of water one degree Fahrenheit.
One pound of water at 32°F requires the transfer
of 144 BTUs change from liquid into solid ice.
Balanced Load:
An alternating current power system
consisting of more than two current-carrying
conductors, in which these conductors all carry
the same current.
Backbone:
The major multi-channel link in a network,
from which smaller links branch.
Battery
A collection of cells, grouped together to
provide higher voltage and /or higher current than
a single cell.
Blackout:
A total loss of commercial power.
Bonding:
Deliberate connection of two or more
points to reduce any difference of potential (voltage).
Branch Circuit:
, A division of a load circuit, with
current limited by a fuse or circuit breaker.
Break-Before-Make:
Operational sequence of a
switch or relay where the existing connection is
opened prior to making the new connection.
Brownout:
A low-voltage condition lasting longer
than a few cycles. Brownouts differ from outages
only in duration.
Buck-Boost Transformer:
A small, low-voltage
transformer placed in series with the power line
to increase or reduce steady-state voltage.
Busbar:
A heavy, rigid conductor used for high
voltage feeders.
CM: Common Mode.
The term refers to electrical interference which is measurable as a ground-referenced signal. In
true common mode, a signal is common to both the current-carrying conductors.
CPU:
Abbreviation for Central Processing Unit,
which is pronounced as separate letters. The
CPU is the brain of the computer. Sometimes
referred to simply as the processor or central
processor, the CPU is the most important element
of the computer system.
Calibration:
The procedure laid down for determining,
correcting, or checking the absolute
values corresponding to the graduations on a
measuring instrument.
Capacitance:
BANK 400+ VERIFIED Q&A
Acid:
A substance which releases hydrogen ions
when dissolved in water. Most acids will dissolve
the common metals and will react with a base to
form a neutral salt and water. An acid is the opposite
of an alkali, has a pH rating lower than 7.0,
will turn litmus paper red, and has a sour taste.
Acidity:
The quantitative capacity of water or a
water solution to neutralize an alkali or base. It is
usually measured by titration with a standard solution
of sodium hydroxide, and is expressed in
ppm or mg/L of its calcium carbonate equivalent.
Accuracy:
The difference between the readings
of an instrument and true value of what is being
measured, expressed as a percent of full
instrument scale.
Air Gap:
A clear vertical space through the free
atmosphere, between the lowest opening of any
pipe or faucet conveying water or waste to a tank
plumbing fixture receptor or other device, and the
flood level rim of the receptacle. An air gap is used
to prevent cross connection between a water treatment
device and a possible source of wastewater,
thereby preventing a reverse flow of water from
the sewer into the water supply system. Without
an air gap, such reverse flow could occur due to
an increase in the pressure in the sewer system
or the creation of a negative pressure in the water
supply line. Local plumbing codes usually require
,the air gap to be twice the diameter of the inlet,
with a minimum width of 1.5 inches.
Alternating current (AC Power):
Electrical current
that alternates direction in cycles called hertz.
American Wire Gage (AWG): The U.S. standard
for wire size.
Alkalinity:
The quantitative capacity of water to
neutralize an acid; that is, the measure of how
much acid can be added to a liquid without causing
a significant change in pH. Alkalinity is not the
same as pH because water does not have to
be strongly basic (high pH) to have a high alkalinity.
In the water industry, alkalinity is expressed in
mg/L of equivalent calcium carbonate. There are
three kinds of alkalinity: carbonate, bicarbonate,
and hydroxide alkalinity. Total alkalinity is the sum
of all three kinds of alkalinity. Different tests are
used to determine the quantity of the different
kinds of alkalinities present in water.
Automatic Controller:
A device that measures the
value of a variable and operates to correct or limit
deviation from a selected reference. It includes
means for both measurement and control.
Automatic Control System:
Any combination of
automatic controllers connected in closed loops
with one or more processes.
Automation:
The employment of devices, which
automatically control one or more functions in an
industrial process.
Autotransformer:
,A transformer used to step
voltage up or down. The primary and secondary
windings share common turns, and it provides
no isolation.
Auxiliary Source:
A power source dedicated to providing
emergency power to a critical load when
commercial power is interrupted.
BTU:
British Thermal Unit. The energy required to
raise one pound of water one degree Fahrenheit.
One pound of water at 32°F requires the transfer
of 144 BTUs change from liquid into solid ice.
Balanced Load:
An alternating current power system
consisting of more than two current-carrying
conductors, in which these conductors all carry
the same current.
Backbone:
The major multi-channel link in a network,
from which smaller links branch.
Battery
A collection of cells, grouped together to
provide higher voltage and /or higher current than
a single cell.
Blackout:
A total loss of commercial power.
Bonding:
Deliberate connection of two or more
points to reduce any difference of potential (voltage).
Branch Circuit:
, A division of a load circuit, with
current limited by a fuse or circuit breaker.
Break-Before-Make:
Operational sequence of a
switch or relay where the existing connection is
opened prior to making the new connection.
Brownout:
A low-voltage condition lasting longer
than a few cycles. Brownouts differ from outages
only in duration.
Buck-Boost Transformer:
A small, low-voltage
transformer placed in series with the power line
to increase or reduce steady-state voltage.
Busbar:
A heavy, rigid conductor used for high
voltage feeders.
CM: Common Mode.
The term refers to electrical interference which is measurable as a ground-referenced signal. In
true common mode, a signal is common to both the current-carrying conductors.
CPU:
Abbreviation for Central Processing Unit,
which is pronounced as separate letters. The
CPU is the brain of the computer. Sometimes
referred to simply as the processor or central
processor, the CPU is the most important element
of the computer system.
Calibration:
The procedure laid down for determining,
correcting, or checking the absolute
values corresponding to the graduations on a
measuring instrument.
Capacitance:
