ASPE CPD TEST PAPER 2025/2026 QUESTIONS AND
ANSWERS GUARANTEE A+
✔✔What pump capacity is thought of as ‚Äúgood design‚Äù for sump basins? - ✔✔1-
1/4 times the maximum inflow to protect against unusual flow conditions, and a duplex
sump system (each sized at 1-1/4 the max inflow) should be used for rainfall collection
to protect against flooding in the event of pump failure during a storm. Also, a source of
emergency power for storm water sump pumps is a good idea because storms and
power failures often occur at the same time. (you may use a VFD with a sump pump)
✔✔For paved and impervious areas collected in a sump, how is runoff calculated? -
✔✔A value of 1 gpm for every 24 sf can be assigned for locations where the annual rate
of rainfall is 4in/hr
✔✔How is the rate of discharge from a subsoil drainage system calculated? - ✔✔By
assigning a value of 2 gpm for each 100sf area where the soil is sandy and 1 gpm per
100sf for clay soils. Don’t forget to add the additional flow rate of clear water wastes
such as condensate drains, etc.
✔✔What should always be provided to keep harmful debris away from the pump in a
sump basin? - ✔✔A settling basin.
✔✔What kind of check valve should be used for pump discharge lines from
sump/ejector basins and why? - ✔✔A spring-loaded or weight-loaded check valve, to
keep the water from running back into a discharge basin and short cycling the pump.
✔✔What should always be installed at the discharge of each pump discharge line
(sump/ejector basin)? - ✔✔A check valve and shutoff valve (the shutoff valve on the
discharge side of the check valve so the check valve can be serviced)
✔✔What is a good rule of thumb for ejector vent sizing? - ✔✔Assign a size that is one-
half the size of the subdrain discharge pipe into the basin, or a minimum of 3 inches.
✔✔How many fixture units are equivalent to 1 gpm of pump discharge (in an ejector
system)? - ✔✔2 FUs
✔✔When an ejector vent is connected to the building venting system, how is the
addtional load on the vent pipe calculated? - ✔✔By converting the gpm discharge rate
into FU.
✔✔Ejector basins should not retain the waste discharge for a period exceeding how
long? - ✔✔12 hours
,✔✔In an ejector basin, the high and low water levels should be maintained where and
why? - ✔✔The high water level should be at least 3 inches below the invert of the
entering piping to prevent backflow and allow air circulation. The low water level should
be at least 6 inches above the bottom of the basin to ensure the suction intake of the
pump is covered by water.
✔✔What is the minimum run time on an ejector system to avoid excessive pump
cycling? - ✔✔5 minutes of pump capacity between high and low water levels
✔✔In an ejector system, how is the length of run measured and what its the minimum
size? - ✔✔From the pump outlet to the highest point, it should be at least the same size
as the pump discharge outlet. (after this point, the piping is sized as required for the
gravity house drain)
✔✔What is the recommended design velocity for flow in an ejector system? - ✔✔5 - 10
fps.
✔✔How do you determine the head of the ejector pump? - ✔✔Add the static head,
measured from the low water line in the receiver up to the highest point pumped, and
the friction head loss in the discharge piping and fittings.
✔✔In a duplex sewage ejector system, each pump is sized to satisfy what condition? -
✔✔Peak inflow.
✔✔What is used to size the ejector pump? - ✔✔Use the water supply fixture unit
method to determine flow into the receiver, then total FU is converted to GPM using a
table.
✔✔When are pneumatic-type ejectors commonly used? - ✔✔When the discharge rate
is 100 GPM or less, when large solids must be handled, where ground conditions are
such that the space below the floor is restricted, where compressed air is readily
available, and in explosion proof conditions.
✔✔What two types of lifting devices are employed for the automatic discharge of sump
or ejector basin contents? - ✔✔1) Centrifugal pumps 2) Pneumatic ejectors
✔✔A sump handles what? - ✔✔Clear waste water (sump basin not airtight, needs no
venting)
✔✔An ejector handles what? - ✔✔Sewage (ejector basin is airtight and requires
venting)
, ✔✔What is a subdrain? - ✔✔The portion of a drainage system that cannot drain by
gravity into the building sewer. (these wastes flow into a receiving tank or sump, which
is pumped into the gravity drainage system)
✔✔On a pump curve, pump head (ft) is proportional to what? - ✔✔The ratio of the GPM
squared
✔✔The head in a typical system is comprised of what three components? (pump
chapter) - ✔✔1) Static head 2) Required pressure at each piece of equipment or fixture
in the critical branch (total) 3) Friction head losses in the pipe and fittings (these vary
with capacity)
✔✔A centrifugal pump always operates at what condition? - ✔✔The intersection of its
head/capacity curve and the system head/capacity curve.
✔✔When selecting a centrifugal pump, in addition to determining the required head at
the design capacity, it is very important to also check what? - ✔✔The system
head/capacity curve to avoid possible future problems. The pump must be able of
satisfying minimum and maximum requirements in addition to the design requirements.
✔✔For parallel operation, the pump heads must be equal, but what may vary? -
✔✔Pump capacities.
✔✔For series operation, the pump capacities must be equal, but what may have
different values? - ✔✔Pump heads.
✔✔For multiple pump system proper operation, all pumps should have what type of
curve? - ✔✔Continuously rising characteristic.
✔✔For parallel operation of two or more pumps, the combined performance curve is
obtained by adding what? - ✔✔The capacities horizontally at the same heads. (100
GPM at 30‘ + 100 GPM at 30‘ = 200 GPM at 30’)
✔✔For series operation of two or more pumps, the combined performance curve is
obtained by adding what? - ✔✔The heads vertically at the same capacities. (100 GPM
at 30‘ + 100 GPM at 30‘ = 100 GPM at 60’)
✔✔When is a good time to use two or more pumps in parallel? - ✔✔When the system
demand varies greatly.
✔✔What is the benefit of operating pumps in parallel? - ✔✔To obtain greater capacities.
ANSWERS GUARANTEE A+
✔✔What pump capacity is thought of as ‚Äúgood design‚Äù for sump basins? - ✔✔1-
1/4 times the maximum inflow to protect against unusual flow conditions, and a duplex
sump system (each sized at 1-1/4 the max inflow) should be used for rainfall collection
to protect against flooding in the event of pump failure during a storm. Also, a source of
emergency power for storm water sump pumps is a good idea because storms and
power failures often occur at the same time. (you may use a VFD with a sump pump)
✔✔For paved and impervious areas collected in a sump, how is runoff calculated? -
✔✔A value of 1 gpm for every 24 sf can be assigned for locations where the annual rate
of rainfall is 4in/hr
✔✔How is the rate of discharge from a subsoil drainage system calculated? - ✔✔By
assigning a value of 2 gpm for each 100sf area where the soil is sandy and 1 gpm per
100sf for clay soils. Don’t forget to add the additional flow rate of clear water wastes
such as condensate drains, etc.
✔✔What should always be provided to keep harmful debris away from the pump in a
sump basin? - ✔✔A settling basin.
✔✔What kind of check valve should be used for pump discharge lines from
sump/ejector basins and why? - ✔✔A spring-loaded or weight-loaded check valve, to
keep the water from running back into a discharge basin and short cycling the pump.
✔✔What should always be installed at the discharge of each pump discharge line
(sump/ejector basin)? - ✔✔A check valve and shutoff valve (the shutoff valve on the
discharge side of the check valve so the check valve can be serviced)
✔✔What is a good rule of thumb for ejector vent sizing? - ✔✔Assign a size that is one-
half the size of the subdrain discharge pipe into the basin, or a minimum of 3 inches.
✔✔How many fixture units are equivalent to 1 gpm of pump discharge (in an ejector
system)? - ✔✔2 FUs
✔✔When an ejector vent is connected to the building venting system, how is the
addtional load on the vent pipe calculated? - ✔✔By converting the gpm discharge rate
into FU.
✔✔Ejector basins should not retain the waste discharge for a period exceeding how
long? - ✔✔12 hours
,✔✔In an ejector basin, the high and low water levels should be maintained where and
why? - ✔✔The high water level should be at least 3 inches below the invert of the
entering piping to prevent backflow and allow air circulation. The low water level should
be at least 6 inches above the bottom of the basin to ensure the suction intake of the
pump is covered by water.
✔✔What is the minimum run time on an ejector system to avoid excessive pump
cycling? - ✔✔5 minutes of pump capacity between high and low water levels
✔✔In an ejector system, how is the length of run measured and what its the minimum
size? - ✔✔From the pump outlet to the highest point, it should be at least the same size
as the pump discharge outlet. (after this point, the piping is sized as required for the
gravity house drain)
✔✔What is the recommended design velocity for flow in an ejector system? - ✔✔5 - 10
fps.
✔✔How do you determine the head of the ejector pump? - ✔✔Add the static head,
measured from the low water line in the receiver up to the highest point pumped, and
the friction head loss in the discharge piping and fittings.
✔✔In a duplex sewage ejector system, each pump is sized to satisfy what condition? -
✔✔Peak inflow.
✔✔What is used to size the ejector pump? - ✔✔Use the water supply fixture unit
method to determine flow into the receiver, then total FU is converted to GPM using a
table.
✔✔When are pneumatic-type ejectors commonly used? - ✔✔When the discharge rate
is 100 GPM or less, when large solids must be handled, where ground conditions are
such that the space below the floor is restricted, where compressed air is readily
available, and in explosion proof conditions.
✔✔What two types of lifting devices are employed for the automatic discharge of sump
or ejector basin contents? - ✔✔1) Centrifugal pumps 2) Pneumatic ejectors
✔✔A sump handles what? - ✔✔Clear waste water (sump basin not airtight, needs no
venting)
✔✔An ejector handles what? - ✔✔Sewage (ejector basin is airtight and requires
venting)
, ✔✔What is a subdrain? - ✔✔The portion of a drainage system that cannot drain by
gravity into the building sewer. (these wastes flow into a receiving tank or sump, which
is pumped into the gravity drainage system)
✔✔On a pump curve, pump head (ft) is proportional to what? - ✔✔The ratio of the GPM
squared
✔✔The head in a typical system is comprised of what three components? (pump
chapter) - ✔✔1) Static head 2) Required pressure at each piece of equipment or fixture
in the critical branch (total) 3) Friction head losses in the pipe and fittings (these vary
with capacity)
✔✔A centrifugal pump always operates at what condition? - ✔✔The intersection of its
head/capacity curve and the system head/capacity curve.
✔✔When selecting a centrifugal pump, in addition to determining the required head at
the design capacity, it is very important to also check what? - ✔✔The system
head/capacity curve to avoid possible future problems. The pump must be able of
satisfying minimum and maximum requirements in addition to the design requirements.
✔✔For parallel operation, the pump heads must be equal, but what may vary? -
✔✔Pump capacities.
✔✔For series operation, the pump capacities must be equal, but what may have
different values? - ✔✔Pump heads.
✔✔For multiple pump system proper operation, all pumps should have what type of
curve? - ✔✔Continuously rising characteristic.
✔✔For parallel operation of two or more pumps, the combined performance curve is
obtained by adding what? - ✔✔The capacities horizontally at the same heads. (100
GPM at 30‘ + 100 GPM at 30‘ = 200 GPM at 30’)
✔✔For series operation of two or more pumps, the combined performance curve is
obtained by adding what? - ✔✔The heads vertically at the same capacities. (100 GPM
at 30‘ + 100 GPM at 30‘ = 100 GPM at 60’)
✔✔When is a good time to use two or more pumps in parallel? - ✔✔When the system
demand varies greatly.
✔✔What is the benefit of operating pumps in parallel? - ✔✔To obtain greater capacities.
