Bacteria that produces diseases are known as Ans- Pathogens
Each 100 gallons of groundwater infiltration per dary system reduces the usable capacity of the system
by... Ans- 1 person
One waterborne disease believed to be caused by a virus is... Ans- Hepatits
According to OSHA, what is the lowest safe concentration of oxygen for humans to breathe in order to
avoid oxygen deficiency? Ans- 19.5% Oxygen
What problems does hydrogen sulfide gas cause? Ans- Corrosion of sewers, structures, and equipment.
At the same pressure, the dissolved oxygen in cold water tends to be higher or lower than in warm
water Ans- higher
Which of the following is an odourus gas produced by anaerobic decomposition? Ans- H2S
The ammount of energy necessary to raise the temperature of one pound of water by one degree
ferrenheight Ans- BTU
One gallon of gasoline completely vapourized takes up how many cubic feet? Ans- 32
Sand silt and grit are mainly com[posed of Ans- inorganic matter
Oxygen required to stabalize the decomposition of organic matter in a wastewater sample by bacterial
action Ans- BOD
Wastewater in which the solids have been decomposed to relatively inert solids is called Ans- Stable
, What is the function of the bubbler control on a pump wet well Ans- Senses liquid depth in the wet well
and regulates pump operation
A dead weight tester is used to... Ans- Calibrate pressure
The effect of partially closing the discharge valve on a 3 phase induction motor driven centrifugal pump
would be to Ans- cause the motor to draw less amperage
A spacer ring in a pump packing gland to improve seal water distribution Ans- Lantern Ring
Which type of pump works on the basis of inertia or mass moving in a circular motion Ans- Centrifugal
Which type of pump works on the principle of a decrease in the overall specific weight of a confined
column of a gas-water mixture Ans- air lift
Double suction centrifugal pumps usually have the intake and discharge ports located on a horizontal
plane above, below, or even with the pump centre line Ans- Below
Leakage from a packing gland should be approximately Ans- one drop per second
Centrifugal pumps are classified according to Ans- Direction of liquid flow through the impeller
If a centrifugal pump has been running quietly and cavitation starts suddenly, this usually indicates Ans-
obstruction in the suction side
An operator finds a centrifugal pump discharging at a reduced rate. They should check for.. Ans- Clogged
or worn impeller
A positive displacement sludge pump should never be placed into operation with... Ans- the discharge
valve closed