37 Multiple choice questions
Term 1 of 37
Hearing protection must be made available to all employees exposed to noise levels above
75 decibels, averaged over 10 working hours
90 decibels, averaged over 12 working hours
85 decibels, averaged over 8 working hours
70 decibels, averaged over 4 working hours
Term 2 of 37
primary treatment
process used to seperate solid matter that will settle to the bottom or float from waste
water being treated. a septic tank is an example.
methane.
screenings. this material is removed prior to pumps to prevent damage.
process used to convert dissolved or suspended materials into a form that is easier to
seperate. can be biological whereas organisms partially stabilize (oxidize) organic
matter
Term 3 of 37
Pumps are often required to bring wastewater into a treatment plant. What types of pumps are
typically used to lift influent wastewater?
Detention time.
Diaphragm pumps are used exclusively for chemical dosing in treatment plants.
Centrifugal pumps are primarily used to bring in wastewater, positive displacement
pumps are used to transport sludge.
Gear pumps are mainly used for transferring oils and lubricants in industrial settings.
,Term 4 of 37
In confined space entry, LFL stands for
Lower flammability limit
Sequencing batch reactor
Low dissolved oxygen
Upper flammability limit
Term 5 of 37
Which of the following hazardous chemicals in a hydrocarbon? Methane. Phosphoric acid.
Sodium hydroxide. Ferric chloride.
Oxygen.
Ethanol.
Propane.
Methane.
Term 6 of 37
The threshold limit value concentration for chlorine vapor is
50 ppm
25 ppm
2.0 ppm
0.5 ppm
,Term 7 of 37
secondary treatment
changing out of your work clothes and showering before leaving work
process used to convert dissolved or suspended materials into a form that is easier to
seperate. can be biological whereas organisms partially stabilize (oxidize) organic
matter
Green.
Centrifugal pumps are primarily used to bring in wastewater, positive displacement
pumps are used to transport sludge.
Term 8 of 37
If your facility stores _______ or more chlorine, you must develop a Risk Management Program in
compliance with the U.S. EPA's Chemical Accidental Release Prevention Regulations.
1140 kg (2500 lb)
500 kg (1100 lb)
1000 kg (2200 lb)
2000 kg (4400 lb)
Term 9 of 37
When mixing dry sodium hydroxide and water in an enclosed vessel or area, be sure that
the vessel or area is properly vented
the area is completely sealed off from air
the vessel is filled to the brim with water
the vessel is made of plastic to avoid corrosion
, Term 10 of 37
The time it takes for a unit volume of wastewater to pass entirely through a primary clarifier is
called
methane.
coning or "rat holing"
detention time.
green.
Term 11 of 37
Pulmonary capacity tests are required before operators can be cleared for using respiratory
equipment. These tests should be performed at a minimum of once every
2 years
5 years
6 months
3 years
Term 12 of 37
When working in confined spaces where flammable gases may be present, use only tools
made of
iron
lead
stainless steel
a non-sparking alloy