Maintenance Grade 3 Exam
Questions and Answers
Question 1:
A flagger should stand:
a) On the shoulder adjacent to traffic being controlled
b) In the closed lane before stopping vehicle traffic
c) In the traffic lane
d) As stated in "A" or "B" above
Correct Answer d) As stated in "A" or "B" above
Explanation:
Flaggers should position themselves either on the shoulder next to
traffic being controlled or in the closed lane prior to stopping vehicles,
as per safety protocols.
Question 2:
Legally responsible officials are required to report Category 1 sanitary
sewer overflows:
a) Within 30 days
b) Before the end of the day
c) As soon as possible
d) Within 2 hours
,Correct Answer d) Within 2 hours
Explanation:
Regulations mandate that Category 1 sewer overflows be reported to
authorities within 2 hours to ensure rapid response and mitigation.
Question 3:
When working in confined spaces or sewers, what type of lighting
should be used?
a) Mirrors to direct sunlight or explosion-proof lighting
b) Ordinary electric lights
c) Propane, gas, or kerosene lanterns
d) Special matches
Correct Answer a) Mirrors to direct sunlight or explosion-proof lighting
Explanation:
In confined spaces, explosion-proof lighting is essential for safety, and
mirrors can help direct natural light where needed, reducing risk.
Question 4:
What can happen if water-based extinguishing agents are used on
electrical fires?
a) Nothing but extinguish the fire
b) The fumes are not harmful
c) Receive an electrical shock
d) They will corrode electrical contacts
,Correct Answer c) Receive an electrical shock
Explanation:
Water-based agents conduct electricity, increasing the risk of electrical
shock or further damage when used on electrical fires.
Question 5:
When testing a manhole for explosive gases, the first tests should be
made:
a) After removing the manhole cover
b) Before removing the manhole cover
c) At any time
d) After ventilation
Correct Answer b) Before removing the manhole cover
Explanation:
Testing for explosive gases before removing the cover ensures safety by
detecting hazards in the confined space.
Question 6:
Atmospheric hazards in manholes can include:
a) Non-explosive atmospheres
b) Non-toxic atmospheres
c) Lack of oxygen
d) Non-flammable atmospheres
, Correct Answer c) Lack of oxygen
Explanation:
Manholes may have oxygen-deficient atmospheres, which pose
suffocation risks; other hazards include toxic or flammable gases.
Question 7:
When ventilating a manhole, the air inlet should be positioned how
many feet above street level?
a) 4.0
b) 3.0
c) 2.0
d) 1.0
Correct Answer c) 2.0
Explanation:
The inlet should be approximately 2 feet above street level to ensure
effective ventilation and prevent entry of surface contaminants.
Question 8:
Which chemical is commonly used for odor control in sewer systems?
a) Calcium chloride
b) Hydrogen peroxide
c) Oxidized aluminum
d) Sodium chloride