TANKS & SEWERS EXAMINATION
COMPLETE QUESTIONS AND DETAILED
SOLUTIONS LATEST UPDATE THIS YEAR
JUST RELEASED
The New Mexico (MS-3) Cesspools, Septic Tanks & Sewers
examination is designed to assess the competency of
contractors and tradespersons involved in the installation,
repair, maintenance, inspection, and regulatory
compliance of wastewater disposal systems. Candidates are
expected to demonstrate knowledge of septic system
design principles, soil evaluation, excavation safety, sewer
installation, piping materials, drainage requirements,
environmental protection standards, wastewater
treatment processes, construction practices, permit
requirements, and occupational safety. Questions are
commonly scenario-based and focus on practical field
situations encountered during residential and commercial
onsite wastewater projects.
, Exam Coverage
Septic tank sizing and installation requirements
Cesspool construction and abandonment procedures
Sewer line installation methods
Soil classifications and percolation testing
Wastewater flow calculations
Drainfield design and layout
Pipe materials, fittings, and connections
Excavation and trench safety
Inspection and testing procedures
Pump systems and lift stations
Effluent treatment principles
Maintenance and troubleshooting
Environmental and groundwater protection
Permit and regulatory compliance
Construction mathematics
Safety standards and hazard recognition
1.
,A contractor installs a septic tank serving a four-bedroom
residence. Which factor most directly determines the
minimum required tank capacity?
A. Number of windows in the residence
B. Daily wastewater flow estimate
C. Roof drainage area
D. Distance to nearest roadway
Answer: B
Rationale: Septic tank sizing is primarily based on
estimated daily wastewater generation to provide
adequate detention time and treatment capacity.
2.
During excavation for a sewer trench deeper than five feet,
workers enter the excavation without protective systems.
What is the greatest immediate hazard?
A. Pipe corrosion
B. Soil settlement
C. Trench collapse and burial
D. Wastewater backup
Answer: C
Rationale: Deep trenches present serious cave-in risks
capable of causing severe injury or death.
, 3.
A percolation test reveals extremely slow water absorption
rates. What design adjustment is most likely necessary?
A. Smaller drainfield area
B. Larger drainfield area
C. Reduced septic tank volume
D. Elimination of inspection ports
Answer: B
Rationale: Slowly permeable soils require larger absorption
areas to disperse wastewater effectively.
4.
Which component primarily separates settleable solids
from wastewater before effluent enters a drainfield?
A. Distribution box
B. Septic tank
C. Vent stack
D. Cleanout
Answer: B
Rationale: Septic tanks provide sedimentation and
flotation processes that remove solids and scum.