Page 1 of 145
Mississippi Wastewater System Installer Exam
ACTUAL QUESTIONS AND ANSWERS LATEST
UPDATE THIS YEAR
Mississippi Wastewater System Installer Exam – a comprehensive practice test with 250 questions. The
format follows your requested style: summarized point-form coverage followed by MCQs with
rationales in random order.
Exam Coverage (Summarized Point Form)
• MSDH Regulation 902: Individual On-site Wastewater Disposal System standards
• Certification Requirements: 2-day training course, 80% passing score, probationary period
• Probationary Certification: Install 3 compliant systems with no deficiencies on Inspection Form
305
• Licensing & Renewal: $150 certification fee, $50K/$100K liability insurance, 3-year renewal
cycle
• Septic Tank Function: Solids separation, scum layer, sludge accumulation, anaerobic digestion
• Septic Tank Sizing: Based on daily flow (130 gallons/bedroom); residential tanks minimum 1,000
gallons
• Nonresidential Sizing: Twice the estimated daily flow
• Tank Construction Materials: Concrete (3,000 psi minimum, 2,500 psi for transport), fiberglass
(30% reinforcement), HDPE
• Tank Components: Inlet/outlet baffles, effluent filter, access risers, inspection ports
• Drainfield Function: Soil treatment and dispersal of effluent
• Drainfield Components: Distribution box, perforated PVC pipe, gravel, geotextile fabric
• Drainfield Sizing: Based on soil application rate (GPD/ft²) and daily flow
• Soil Loading Rates: Coarse sand (1.2 GPD/ft²), loamy sand (0.8 GPD/ft²), sandy loam (0.6
GPD/ft²)
• Soil Properties: Permeability, percolation rate, texture, depth to water table
• Setback Distances: Private well to drainfield (100 ft), well to tank (50 ft), property line (10 ft),
building foundation (10 ft), water line (10 ft horizontal)
• Potable Water Sources: 50 ft minimum from disinfection systems and tanks
• Alternative Systems: Mound systems (high water table), ATUs (aerobic treatment), drip
irrigation
• Maintenance Requirements: Pumping every 3-5 years, effluent filter cleaning, regular
inspections
• System Failure Signs: Ponding effluent, foul odors, lush vegetation over drainfield
• Prohibited Practices: Discharging to storm sewers, untreated wood tanks, unlicensed work
• Septage Management: Manifest required for transport, approved disposal only
• As-Built Drawings: Required after every installation
• Record Keeping: 5-year retention for installation, repair, pumping records
• Safety: H₂S gas danger, confined space entry protocols, 811 utility locating
• Site Evaluation: Soil boring, percolation testing, seasonal high water table determination
• Hydraulic Overload: Excessive water use causing drainfield failure
, Page 2 of 145
Question 1
What is the minimum passing score required on the Mississippi certified installer closed-book
examination?
A) 65%
B) 70%
C) 75%
D) 80%
Answer: D – The Mississippi certified installer examination requires a score of 80% or better to pass and
qualify for a probationary certificate .
Question 2
A homeowner with a 3-bedroom house wants to install a conventional septic system. Under Mississippi
regulations, what is the minimum effective liquid capacity of the septic tank?
A) 750 gallons
B) 900 gallons
, Page 3 of 145
C) 1,000 gallons
D) 1,200 gallons
Answer: B – Mississippi regulations require a 3-bedroom dwelling to have a minimum effective liquid
capacity of 900 gallons. The flow calculation is based on 130 gallons per bedroom, giving 390 gallons per
day .
Question 3
Which component of an onsite wastewater system is primarily responsible for separating solids from
liquids?
A) Distribution box
B) Effluent filter
C) Septic tank
D) Drainfield
Answer: C – A septic tank allows solids to settle and scum to float, separating wastewater into solid and
liquid fractions .
, Page 4 of 145
Question 4
What is the minimum setback distance from a private well to a conventional septic system drainfield in
Mississippi?
A) 50 feet
B) 75 feet
C) 100 feet
D) 150 feet
Answer: C – MSDH requires a minimum 100-foot separation from a private water well to the drainfield
to reduce groundwater contamination risks .
Question 5
After completing the training course and passing the examination, an applicant receives a probationary
certificate. What must occur before full certification is granted?
A) Complete 40 hours of additional classroom training
Mississippi Wastewater System Installer Exam
ACTUAL QUESTIONS AND ANSWERS LATEST
UPDATE THIS YEAR
Mississippi Wastewater System Installer Exam – a comprehensive practice test with 250 questions. The
format follows your requested style: summarized point-form coverage followed by MCQs with
rationales in random order.
Exam Coverage (Summarized Point Form)
• MSDH Regulation 902: Individual On-site Wastewater Disposal System standards
• Certification Requirements: 2-day training course, 80% passing score, probationary period
• Probationary Certification: Install 3 compliant systems with no deficiencies on Inspection Form
305
• Licensing & Renewal: $150 certification fee, $50K/$100K liability insurance, 3-year renewal
cycle
• Septic Tank Function: Solids separation, scum layer, sludge accumulation, anaerobic digestion
• Septic Tank Sizing: Based on daily flow (130 gallons/bedroom); residential tanks minimum 1,000
gallons
• Nonresidential Sizing: Twice the estimated daily flow
• Tank Construction Materials: Concrete (3,000 psi minimum, 2,500 psi for transport), fiberglass
(30% reinforcement), HDPE
• Tank Components: Inlet/outlet baffles, effluent filter, access risers, inspection ports
• Drainfield Function: Soil treatment and dispersal of effluent
• Drainfield Components: Distribution box, perforated PVC pipe, gravel, geotextile fabric
• Drainfield Sizing: Based on soil application rate (GPD/ft²) and daily flow
• Soil Loading Rates: Coarse sand (1.2 GPD/ft²), loamy sand (0.8 GPD/ft²), sandy loam (0.6
GPD/ft²)
• Soil Properties: Permeability, percolation rate, texture, depth to water table
• Setback Distances: Private well to drainfield (100 ft), well to tank (50 ft), property line (10 ft),
building foundation (10 ft), water line (10 ft horizontal)
• Potable Water Sources: 50 ft minimum from disinfection systems and tanks
• Alternative Systems: Mound systems (high water table), ATUs (aerobic treatment), drip
irrigation
• Maintenance Requirements: Pumping every 3-5 years, effluent filter cleaning, regular
inspections
• System Failure Signs: Ponding effluent, foul odors, lush vegetation over drainfield
• Prohibited Practices: Discharging to storm sewers, untreated wood tanks, unlicensed work
• Septage Management: Manifest required for transport, approved disposal only
• As-Built Drawings: Required after every installation
• Record Keeping: 5-year retention for installation, repair, pumping records
• Safety: H₂S gas danger, confined space entry protocols, 811 utility locating
• Site Evaluation: Soil boring, percolation testing, seasonal high water table determination
• Hydraulic Overload: Excessive water use causing drainfield failure
, Page 2 of 145
Question 1
What is the minimum passing score required on the Mississippi certified installer closed-book
examination?
A) 65%
B) 70%
C) 75%
D) 80%
Answer: D – The Mississippi certified installer examination requires a score of 80% or better to pass and
qualify for a probationary certificate .
Question 2
A homeowner with a 3-bedroom house wants to install a conventional septic system. Under Mississippi
regulations, what is the minimum effective liquid capacity of the septic tank?
A) 750 gallons
B) 900 gallons
, Page 3 of 145
C) 1,000 gallons
D) 1,200 gallons
Answer: B – Mississippi regulations require a 3-bedroom dwelling to have a minimum effective liquid
capacity of 900 gallons. The flow calculation is based on 130 gallons per bedroom, giving 390 gallons per
day .
Question 3
Which component of an onsite wastewater system is primarily responsible for separating solids from
liquids?
A) Distribution box
B) Effluent filter
C) Septic tank
D) Drainfield
Answer: C – A septic tank allows solids to settle and scum to float, separating wastewater into solid and
liquid fractions .
, Page 4 of 145
Question 4
What is the minimum setback distance from a private well to a conventional septic system drainfield in
Mississippi?
A) 50 feet
B) 75 feet
C) 100 feet
D) 150 feet
Answer: C – MSDH requires a minimum 100-foot separation from a private water well to the drainfield
to reduce groundwater contamination risks .
Question 5
After completing the training course and passing the examination, an applicant receives a probationary
certificate. What must occur before full certification is granted?
A) Complete 40 hours of additional classroom training
