New Hampshire Septic System Installer Exam Practice - Original Questions & Answers - Comprehensive Final Assessment -
Detailed Rationales - Complete Exam
New Hampshire DES Subsurface Systems | Env-Wq 1000 | Septic System Installer License | Different Title 5
TABLE OF CONTENTS
1. I. NH DES Rules Env-Wq 1000 Overview - Subsurface Systems Bureau, Installer License Requirements Exam Experience CE
2. II. Soil Evaluation - Test Pit Requirements Depth 5 Feet Minimum, Seasonal High Water Table SHWT Redoximorphic Mottling Gray Colors
Observed Water March-June Monitor Wells
3. III. Separation Distances - 24 Inches Minimum Bottom of EDA to SHWT, 48 Inches to Ledge Refusal, Perc Test Depth Proposed System
Presoak
4. IV. Percolation Test - Soil Absorption Rate Minutes Per Inch, Test at Proposed Depth, Presoak, Sizing EDA Based on Rate
5. V. Design Flow - Bedrooms Flow 4 Bedroom 600 GPD, Septic Tank Sizing 4BR 1000 Gal 5BR 1250 Gal 6BR 1500 Gal, Garbage Disposal
Increase 20 Percent or 50 Percent Larger Tank
6. VI. Setbacks Env-Wq 1008 - Septic Tank 75 Feet Private Well Leach Field 75 Feet Private Well 100 Feet Public Well, Surface Water 75
Feet Wetlands 75 Feet, Property Line 10 Feet Building 10 Feet
7. VII. Effluent Disposal Area EDA - Trenches Beds Chambers, Trench Size 12 Inches Minimum Wide 18-36 Wide Depth 12-36 Aggregate 6
Below 2 Above Pipe, D-box Level 5 Ports Max Compacted Soil Accessible
8. VIII. Mound Systems - Required When Separation Cannot Be Met In-Ground, 24 Inches Separation Maintained in Fill, 48 Inches to Ledge,
ASTM C33 Sand Fill Observation Ports Licensed Installer
9. IX. Pressure Distribution - Required Mound Large Systems Perc greater than 30 mpi, Pump Chamber Pressure Manifold Small Holes Even
Distribution
10. X. Installation Standards - Pipe Slope 1/4 Inch Per Foot Tank to D-box 2 Percent Gravity Flow, Watertight Tanks, Floodplain Requirements
No Increase Flood Level
11. XI. Soil Types - Suitable Loamy Sand Sandy Loam, Unsuitable Clay Perc greater than 60 mpi High Water Table Ledge Within 24/48 Inches
Requires Alternative
12. XII. Pumping Maintenance - Every 3-5 Years Inspection Pump When Sludge plus Scum 1/3 Tank Depth
13. XIII. Replacement Systems - Must Meet Current Env-Wq 1000 Standards New Permit Test Pits Perc Required No Grandfather
14. XIV. Holding Tanks - Last Resort No Feasible EDA DES Waiver Frequent Pumping Alarm No New Construction Generally Hardship
15. XV. Practice Questions - Original Questions Each Asked Like Real NH Septic Installer Exam - Hinted Complete Exam
16. XVI. Answer Key with Detailed Rationales - Complete Exam
,NEW HAMPSHIRE SEPTIC SYSTEM INSTALLER EXAM - PRACTICE QUESTIONS - EACH QUESTION ASKED LIKE REAL
EXAM
Based on NH DES Env-Wq 1000 Subsurface Systems Rules, Setbacks, Test Pit, Perc Test, Design Flow, Mound Systems. High Yield.
1. What is required for a mound system in New Hampshire?
A. Only sand
B. No observation
C. No special requirements
D. Required when separation to water table or ledge cannot be met with in-ground - 24 inches separation maintained in mound fill, 48 inches to ledge,
observation ports, specific sand fill ASTM C33, licensed installer
Answer: D
Rationale: Mound required when separation cannot be met in-ground, maintain 24 inches to water table in fill, 48 inches to ledge, ASTM C33 sand,
observation ports, licensed installer.
2. What license is required to install septic in NH?
A. Only plumbing license
B. No license
C. NH DES Septic System Installer license - requires exam, experience, continuing education - Subsurface Systems
D. No exam
Answer: C
Rationale: NH requires DES Septic System Installer license exam experience CE.
3. What is the purpose of a percolation test in NH septic design?
A. To find water table
B. To determine tank size
C. To find ledge
D. To determine soil absorption rate - minutes per inch - test at depth of proposed system, presoak, measure rate, determines sizing of leach field per
Env-Wq
Answer: D
Rationale: Perc test determines soil absorption rate minutes per inch at proposed depth, presoak required, sizing leach field based on rate.
4. A 4-bedroom home in NH with 2.5 gpm well produces 600 gpd design flow. What size septic tank is required per NH rules?
A. 500 gallons
B. 1000 gallons minimum for up to 4 bedrooms per Env-Wq - 4 bedrooms 1000 gal tank, 5 bedrooms 1250 gal, 6 bedrooms 1500 gal - 600 gpd 4BR
needs 1000 gal
C. 1500 gallons
D. 750 gallons
Answer: B
Rationale: NH septic tank sizing: up to 4 bedrooms 1000 gal minimum, 5BR 1250 gal, 6BR 1500 gal per Env-Wq 1000.
5. How to determine seasonal high water table in NH test pit?
A. Only dig
B. No method
C. Only guess
D. Observe soil redoximorphic features mottling, gray colors, observed water level during wet season March-June, monitor wells
Answer: D
Rationale: SHWT determined by redoximorphic mottling gray colors observed water wet season March-June monitor wells.
6. How often must a septic tank be pumped in NH per DES recommendation?
A. Every year
B. Never
C. Every 3-5 years depending on use, tank size, garbage disposal - inspection every 3-5 years, pump when sludge+scum 1/3 tank depth
D. Every 10 years
Answer: C
Rationale: DES recommends pump every 3-5 years, inspect, pump when sludge+scum 1/3 depth.
7. What is a holding tank and when allowed in NH?
A. Allowed only as last resort no other feasible EDA, requires DES waiver, frequent pumping, alarm, no new construction generally - existing lots hardship
B. No restrictions
C. Always for new homes
D. Always allowed
Answer: A
Rationale: Holding tank last resort no feasible EDA DES waiver frequent pumping alarm no new construction generally hardship.
8. What license is required to install septic in NH?
A. NH DES Septic System Installer license - requires exam, experience, continuing education - Subsurface Systems
B. No license
C. Only plumbing license
,D. No exam
Answer: A
Rationale: NH requires DES Septic System Installer license exam experience CE.
9. What is the role of a D-box (distribution box) in NH septic?
A. Only stores
B. No role
C. Only collects
D. Distributes effluent evenly to laterals - must be level, 5 ports max, set on compacted soil, accessible
Answer: D
Rationale: D-box distributes effluent evenly to laterals level 5 ports max compacted soil accessible.
10. What is required for septic system in floodplain in NH?
A. Can install anywhere
B. Must meet additional DES requirements - floodplain construction, no increase flood level, watertight tanks, check local floodplain ordinance Env-Wq
C. No requirements
D. Only tank
Answer: B
Rationale: Floodplain septic must meet DES floodplain requirements watertight tanks no increase flood level local ordinance.
11. What is the minimum size for a leach field trench in NH?
A. No minimum
B. 48 inches
C. Typically 12 inches wide minimum, 18-36 inches wide trenches, depth 12-36 inches, aggregate 6 inches below 2 inches above pipe
D. 6 inches wide
Answer: C
Rationale: Trench typically 12 inches minimum wide 18-36 wide depth 12-36 aggregate 6 below 2 above pipe per NH.
12. What is the purpose of a percolation test in NH septic design?
A. To determine soil absorption rate - minutes per inch - test at depth of proposed system, presoak, measure rate, determines sizing of leach field per
Env-Wq
B. To find water table
C. To find ledge
D. To determine tank size
Answer: A
Rationale: Perc test determines soil absorption rate minutes per inch at proposed depth, presoak required, sizing leach field based on rate.
13. What is the minimum size for a leach field trench in NH?
A. No minimum
B. Typically 12 inches wide minimum, 18-36 inches wide trenches, depth 12-36 inches, aggregate 6 inches below 2 inches above pipe
C. 48 inches
D. 6 inches wide
Answer: B
Rationale: Trench typically 12 inches minimum wide 18-36 wide depth 12-36 aggregate 6 below 2 above pipe per NH.
14. A homeowner in New Hampshire wants to install a septic system on a lot with high seasonal high water table at 12 inches. What is the
minimum separation distance required between bottom of leach field and seasonal high water table per NH DES rules?
A. 6 inches
B. 24 inches minimum separation - bottom of bed must be 24 inches above seasonal high water table per Env-Wq 1000 - if 12 inches water table need fill
or mound
C. 0 inches
D. 12 inches
Answer: B
Rationale: NH Env-Wq 1000 requires 24 inches separation between bottom of leach field and seasonal high water table. If water table 12 inches need
mound system or fill.
15. What license is required to install septic in NH?
A. Only plumbing license
B. NH DES Septic System Installer license - requires exam, experience, continuing education - Subsurface Systems
C. No license
D. No exam
Answer: B
Rationale: NH requires DES Septic System Installer license exam experience CE.
16. A septic installer in NH encounters a 12-inch diameter pipe from tank to D-box. What slope is required?
A. 1 inch per foot
B. No slope
C. Flat
D. 1/4 inch per foot minimum from tank to D-box - 2% slope - 1/4 inch per foot - ensure gravity flow
Answer: D
, Rationale: Pipe from tank to D-box requires 1/4 inch per foot minimum slope gravity flow.
17. What is a holding tank and when allowed in NH?
A. Always for new homes
B. No restrictions
C. Allowed only as last resort no other feasible EDA, requires DES waiver, frequent pumping, alarm, no new construction generally - existing lots hardship
D. Always allowed
Answer: C
Rationale: Holding tank last resort no feasible EDA DES waiver frequent pumping alarm no new construction generally hardship.
18. What license is required to install septic in NH?
A. No exam
B. Only plumbing license
C. NH DES Septic System Installer license - requires exam, experience, continuing education - Subsurface Systems
D. No license
Answer: C
Rationale: NH requires DES Septic System Installer license exam experience CE.
19. What is required for a replacement system in NH?
A. Grandfathered
B. No permit
C. Must meet current Env-Wq 1000 standards - new permit required - test pits perc tests required even if existing system - no grandfather for replacement
D. Same as new
Answer: C
Rationale: Replacement system must meet current standards new permit test pits perc required no grandfather.
20. How to determine seasonal high water table in NH test pit?
A. No method
B. Only guess
C. Only dig
D. Observe soil redoximorphic features mottling, gray colors, observed water level during wet season March-June, monitor wells
Answer: D
Rationale: SHWT determined by redoximorphic mottling gray colors observed water wet season March-June monitor wells.
21. What is a holding tank and when allowed in NH?
A. No restrictions
B. Always for new homes
C. Always allowed
D. Allowed only as last resort no other feasible EDA, requires DES waiver, frequent pumping, alarm, no new construction generally - existing lots hardship
Answer: D
Rationale: Holding tank last resort no feasible EDA DES waiver frequent pumping alarm no new construction generally hardship.
22. What soil type is unsuitable for standard leach field in NH?
A. Loamy sand
B. Sandy loam
C. Clay with perc >60 min/inch - rate >60 mpi unsuitable - also high water table ledge within 24/48 inches - requires alternative system
D. Sand
Answer: C
Rationale: Clay perc >60 min/inch unsuitable for standard field requires alternative system.
23. What license is required to install septic in NH?
A. No exam
B. Only plumbing license
C. NH DES Septic System Installer license - requires exam, experience, continuing education - Subsurface Systems
D. No license
Answer: C
Rationale: NH requires DES Septic System Installer license exam experience CE.
24. What is the purpose of a percolation test in NH septic design?
A. To find ledge
B. To determine tank size
C. To find water table
D. To determine soil absorption rate - minutes per inch - test at depth of proposed system, presoak, measure rate, determines sizing of leach field per
Env-Wq
Answer: D
Rationale: Perc test determines soil absorption rate minutes per inch at proposed depth, presoak required, sizing leach field based on rate.
25. A 4-bedroom home in NH with 2.5 gpm well produces 600 gpd design flow. What size septic tank is required per NH rules?
A. 750 gallons
B. 500 gallons
Detailed Rationales - Complete Exam
New Hampshire DES Subsurface Systems | Env-Wq 1000 | Septic System Installer License | Different Title 5
TABLE OF CONTENTS
1. I. NH DES Rules Env-Wq 1000 Overview - Subsurface Systems Bureau, Installer License Requirements Exam Experience CE
2. II. Soil Evaluation - Test Pit Requirements Depth 5 Feet Minimum, Seasonal High Water Table SHWT Redoximorphic Mottling Gray Colors
Observed Water March-June Monitor Wells
3. III. Separation Distances - 24 Inches Minimum Bottom of EDA to SHWT, 48 Inches to Ledge Refusal, Perc Test Depth Proposed System
Presoak
4. IV. Percolation Test - Soil Absorption Rate Minutes Per Inch, Test at Proposed Depth, Presoak, Sizing EDA Based on Rate
5. V. Design Flow - Bedrooms Flow 4 Bedroom 600 GPD, Septic Tank Sizing 4BR 1000 Gal 5BR 1250 Gal 6BR 1500 Gal, Garbage Disposal
Increase 20 Percent or 50 Percent Larger Tank
6. VI. Setbacks Env-Wq 1008 - Septic Tank 75 Feet Private Well Leach Field 75 Feet Private Well 100 Feet Public Well, Surface Water 75
Feet Wetlands 75 Feet, Property Line 10 Feet Building 10 Feet
7. VII. Effluent Disposal Area EDA - Trenches Beds Chambers, Trench Size 12 Inches Minimum Wide 18-36 Wide Depth 12-36 Aggregate 6
Below 2 Above Pipe, D-box Level 5 Ports Max Compacted Soil Accessible
8. VIII. Mound Systems - Required When Separation Cannot Be Met In-Ground, 24 Inches Separation Maintained in Fill, 48 Inches to Ledge,
ASTM C33 Sand Fill Observation Ports Licensed Installer
9. IX. Pressure Distribution - Required Mound Large Systems Perc greater than 30 mpi, Pump Chamber Pressure Manifold Small Holes Even
Distribution
10. X. Installation Standards - Pipe Slope 1/4 Inch Per Foot Tank to D-box 2 Percent Gravity Flow, Watertight Tanks, Floodplain Requirements
No Increase Flood Level
11. XI. Soil Types - Suitable Loamy Sand Sandy Loam, Unsuitable Clay Perc greater than 60 mpi High Water Table Ledge Within 24/48 Inches
Requires Alternative
12. XII. Pumping Maintenance - Every 3-5 Years Inspection Pump When Sludge plus Scum 1/3 Tank Depth
13. XIII. Replacement Systems - Must Meet Current Env-Wq 1000 Standards New Permit Test Pits Perc Required No Grandfather
14. XIV. Holding Tanks - Last Resort No Feasible EDA DES Waiver Frequent Pumping Alarm No New Construction Generally Hardship
15. XV. Practice Questions - Original Questions Each Asked Like Real NH Septic Installer Exam - Hinted Complete Exam
16. XVI. Answer Key with Detailed Rationales - Complete Exam
,NEW HAMPSHIRE SEPTIC SYSTEM INSTALLER EXAM - PRACTICE QUESTIONS - EACH QUESTION ASKED LIKE REAL
EXAM
Based on NH DES Env-Wq 1000 Subsurface Systems Rules, Setbacks, Test Pit, Perc Test, Design Flow, Mound Systems. High Yield.
1. What is required for a mound system in New Hampshire?
A. Only sand
B. No observation
C. No special requirements
D. Required when separation to water table or ledge cannot be met with in-ground - 24 inches separation maintained in mound fill, 48 inches to ledge,
observation ports, specific sand fill ASTM C33, licensed installer
Answer: D
Rationale: Mound required when separation cannot be met in-ground, maintain 24 inches to water table in fill, 48 inches to ledge, ASTM C33 sand,
observation ports, licensed installer.
2. What license is required to install septic in NH?
A. Only plumbing license
B. No license
C. NH DES Septic System Installer license - requires exam, experience, continuing education - Subsurface Systems
D. No exam
Answer: C
Rationale: NH requires DES Septic System Installer license exam experience CE.
3. What is the purpose of a percolation test in NH septic design?
A. To find water table
B. To determine tank size
C. To find ledge
D. To determine soil absorption rate - minutes per inch - test at depth of proposed system, presoak, measure rate, determines sizing of leach field per
Env-Wq
Answer: D
Rationale: Perc test determines soil absorption rate minutes per inch at proposed depth, presoak required, sizing leach field based on rate.
4. A 4-bedroom home in NH with 2.5 gpm well produces 600 gpd design flow. What size septic tank is required per NH rules?
A. 500 gallons
B. 1000 gallons minimum for up to 4 bedrooms per Env-Wq - 4 bedrooms 1000 gal tank, 5 bedrooms 1250 gal, 6 bedrooms 1500 gal - 600 gpd 4BR
needs 1000 gal
C. 1500 gallons
D. 750 gallons
Answer: B
Rationale: NH septic tank sizing: up to 4 bedrooms 1000 gal minimum, 5BR 1250 gal, 6BR 1500 gal per Env-Wq 1000.
5. How to determine seasonal high water table in NH test pit?
A. Only dig
B. No method
C. Only guess
D. Observe soil redoximorphic features mottling, gray colors, observed water level during wet season March-June, monitor wells
Answer: D
Rationale: SHWT determined by redoximorphic mottling gray colors observed water wet season March-June monitor wells.
6. How often must a septic tank be pumped in NH per DES recommendation?
A. Every year
B. Never
C. Every 3-5 years depending on use, tank size, garbage disposal - inspection every 3-5 years, pump when sludge+scum 1/3 tank depth
D. Every 10 years
Answer: C
Rationale: DES recommends pump every 3-5 years, inspect, pump when sludge+scum 1/3 depth.
7. What is a holding tank and when allowed in NH?
A. Allowed only as last resort no other feasible EDA, requires DES waiver, frequent pumping, alarm, no new construction generally - existing lots hardship
B. No restrictions
C. Always for new homes
D. Always allowed
Answer: A
Rationale: Holding tank last resort no feasible EDA DES waiver frequent pumping alarm no new construction generally hardship.
8. What license is required to install septic in NH?
A. NH DES Septic System Installer license - requires exam, experience, continuing education - Subsurface Systems
B. No license
C. Only plumbing license
,D. No exam
Answer: A
Rationale: NH requires DES Septic System Installer license exam experience CE.
9. What is the role of a D-box (distribution box) in NH septic?
A. Only stores
B. No role
C. Only collects
D. Distributes effluent evenly to laterals - must be level, 5 ports max, set on compacted soil, accessible
Answer: D
Rationale: D-box distributes effluent evenly to laterals level 5 ports max compacted soil accessible.
10. What is required for septic system in floodplain in NH?
A. Can install anywhere
B. Must meet additional DES requirements - floodplain construction, no increase flood level, watertight tanks, check local floodplain ordinance Env-Wq
C. No requirements
D. Only tank
Answer: B
Rationale: Floodplain septic must meet DES floodplain requirements watertight tanks no increase flood level local ordinance.
11. What is the minimum size for a leach field trench in NH?
A. No minimum
B. 48 inches
C. Typically 12 inches wide minimum, 18-36 inches wide trenches, depth 12-36 inches, aggregate 6 inches below 2 inches above pipe
D. 6 inches wide
Answer: C
Rationale: Trench typically 12 inches minimum wide 18-36 wide depth 12-36 aggregate 6 below 2 above pipe per NH.
12. What is the purpose of a percolation test in NH septic design?
A. To determine soil absorption rate - minutes per inch - test at depth of proposed system, presoak, measure rate, determines sizing of leach field per
Env-Wq
B. To find water table
C. To find ledge
D. To determine tank size
Answer: A
Rationale: Perc test determines soil absorption rate minutes per inch at proposed depth, presoak required, sizing leach field based on rate.
13. What is the minimum size for a leach field trench in NH?
A. No minimum
B. Typically 12 inches wide minimum, 18-36 inches wide trenches, depth 12-36 inches, aggregate 6 inches below 2 inches above pipe
C. 48 inches
D. 6 inches wide
Answer: B
Rationale: Trench typically 12 inches minimum wide 18-36 wide depth 12-36 aggregate 6 below 2 above pipe per NH.
14. A homeowner in New Hampshire wants to install a septic system on a lot with high seasonal high water table at 12 inches. What is the
minimum separation distance required between bottom of leach field and seasonal high water table per NH DES rules?
A. 6 inches
B. 24 inches minimum separation - bottom of bed must be 24 inches above seasonal high water table per Env-Wq 1000 - if 12 inches water table need fill
or mound
C. 0 inches
D. 12 inches
Answer: B
Rationale: NH Env-Wq 1000 requires 24 inches separation between bottom of leach field and seasonal high water table. If water table 12 inches need
mound system or fill.
15. What license is required to install septic in NH?
A. Only plumbing license
B. NH DES Septic System Installer license - requires exam, experience, continuing education - Subsurface Systems
C. No license
D. No exam
Answer: B
Rationale: NH requires DES Septic System Installer license exam experience CE.
16. A septic installer in NH encounters a 12-inch diameter pipe from tank to D-box. What slope is required?
A. 1 inch per foot
B. No slope
C. Flat
D. 1/4 inch per foot minimum from tank to D-box - 2% slope - 1/4 inch per foot - ensure gravity flow
Answer: D
, Rationale: Pipe from tank to D-box requires 1/4 inch per foot minimum slope gravity flow.
17. What is a holding tank and when allowed in NH?
A. Always for new homes
B. No restrictions
C. Allowed only as last resort no other feasible EDA, requires DES waiver, frequent pumping, alarm, no new construction generally - existing lots hardship
D. Always allowed
Answer: C
Rationale: Holding tank last resort no feasible EDA DES waiver frequent pumping alarm no new construction generally hardship.
18. What license is required to install septic in NH?
A. No exam
B. Only plumbing license
C. NH DES Septic System Installer license - requires exam, experience, continuing education - Subsurface Systems
D. No license
Answer: C
Rationale: NH requires DES Septic System Installer license exam experience CE.
19. What is required for a replacement system in NH?
A. Grandfathered
B. No permit
C. Must meet current Env-Wq 1000 standards - new permit required - test pits perc tests required even if existing system - no grandfather for replacement
D. Same as new
Answer: C
Rationale: Replacement system must meet current standards new permit test pits perc required no grandfather.
20. How to determine seasonal high water table in NH test pit?
A. No method
B. Only guess
C. Only dig
D. Observe soil redoximorphic features mottling, gray colors, observed water level during wet season March-June, monitor wells
Answer: D
Rationale: SHWT determined by redoximorphic mottling gray colors observed water wet season March-June monitor wells.
21. What is a holding tank and when allowed in NH?
A. No restrictions
B. Always for new homes
C. Always allowed
D. Allowed only as last resort no other feasible EDA, requires DES waiver, frequent pumping, alarm, no new construction generally - existing lots hardship
Answer: D
Rationale: Holding tank last resort no feasible EDA DES waiver frequent pumping alarm no new construction generally hardship.
22. What soil type is unsuitable for standard leach field in NH?
A. Loamy sand
B. Sandy loam
C. Clay with perc >60 min/inch - rate >60 mpi unsuitable - also high water table ledge within 24/48 inches - requires alternative system
D. Sand
Answer: C
Rationale: Clay perc >60 min/inch unsuitable for standard field requires alternative system.
23. What license is required to install septic in NH?
A. No exam
B. Only plumbing license
C. NH DES Septic System Installer license - requires exam, experience, continuing education - Subsurface Systems
D. No license
Answer: C
Rationale: NH requires DES Septic System Installer license exam experience CE.
24. What is the purpose of a percolation test in NH septic design?
A. To find ledge
B. To determine tank size
C. To find water table
D. To determine soil absorption rate - minutes per inch - test at depth of proposed system, presoak, measure rate, determines sizing of leach field per
Env-Wq
Answer: D
Rationale: Perc test determines soil absorption rate minutes per inch at proposed depth, presoak required, sizing leach field based on rate.
25. A 4-bedroom home in NH with 2.5 gpm well produces 600 gpd design flow. What size septic tank is required per NH rules?
A. 750 gallons
B. 500 gallons
