NEW HAMPSHIRE SEPTIC INSTALLER EXAM 3 –
SITE CONDITIONS, SETBACKS, EDAS &
TROUBLESHOOTING – 400 QUESTIONS
1. What is the primary state regulation governing the design and installation of individual sewage
disposal systems (ISDS) in New Hampshire?
A) RSA 485-A and Env-Wq 1000
B) RSA 100-A and Env-Ws 500
C) RSA 200-B and Env-Air 300
D) RSA 300-C and Env-Water 200
Answer: A
Rationale: The New Hampshire septic system installer exam requires a working knowledge of RSA 485-A
and Env-Wq 1000, which govern ISDS design, installation, and permitting in the state.
2. What is the minimum required setback from a septic tank to a property line in New Hampshire
under state rules?
A) 5 feet
B) 10 feet
C) 20 feet
D) 25 feet
Answer: B
Rationale: Under Env-Wq 1008.04, state rules allow an ISDS to be installed as close as 10 feet to the
property line, though local ordinances may require greater distances.
3. What is the required setback from an ISDS component to a well under New Hampshire state rules?
A) 25 feet
B) 50 feet
C) 75 feet
D) 100 feet
Answer: C
,Rationale: State regulations establish a protective well radius, and an ISDS may be installed closer than 75
feet to a well only under specific conditions with a recorded release form.
4. What is the minimum setback from a leach field to surface water in New Hampshire?
A) 25 feet
B) 50 feet
C) 75 feet
D) 100 feet
Answer: C
Rationale: Env-Wq 1008 requires a setback of 75 feet from all surface waters for both septic tanks and
leachfields.
5. What is the minimum setback from a leach field to wetlands in New Hampshire?
A) 25 feet
B) 50 to 75 feet
C) 100 feet
D) 150 feet
Answer: B
Rationale: State regulations require a setback of 50 to 75 feet from wetlands, depending on the type of
wetland soils.
6. What is the minimum vertical separation between the bottom of an EDA and bedrock or
impermeable substratum for a new system?
A) 1 foot
B) 2 feet
C) 3 feet
D) 4 feet
Answer: D
Rationale: Env-Wq 1014.07 requires that the bottom of an EDA be at least 4 feet above bedrock or any other
impermeable substratum for new systems.
2
,7. For a replacement system serving a single-family residence with no expansion, what is the
minimum vertical separation between the bottom of the EDA and bedrock?
A) 1 foot
B) 2 feet
C) 3 feet
D) 4 feet
Answer: B
Rationale: For replacement systems, the bottom of the EDA shall be as close to 4 feet above bedrock as
possible, and in no case less than 2 feet above bedrock if a conventional system is used.
8. What is the minimum depth to seasonal high-water table (SHWT) for a standard leach field in New
Hampshire?
A) 6 inches
B) 12 inches
C) 24 inches
D) 36 inches
Answer: B
Rationale: New Hampshire rules require a minimum 12-inch vertical separation to the seasonal high-water
table for a standard leach field, though 24 inches is required in many cases depending on system type and
loading rate.
9. What does the percolation test evaluate?
A) Soil color
B) Soil pH
C) The rate at which water moves through soil
D) Organic content
Answer: C
Rationale: A percolation test measures the infiltration rate of water through soil, which is used to size the
absorption area of a septic system.
10. What is the most reliable indicator of a seasonal high-water table?
A) Leaf litter
B) Redoximorphic features
3
, C) Soil pH
D) Soil texture alone
Answer: B
Rationale: Redoximorphic features (mottling and gray colors) indicate prolonged saturation and are the
required indicators for evaluating seasonal high-water table.
11. What is the primary function of a septic tank?
A) Aerate wastewater
B) Separate solids from wastewater
C) Chlorinate effluent
D) Reduce nitrates
Answer: B
Rationale: The septic tank settles solids and allows clarified effluent to exit to the leach field for further
treatment.
12. What is the minimum septic tank size for a 3-bedroom home in New Hampshire?
A) 500 gallons
B) 750 gallons
C) 1,000 gallons
D) 1,200 gallons
Answer: C
Rationale: New Hampshire standards specify a minimum 1,000-gallon tank for up to three bedrooms, with
250 additional gallons per additional bedroom.
13. Which soil texture generally has the slowest infiltration rate?
A) Sand
B) Loamy sand
C) Silt loam
D) Clay
Answer: D
Rationale: Clay particles are very small, which reduces pore size and significantly slows infiltration through
the soil.
4
SITE CONDITIONS, SETBACKS, EDAS &
TROUBLESHOOTING – 400 QUESTIONS
1. What is the primary state regulation governing the design and installation of individual sewage
disposal systems (ISDS) in New Hampshire?
A) RSA 485-A and Env-Wq 1000
B) RSA 100-A and Env-Ws 500
C) RSA 200-B and Env-Air 300
D) RSA 300-C and Env-Water 200
Answer: A
Rationale: The New Hampshire septic system installer exam requires a working knowledge of RSA 485-A
and Env-Wq 1000, which govern ISDS design, installation, and permitting in the state.
2. What is the minimum required setback from a septic tank to a property line in New Hampshire
under state rules?
A) 5 feet
B) 10 feet
C) 20 feet
D) 25 feet
Answer: B
Rationale: Under Env-Wq 1008.04, state rules allow an ISDS to be installed as close as 10 feet to the
property line, though local ordinances may require greater distances.
3. What is the required setback from an ISDS component to a well under New Hampshire state rules?
A) 25 feet
B) 50 feet
C) 75 feet
D) 100 feet
Answer: C
,Rationale: State regulations establish a protective well radius, and an ISDS may be installed closer than 75
feet to a well only under specific conditions with a recorded release form.
4. What is the minimum setback from a leach field to surface water in New Hampshire?
A) 25 feet
B) 50 feet
C) 75 feet
D) 100 feet
Answer: C
Rationale: Env-Wq 1008 requires a setback of 75 feet from all surface waters for both septic tanks and
leachfields.
5. What is the minimum setback from a leach field to wetlands in New Hampshire?
A) 25 feet
B) 50 to 75 feet
C) 100 feet
D) 150 feet
Answer: B
Rationale: State regulations require a setback of 50 to 75 feet from wetlands, depending on the type of
wetland soils.
6. What is the minimum vertical separation between the bottom of an EDA and bedrock or
impermeable substratum for a new system?
A) 1 foot
B) 2 feet
C) 3 feet
D) 4 feet
Answer: D
Rationale: Env-Wq 1014.07 requires that the bottom of an EDA be at least 4 feet above bedrock or any other
impermeable substratum for new systems.
2
,7. For a replacement system serving a single-family residence with no expansion, what is the
minimum vertical separation between the bottom of the EDA and bedrock?
A) 1 foot
B) 2 feet
C) 3 feet
D) 4 feet
Answer: B
Rationale: For replacement systems, the bottom of the EDA shall be as close to 4 feet above bedrock as
possible, and in no case less than 2 feet above bedrock if a conventional system is used.
8. What is the minimum depth to seasonal high-water table (SHWT) for a standard leach field in New
Hampshire?
A) 6 inches
B) 12 inches
C) 24 inches
D) 36 inches
Answer: B
Rationale: New Hampshire rules require a minimum 12-inch vertical separation to the seasonal high-water
table for a standard leach field, though 24 inches is required in many cases depending on system type and
loading rate.
9. What does the percolation test evaluate?
A) Soil color
B) Soil pH
C) The rate at which water moves through soil
D) Organic content
Answer: C
Rationale: A percolation test measures the infiltration rate of water through soil, which is used to size the
absorption area of a septic system.
10. What is the most reliable indicator of a seasonal high-water table?
A) Leaf litter
B) Redoximorphic features
3
, C) Soil pH
D) Soil texture alone
Answer: B
Rationale: Redoximorphic features (mottling and gray colors) indicate prolonged saturation and are the
required indicators for evaluating seasonal high-water table.
11. What is the primary function of a septic tank?
A) Aerate wastewater
B) Separate solids from wastewater
C) Chlorinate effluent
D) Reduce nitrates
Answer: B
Rationale: The septic tank settles solids and allows clarified effluent to exit to the leach field for further
treatment.
12. What is the minimum septic tank size for a 3-bedroom home in New Hampshire?
A) 500 gallons
B) 750 gallons
C) 1,000 gallons
D) 1,200 gallons
Answer: C
Rationale: New Hampshire standards specify a minimum 1,000-gallon tank for up to three bedrooms, with
250 additional gallons per additional bedroom.
13. Which soil texture generally has the slowest infiltration rate?
A) Sand
B) Loamy sand
C) Silt loam
D) Clay
Answer: D
Rationale: Clay particles are very small, which reduces pore size and significantly slows infiltration through
the soil.
4
