Certified Stormwater Inspector Exam With
Actual Questions & Verified Answers, Plus
Explained Rationales/Expert Verified For
Guaranteed 100% Pass 2026/Latest
Update/Instant Download Pdf
1. What is the primary purpose of a stormwater inspection?
A) To increase water usage
B) To prevent flooding and water pollution
C) To reduce sewage treatment costs
D) To monitor drinking water quality
B) To prevent flooding and water pollution
Rationale: The main goal of stormwater inspections is to ensure
stormwater systems function properly and prevent pollutants
from entering water bodies.
2. Which of the following is considered a Best Management Practice
(BMP) for stormwater?
A) Illicit discharge
B) Vegetated swales
C) Open dumping
D) Paved parking lots
B) Vegetated swales
Rationale: Vegetated swales are designed to slow runoff, filter
pollutants, and promote infiltration.
3. During an inspection, you notice sediment accumulation in a
storm drain. What should you do first?
, A) Ignore it
B) Document it and schedule maintenance
C) Immediately remove all sediment yourself
D) Divert the flow
B) Document it and schedule maintenance
Rationale: Inspectors should document issues and coordinate
proper maintenance rather than performing unauthorized
removal.
4. What is an illicit discharge?
A) Rainwater runoff from rooftops
B) Any non-stormwater flow into the stormwater system
C) Groundwater infiltration
D) Street sweeping water
B) Any non-stormwater flow into the stormwater system
Rationale: Illicit discharges are prohibited flows that can
contaminate stormwater systems and receiving waters.
5. How often should stormwater outfalls typically be inspected?
A) Once every 10 years
B) Monthly
C) Annually or per permit requirements
D) Never
C) Annually or per permit requirements
Rationale: Inspections are usually required annually or as
outlined in a municipal stormwater permit.
6. What is the primary pollutant of concern in urban stormwater
runoff?
A) Nitrogen gas
B) Sediment
C) Chlorine
, D) Sodium
B) Sediment
Rationale: Sediment from construction sites and urban surfaces
is a major pollutant affecting waterways.
7. Which of the following describes a detention basin?
A) A natural wetland
B) A structure designed to temporarily store stormwater and
release it slowly
C) A sewer pipe
D) A drinking water reservoir
B) A structure designed to temporarily store stormwater and
release it slowly
Rationale: Detention basins manage peak flow rates and reduce
flooding risk.
8. What is the purpose of a rain garden?
A) To reduce indoor water use
B) To filter and infiltrate stormwater
C) To provide recreational space
D) To store drinking water
B) To filter and infiltrate stormwater
Rationale: Rain gardens are vegetated areas that capture runoff,
filter pollutants, and promote infiltration.
9. Which method is best for identifying erosion problems in a
stormwater system?
A) Visual inspection
B) Chemical analysis
C) Sound testing
D) pH testing
A) Visual inspection
, Rationale: Erosion is typically identified by observing exposed
soil, rills, or sediment deposits.
10. What is a common sign of a blocked stormwater inlet?
A) Excessive water pooling upstream
B) Clear water flow
C) Dry pipes
D) Water quality improvement
A) Excessive water pooling upstream
Rationale: Obstructions prevent proper drainage, causing
localized flooding.
11. Which of the following is a priority during a post-
construction stormwater inspection?
A) Landscaping aesthetics
B) BMP functionality
C) Road signage
D) Trash collection
B) BMP functionality
Rationale: Post-construction inspections focus on ensuring that
stormwater controls are operating as designed.
12. What is the main goal of erosion control measures?
A) Reduce water supply
B) Minimize soil loss and sedimentation
C) Increase water temperature
D) Reduce property value
B) Minimize soil loss and sedimentation
Rationale: Erosion control measures protect water quality by
preventing sediment from entering stormwater systems.
13. When inspecting a detention pond, which of the following
should be checked?
Actual Questions & Verified Answers, Plus
Explained Rationales/Expert Verified For
Guaranteed 100% Pass 2026/Latest
Update/Instant Download Pdf
1. What is the primary purpose of a stormwater inspection?
A) To increase water usage
B) To prevent flooding and water pollution
C) To reduce sewage treatment costs
D) To monitor drinking water quality
B) To prevent flooding and water pollution
Rationale: The main goal of stormwater inspections is to ensure
stormwater systems function properly and prevent pollutants
from entering water bodies.
2. Which of the following is considered a Best Management Practice
(BMP) for stormwater?
A) Illicit discharge
B) Vegetated swales
C) Open dumping
D) Paved parking lots
B) Vegetated swales
Rationale: Vegetated swales are designed to slow runoff, filter
pollutants, and promote infiltration.
3. During an inspection, you notice sediment accumulation in a
storm drain. What should you do first?
, A) Ignore it
B) Document it and schedule maintenance
C) Immediately remove all sediment yourself
D) Divert the flow
B) Document it and schedule maintenance
Rationale: Inspectors should document issues and coordinate
proper maintenance rather than performing unauthorized
removal.
4. What is an illicit discharge?
A) Rainwater runoff from rooftops
B) Any non-stormwater flow into the stormwater system
C) Groundwater infiltration
D) Street sweeping water
B) Any non-stormwater flow into the stormwater system
Rationale: Illicit discharges are prohibited flows that can
contaminate stormwater systems and receiving waters.
5. How often should stormwater outfalls typically be inspected?
A) Once every 10 years
B) Monthly
C) Annually or per permit requirements
D) Never
C) Annually or per permit requirements
Rationale: Inspections are usually required annually or as
outlined in a municipal stormwater permit.
6. What is the primary pollutant of concern in urban stormwater
runoff?
A) Nitrogen gas
B) Sediment
C) Chlorine
, D) Sodium
B) Sediment
Rationale: Sediment from construction sites and urban surfaces
is a major pollutant affecting waterways.
7. Which of the following describes a detention basin?
A) A natural wetland
B) A structure designed to temporarily store stormwater and
release it slowly
C) A sewer pipe
D) A drinking water reservoir
B) A structure designed to temporarily store stormwater and
release it slowly
Rationale: Detention basins manage peak flow rates and reduce
flooding risk.
8. What is the purpose of a rain garden?
A) To reduce indoor water use
B) To filter and infiltrate stormwater
C) To provide recreational space
D) To store drinking water
B) To filter and infiltrate stormwater
Rationale: Rain gardens are vegetated areas that capture runoff,
filter pollutants, and promote infiltration.
9. Which method is best for identifying erosion problems in a
stormwater system?
A) Visual inspection
B) Chemical analysis
C) Sound testing
D) pH testing
A) Visual inspection
, Rationale: Erosion is typically identified by observing exposed
soil, rills, or sediment deposits.
10. What is a common sign of a blocked stormwater inlet?
A) Excessive water pooling upstream
B) Clear water flow
C) Dry pipes
D) Water quality improvement
A) Excessive water pooling upstream
Rationale: Obstructions prevent proper drainage, causing
localized flooding.
11. Which of the following is a priority during a post-
construction stormwater inspection?
A) Landscaping aesthetics
B) BMP functionality
C) Road signage
D) Trash collection
B) BMP functionality
Rationale: Post-construction inspections focus on ensuring that
stormwater controls are operating as designed.
12. What is the main goal of erosion control measures?
A) Reduce water supply
B) Minimize soil loss and sedimentation
C) Increase water temperature
D) Reduce property value
B) Minimize soil loss and sedimentation
Rationale: Erosion control measures protect water quality by
preventing sediment from entering stormwater systems.
13. When inspecting a detention pond, which of the following
should be checked?
