Stormwater Management Technician Mock
Exam – Full Practice Set with Explanations
(2025 Update)
1. What is the primary purpose of a stormwater management
system?
a) To store potable water
b) To collect and treat industrial wastewater
c) To control the quantity and quality of runoff from rainfall
events
d) To prevent groundwater recharge
Rationale: Stormwater systems are designed to manage both the
volume and pollutant load of runoff from impervious surfaces,
protecting water quality and reducing flooding.
2. Which regulation primarily governs stormwater discharges in the
U.S.?
a) Safe Drinking Water Act
b) Clean Air Act
c) Clean Water Act (CWA)
d) Resource Conservation and Recovery Act
Rationale: The Clean Water Act established the NPDES permit
system, which regulates stormwater discharges to surface
waters.
3. What is the main goal of Best Management Practices (BMPs) in
stormwater management?
a) To increase runoff speed
b) To reduce pollution and runoff volume
c) To store drinking water
, d) To monitor stormwater only
Rationale: BMPs are structural or procedural measures designed
to reduce pollutant loads and manage runoff quantity.
4. What is a detention basin used for?
a) Permanent storage of stormwater
b) Treating wastewater
c) Temporarily storing stormwater to reduce peak flow
d) Enhancing infiltration only
Rationale: Detention basins hold water temporarily during
storms to control downstream flooding.
5. Which of the following is an example of a structural BMP?
a) Employee training
b) Street sweeping
c) Constructed wetland
d) Public education
Rationale: Structural BMPs involve physical facilities like
wetlands or retention basins to treat or control runoff.
6. What is the primary pollutant of concern in urban stormwater
runoff?
a) Dissolved oxygen
b) Sediment
c) Chlorine
d) Ammonia
Rationale: Sediment from construction and erosion is the most
common pollutant affecting stormwater quality.
7. What does “illicit discharge” refer to?
a) Stormwater entering the sanitary sewer
b) Any non-stormwater flow entering the storm drain system
c) Rainwater collection for irrigation
, d) Overflow during a storm event
Rationale: Illicit discharges are unauthorized flows such as
sewage, wash water, or chemicals entering storm drains.
8. A vegetated swale primarily functions to:
a) Increase runoff velocity
b) Divert flow into pipes
c) Filter and infiltrate stormwater through vegetation and soil
d) Store large volumes of water
Rationale: Swales slow and filter runoff, promoting infiltration
and reducing pollutant loads.
9. Which BMP is most effective for removing nutrients like nitrogen
and phosphorus?
a) Oil-water separator
b) Detention basin
c) Constructed wetland
d) Catch basin
Rationale: Constructed wetlands provide biological treatment
processes that remove nutrients and organic matter.
10. What is the main function of an erosion control blanket?
a) Improve drainage
b) Stabilize soil and prevent erosion on slopes
c) Reduce infiltration
d) Absorb pollutants
Rationale: Erosion control blankets protect exposed soil by
stabilizing it and allowing vegetation to establish.
11. When inspecting a stormwater BMP, what should be
checked first?
a) Depth of pond
b) Color of vegetation
Exam – Full Practice Set with Explanations
(2025 Update)
1. What is the primary purpose of a stormwater management
system?
a) To store potable water
b) To collect and treat industrial wastewater
c) To control the quantity and quality of runoff from rainfall
events
d) To prevent groundwater recharge
Rationale: Stormwater systems are designed to manage both the
volume and pollutant load of runoff from impervious surfaces,
protecting water quality and reducing flooding.
2. Which regulation primarily governs stormwater discharges in the
U.S.?
a) Safe Drinking Water Act
b) Clean Air Act
c) Clean Water Act (CWA)
d) Resource Conservation and Recovery Act
Rationale: The Clean Water Act established the NPDES permit
system, which regulates stormwater discharges to surface
waters.
3. What is the main goal of Best Management Practices (BMPs) in
stormwater management?
a) To increase runoff speed
b) To reduce pollution and runoff volume
c) To store drinking water
, d) To monitor stormwater only
Rationale: BMPs are structural or procedural measures designed
to reduce pollutant loads and manage runoff quantity.
4. What is a detention basin used for?
a) Permanent storage of stormwater
b) Treating wastewater
c) Temporarily storing stormwater to reduce peak flow
d) Enhancing infiltration only
Rationale: Detention basins hold water temporarily during
storms to control downstream flooding.
5. Which of the following is an example of a structural BMP?
a) Employee training
b) Street sweeping
c) Constructed wetland
d) Public education
Rationale: Structural BMPs involve physical facilities like
wetlands or retention basins to treat or control runoff.
6. What is the primary pollutant of concern in urban stormwater
runoff?
a) Dissolved oxygen
b) Sediment
c) Chlorine
d) Ammonia
Rationale: Sediment from construction and erosion is the most
common pollutant affecting stormwater quality.
7. What does “illicit discharge” refer to?
a) Stormwater entering the sanitary sewer
b) Any non-stormwater flow entering the storm drain system
c) Rainwater collection for irrigation
, d) Overflow during a storm event
Rationale: Illicit discharges are unauthorized flows such as
sewage, wash water, or chemicals entering storm drains.
8. A vegetated swale primarily functions to:
a) Increase runoff velocity
b) Divert flow into pipes
c) Filter and infiltrate stormwater through vegetation and soil
d) Store large volumes of water
Rationale: Swales slow and filter runoff, promoting infiltration
and reducing pollutant loads.
9. Which BMP is most effective for removing nutrients like nitrogen
and phosphorus?
a) Oil-water separator
b) Detention basin
c) Constructed wetland
d) Catch basin
Rationale: Constructed wetlands provide biological treatment
processes that remove nutrients and organic matter.
10. What is the main function of an erosion control blanket?
a) Improve drainage
b) Stabilize soil and prevent erosion on slopes
c) Reduce infiltration
d) Absorb pollutants
Rationale: Erosion control blankets protect exposed soil by
stabilizing it and allowing vegetation to establish.
11. When inspecting a stormwater BMP, what should be
checked first?
a) Depth of pond
b) Color of vegetation
