Certified Stormwater Manager (CSM) — Questions and Answers

Question 1: Which of the following outfall observations would be LEAST likely to indicate an illicit discharge during a dry-weather field screening visit?

Oily sheen on the water surface near the outfall
Bright orange or reddish staining around the outfall pipe
A small trickle of clear, odorless water at an outfall 72 hours after a significant rain event (Correct answer)
A persistent flow with a sewage odor and gray coloration

Correct answer: A small trickle of clear, odorless water at an outfall 72 hours after a significant rain event

A small trickle of clear, odorless water 72 hours after significant rainfall is likely base flow or subsurface drainage, a common allowable condition, and is the least indicative of an illicit discharge.

Question 2: What should a practitioner do when regulations conflict with employer policies?

Follow the regulation, as legal requirements supersede employer policies (Correct answer)
Follow whichever is easier to comply with
Always follow employer policies
Ignore both and use personal judgment

Correct answer: Follow the regulation, as legal requirements supersede employer policies

Legal and regulatory requirements always take precedence over employer policies, and practitioners have a professional obligation to comply with applicable laws.

Question 3: A stormwater inspector notices blue-green algae (cyanobacteria) blooms in a retention basin. What is the PRIMARY immediate action?

Add chlorine tablets directly to the pond
Collect a water sample with bare hands
Restrict access and notify supervisors (Correct answer)
Continue inspection without PPE

Correct answer: Restrict access and notify supervisors

Cyanobacteria can produce hepatotoxic and neurotoxic compounds, so restricting access and notifying supervisors is the correct first response.

Question 4: Which condition would most likely trigger a requirement to develop a Corrective Action Report under the EPA Construction General Permit?

Installing a concrete washout area more than 50 feet from the storm drain
Discovering that a BMP has failed to perform as designed and a discharge occurred (Correct answer)
Changing the construction contractor mid-project
Completing final grading on a slope steeper than 3:1

Correct answer: Discovering that a BMP has failed to perform as designed and a discharge occurred

When inspections or reports reveal that a BMP has failed and may have caused a discharge of pollutants, the CGP requires a corrective action to be documented and implemented promptly.

Question 5: What is the 'first flush' phenomenon in urban stormwater management?

The flushing of sediment from pipes after a dry period when the first rainstorm occurs
The first discharge from a stormwater outfall following construction of a new development
The disproportionately high pollutant concentrations found in the initial portion of stormwater runoff at the beginning of a storm event (Correct answer)
The initial clean water that enters a storm drain before it mixes with street runoff

Correct answer: The disproportionately high pollutant concentrations found in the initial portion of stormwater runoff at the beginning of a storm event

The first flush refers to the phenomenon where the initial runoff from an impervious surface carries the highest concentrations of accumulated pollutants such as oil, heavy metals, and nutrients, often representing a disproportionate share of the total pollutant load.

Question 6: Under the Construction General Permit, how frequently must a qualified person conduct site inspections during active grading when there is no rain?

Every 14 calendar days (Correct answer)
Daily
Monthly
Every 7 calendar days

Correct answer: Every 14 calendar days

The EPA CGP requires routine inspections at least every 14 calendar days during active construction, with post-storm event inspections within 24 hours of a qualifying event.

Question 7: What is runoff?

Air humidity levels.
Surface water that flows across the land (Correct answer)
Water absorbed by plants.
Underground water flow.

Correct answer: Surface water that flows across the land

Runoff refers to the portion of precipitation or irrigation water that flows over the land surface, rather than infiltrating into the ground or evaporating. This surface flow can pick up pollutants like sediment, chemicals, and debris, carrying them into storm drains and ultimately into rivers, lakes, and oceans. Managing runoff is a key aspect of stormwater pollution control.

Question 8: Which document must a stormwater manager consult to determine the legal notification requirements to adjacent property owners when emergency bypass pumping may cause nuisance flooding?

FEMA flood insurance rate maps
The facility SWPPP
The municipal code and NPDES permit conditions (Correct answer)
The Incident Action Plan

Correct answer: The municipal code and NPDES permit conditions

Notification requirements for bypass operations are governed by NPDES permit conditions and local municipal code, which specify timelines and affected parties.

Question 9: NPDES MS4 permits typically require municipalities to prohibit illicit discharges through a local regulatory mechanism. What is the most common tool used to establish this legal authority?

A local stormwater ordinance or municipal code provision that prohibits non-stormwater discharges to the MS4 (Correct answer)
A conditional use permit issued to each property owner
A memorandum of understanding with the state environmental agency
A resolution passed by the city council during an open meeting

Correct answer: A local stormwater ordinance or municipal code provision that prohibits non-stormwater discharges to the MS4

A local stormwater ordinance is the standard legal mechanism that grants the municipality authority to prohibit illicit discharges, investigate suspected violations, and enforce corrective actions.

Question 10: What is the primary purpose of a constructed wetland in a stormwater management system?

Increase runoff velocity
Prevent groundwater recharge
Provide water quality treatment through biological processes (Correct answer)
Replace detention storage

Correct answer: Provide water quality treatment through biological processes

Constructed wetlands use aquatic vegetation and microbial activity to remove nutrients, sediments, and other pollutants from stormwater.

Question 11: What is the primary stormwater management function of a vegetated swale?

To rapidly convey runoff off-site at maximum velocity to prevent flooding
To store large volumes of runoff for extended periods for water quality improvement
To convey stormwater runoff while slowing its velocity, promoting infiltration, and filtering pollutants through the vegetation and soil (Correct answer)
To sample runoff for pollutant analysis at regular monitoring stations

Correct answer: To convey stormwater runoff while slowing its velocity, promoting infiltration, and filtering pollutants through the vegetation and soil

Vegetated swales are shallow, grass-lined channels that slow runoff, allow infiltration into the soil, and filter suspended solids and nutrients through contact with vegetation and soil media.

Question 12: Which of the following best describes the role of public education and outreach in an effective IDDE program?

It is only required for Phase I MS4 permits in large urban areas
It serves primarily to meet permit reporting requirements with minimal operational impact
It reduces illicit discharges by informing residents and businesses about what can legally enter storm drains and how to report illegal dumping (Correct answer)
It is the responsibility of the state environmental agency, not the MS4 operator

Correct answer: It reduces illicit discharges by informing residents and businesses about what can legally enter storm drains and how to report illegal dumping

Public education and outreach reduce illicit discharges by raising awareness of proper disposal practices and creating a community reporting network that extends the reach of limited inspection staff.

Question 13: Which EPA Phase II rule first extended NPDES stormwater permit requirements to small MS4s?

1999 Phase II Final Rule (Correct answer)
2016 WOTUS Rule
2010 Small MS4 Rule
1990 Phase I Rule

Correct answer: 1999 Phase II Final Rule

The 1999 Phase II Final Rule (effective March 2003) expanded NPDES coverage to small MS4s in urbanized areas and smaller construction sites.

Question 14: A stormwater manager receives turbidity readings of 5, 6, 200, 7, and 5 NTU from five consecutive samples. The value of 200 NTU is most likely a(n):

Calibration standard result
Normal diurnal variation
Representative peak event value
Outlier requiring investigation (Correct answer)

Correct answer: Outlier requiring investigation

A single value orders of magnitude above the rest of the dataset is a statistical outlier and should be investigated for sampling error, equipment malfunction, or a true transient event.

Question 15: What is considered an illicit discharge?

Rainwater from rooftops.
Unauthorized pollutants into storm drains (Correct answer)
Snow melt from parking lots.
Clean drinking water flows.

Correct answer: Unauthorized pollutants into storm drains

An illicit discharge refers to any discharge to an MS4 that is not composed entirely of stormwater, except for discharges allowed under an NPDES permit or specifically exempted by regulation. Common illicit discharges include sanitary wastewater, car wash waste, oil, chemicals, and improper disposal of trash, all of which can severely pollute receiving waters.

Question 16: What should be done immediately after a needlestick injury?

Document it at the end of the shift
Apply a bandage and continue working
Wait to see if symptoms develop
Wash the area, report the incident, and seek medical evaluation (Correct answer)

Correct answer: Wash the area, report the incident, and seek medical evaluation

Immediate wound care, incident reporting, and medical evaluation are essential after needlestick injuries to minimize infection risk and ensure proper follow-up.

Question 17: Which federal agency shares authority with EPA over wetland fill permits under Section 404 of the Clean Water Act?

National Marine Fisheries Service
U.S. Army Corps of Engineers (Correct answer)
Bureau of Land Management
U.S. Fish and Wildlife Service

Correct answer: U.S. Army Corps of Engineers

The U.S. Army Corps of Engineers is the primary permitting authority for Section 404 permits, while EPA retains oversight and veto authority.

Question 18: A stormwater management plan includes a rainwater harvesting cistern. Which design consideration is most important to ensure the cistern provides both water quality and volume reduction benefits?

Making the cistern as large as possible to store the entire annual runoff volume
Ensuring the cistern overflow discharges directly to a storm drain without treatment
Positioning the cistern above grade to maximize gravity flow to end uses
Sizing the cistern with sufficient drawdown between storms to provide available storage capacity (Correct answer)

Correct answer: Sizing the cistern with sufficient drawdown between storms to provide available storage capacity

A cistern only provides volume reduction if it has available capacity when the next storm arrives; adequate drawdown through planned reuse is essential for stormwater management benefits.

Question 19: A portable multiparameter sonde is deployed in a receiving stream for continuous monitoring. Which combination of parameters would it typically measure simultaneously?

BOD, TSS, and heavy metals
Total phosphorus, nitrate, and fecal coliform
Rainfall depth, flow velocity, and sediment load
Temperature, pH, dissolved oxygen, and specific conductance (Correct answer)

Correct answer: Temperature, pH, dissolved oxygen, and specific conductance

Multiparameter sondes typically include sensors for temperature, pH, dissolved oxygen, and specific conductance (and sometimes turbidity), all measurable electronically in real time.

Question 20: What is the term for the process of systematically closing down emergency operations and returning to normal stormwater management activities after a major incident?

Demobilization (Correct answer)
Remediation
Incident stabilization
Restoration

Correct answer: Demobilization

Demobilization in ICS refers to the planned, orderly release of resources and personnel and the return to pre-incident operational status.

Question 21: Under the National Incident Management System (NIMS), the Unified Command structure is used in stormwater emergencies when:

Federal resources are not required
A single agency has full jurisdictional authority
Multiple agencies with different legal authorities are involved (Correct answer)
The incident is limited to one geographic location

Correct answer: Multiple agencies with different legal authorities are involved

Unified Command is activated when multiple agencies with different jurisdictions or legal authorities must coordinate a joint response to the same incident.

Question 22: A stage-discharge relationship (rating curve) for a stream gauging station is developed by:

Applying the rational method with local rainfall data
Correlating measured water surface elevations with measured streamflow discharges (Correct answer)
Using Manning's equation with assumed roughness values
Calculating the cross-sectional area times average velocity from Manning's n

Correct answer: Correlating measured water surface elevations with measured streamflow discharges

Rating curves are developed empirically by repeatedly measuring both stage (water surface elevation) and discharge at a station over a range of flow conditions.

Question 23: In watershed delineation, a 'pour point' refers to:

A point where two stream tributaries merge
The outlet or lowest point through which all watershed runoff exits (Correct answer)
The highest elevation point on the watershed boundary
The location of maximum soil infiltration rate

Correct answer: The outlet or lowest point through which all watershed runoff exits

The pour point (or watershed outlet) is the single point at the lowest elevation through which all surface water within the delineated watershed drains.

Question 24: Which maintenance activity is most critical during the first two years after installation of a bioretention facility?

Annual replacement of the entire filter media
Monthly dredging of accumulated sediment from the surface
Irrigation and vegetation management to ensure plant establishment (Correct answer)
Weekly inspection of underdrain outflow volume

Correct answer: Irrigation and vegetation management to ensure plant establishment

Adequate irrigation and weed control during the plant establishment period (typically 1–2 years) is critical to achieve the designed vegetation cover that supports long-term BMP performance.

Question 25: A sanitary sewer overflow (SSO) discharges into a storm drain and reaches a public beach during a major rain event. The stormwater manager's first notification should go to:

The Army Corps of Engineers permit office
The local newspaper
The public health department and beach management authority (Correct answer)
The facility's legal counsel

Correct answer: The public health department and beach management authority

SSO contamination of recreational waters triggers immediate public health notification requirements to enable beach closures and protect swimmers.

Question 26: A frequency analysis of annual peak streamflow data is used to:

Calculate the average annual sediment load of a river
Estimate the probability of occurrence of floods of various magnitudes (Correct answer)
Calibrate Manning's roughness coefficient for a channel reach
Determine the average baseflow contribution to annual streamflow

Correct answer: Estimate the probability of occurrence of floods of various magnitudes

Flood frequency analysis fits statistical distributions to annual peak flow records to estimate the probability (return period) associated with flood events of various magnitudes.

Question 27: Under NPDES MS4 permits, which of the following discharges is typically listed as an allowable non-stormwater discharge and is NOT considered illicit?

Discharge from portable toilet cleanouts
Washwater from washing out concrete mixers
Wastewater from floor drains in auto repair shops
Lawn watering and landscape irrigation runoff (Correct answer)

Correct answer: Lawn watering and landscape irrigation runoff

Lawn watering and landscape irrigation runoff are explicitly listed in most NPDES MS4 permits as allowable non-stormwater discharges, provided they do not cause or contribute to water quality violations.

Question 28: Which factor most directly reduces the lag time between precipitation and peak streamflow in an urbanized watershed?

Increased tree canopy and forest cover
Expansion of riparian buffer zones
Construction of detention ponds
Increased impervious cover and storm sewer networks (Correct answer)

Correct answer: Increased impervious cover and storm sewer networks

Impervious surfaces and storm sewers speed overland and channel flow, shortening the time for water to travel from the watershed to the outlet.

Question 29: When designing a vegetated filter strip, the recommended maximum slope to ensure uniform sheet flow and adequate treatment is:

5% (Correct answer)
15%
2%
10%

Correct answer: 5%

Filter strips are typically designed with slopes of 2–5%, with 5% being a common upper limit to maintain sheet flow and prevent channelization that bypasses treatment.

Question 30: The 'first flush' phenomenon refers to which stormwater quality characteristic?

The first annual inspection flush required for underground detention systems
The rapid groundwater recharge that occurs at the beginning of each wet season
The disproportionately high pollutant concentrations carried in early runoff compared to later portions of a storm (Correct answer)
The initial surge of clean water that flushes bioretention media at the start of each storm

Correct answer: The disproportionately high pollutant concentrations carried in early runoff compared to later portions of a storm

The first flush describes elevated pollutant concentrations in the initial runoff from impervious surfaces as accumulated dry-weather deposits are mobilized by early rainfall.

Certified Stormwater Manager (CSM)

The CSM certification, administered by APWA, validates professional competency in municipal stormwater program management including regulatory compliance, hydrology, erosion and sediment control, illicit discharge elimination, BMP design, and program administration.

Questions

35 min

Time Limit

70%

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