Certified Erosion, Sediment, and Storm Water Inspector (CESSWI) Exam — Questions and Answers

Question 1: What is the goal of stormwater management?

Flood construction sites
Reduce pollution and manage flow (Correct answer)
Increase erosion
Raise water levels

Correct answer: Reduce pollution and manage flow

The goal of stormwater management is to effectively control the quantity and quality of runoff generated from rainfall. This involves reducing the volume and velocity of stormwater to prevent flooding and erosion, while also treating it to remove pollutants before it enters natural water bodies. Comprehensive management protects infrastructure, human safety, and environmental health.

Question 2: Under good housekeeping practices, construction site dumpsters used for general solid waste should be:

Left uncovered to allow rainwater to drain naturally through the waste
Covered or lidded to prevent stormwater from contacting and mobilizing waste materials (Correct answer)
Positioned directly over storm drain inlets for convenient waste water disposal
Cleaned weekly by pressure washing, with wash water discharged to the nearest channel

Correct answer: Covered or lidded to prevent stormwater from contacting and mobilizing waste materials

Dumpsters should be covered to prevent rain from contacting waste, which can generate contaminated leachate that runs off as polluted stormwater.

Question 3: Which of the following is the most professional and effective way for a CESSWI to communicate a required corrective action to a contractor who is resistant to the finding?

Ignoring the contractor's concerns and stating that the report is final and non-negotiable.
Calmly referencing the specific SWPPP requirement or permit condition that is not being met and explaining the consequence of non-compliance. (Correct answer)
Offering to overlook the finding in exchange for fixing another, less expensive issue.
Threatening to report the contractor to the regulatory agency if they do not comply immediately.

Correct answer: Calmly referencing the specific SWPPP requirement or permit condition that is not being met and explaining the consequence of non-compliance.

The most professional approach is to be objective and fact-based. By tying the required action directly to a specific requirement in the SWPPP or permit, the inspector removes personal opinion from the discussion. It frames the issue as a matter of contractual and legal compliance rather than a personal conflict. This approach is firm, fair, and defensible.

Question 4: In a SWPPP, the 'good housekeeping' section typically covers:

Maintenance schedules for heavy equipment
Employee hygiene standards on the job site
Management of construction materials, waste, and spill prevention on-site (Correct answer)
Landscaping and aesthetic site maintenance

Correct answer: Management of construction materials, waste, and spill prevention on-site

Good housekeeping provisions in a SWPPP address storage, handling, and disposal of construction materials and wastes to prevent pollutants from reaching storm water.

Question 5: What is the recommended minimum distance from a sediment trap or basin outlet to a stream or sensitive receiving water?

25 feet
No minimum if outlet is vegetated
10 feet
50 feet (Correct answer)

Correct answer: 50 feet

A minimum 50-foot buffer between the outlet and receiving waters allows additional settling and energy dissipation before discharge reaches sensitive waterways.

Question 6: A bioretention cell is designed to treat stormwater through which primary set of processes?

Filtration, adsorption, biological uptake, and infiltration (Correct answer)
Gravity settling in a quiescent pool
Chemical coagulation and flocculation
UV disinfection and chlorination

Correct answer: Filtration, adsorption, biological uptake, and infiltration

Bioretention cells treat runoff through physical filtration through engineered media, adsorption to soil particles, biological uptake by plants, and infiltration into native soils.

Question 7: A site superintendent plans to use straw bales as the primary perimeter sediment control measure. As a CESSWI, what advice should you provide?

Suggest wrapping the straw bales in geotextile fabric to improve their filtering capacity.
Advise against using straw bales due to their high failure rate and suggest alternatives like silt fence or fiber rolls. (Correct answer)
Ensure the bales are tightly bound and staked securely to be effective.
Recommend using straw bales only for concentrated flow channels.

Correct answer: Advise against using straw bales due to their high failure rate and suggest alternatives like silt fence or fiber rolls.

Straw bale barriers have a high failure rate. They are prone to rotting, being displaced by runoff, and allowing water to flow around or underneath them. Professional guidance often recommends avoiding their use in favor of more reliable and effective BMPs such as silt fences, compost filter socks, or fiber rolls.

Question 8: An erosion control inspector is reviewing a SWPPP for a linear project (pipeline installation). Which unique erosion challenge must linear projects address that is less common on area grading projects?

Elevated grading equipment exhaust affecting vegetation establishment
Trench backfill settlement creating concentrated flow paths parallel to the installation corridor (Correct answer)
Proximity to residential structures requiring noise controls
Greater total disturbed acreage requiring additional BMPs

Correct answer: Trench backfill settlement creating concentrated flow paths parallel to the installation corridor

Linear project trenches frequently settle after backfill, creating low-gradient linear channels that concentrate runoff along the corridor and increase erosion risk.

Question 9: Which parameter is most useful for an inspector to record at a stormwater discharge point to quickly assess potential sediment impact without lab analysis?

Visual color and clarity of the discharged water (Correct answer)
Conductivity in microsiemens per centimeter
Flow rate measured with a weir board
Air temperature at time of inspection

Correct answer: Visual color and clarity of the discharged water

Visual assessment of water color and clarity is a quick field indicator of turbidity and suspended sediment that inspectors use at discharge points without lab equipment.

Question 10: What is the primary purpose of a 'discharge monitoring report' (DMR) in the context of stormwater permits for large construction sites?

To document the number of inspections completed in a reporting period
To formally report measured effluent quality data (e.g., turbidity, pH) to the regulatory agency as required by the permit (Correct answer)
To notify neighboring property owners of construction activity
To summarize labor costs associated with BMP installation

Correct answer: To formally report measured effluent quality data (e.g., turbidity, pH) to the regulatory agency as required by the permit

A DMR is the regulatory submission used to report actual water quality monitoring results to the permitting authority, demonstrating compliance with numeric effluent limits.

Question 11: Which of the following is the MOST common type of violation found during regulatory inspections of construction sites with a Stormwater Pollution Prevention Plan (SWPPP)?

Inadequate or missing inspection records and documentation. (Correct answer)
Improper concrete washout procedures.
Incorrect installation of erosion control blankets.
Failure to stabilize the construction entrance.

Correct answer: Inadequate or missing inspection records and documentation.

While all listed items can be violations, regulatory agencies frequently cite projects for failures in paperwork and documentation. This includes missing, incomplete, or falsified inspection logs, which are often considered the most common type of SWPPP violation.

Question 12: What is a retention basin used for?

Water drinking fountain
Store stormwater temporarily (Correct answer)
Support fish habitats
Block drainpipes

Correct answer: Store stormwater temporarily

A retention basin is a permanent pond designed to hold stormwater runoff for an extended period, allowing it to slowly infiltrate into the ground or be released at a controlled rate. This temporary storage helps to reduce peak flows during storm events, preventing downstream flooding and erosion, and also allows for some pollutant removal through settling and natural processes.

Question 13: What is the primary difference between infiltration trenches and infiltration basins as stormwater BMPs?

Trenches treat larger drainage areas than basins
Trenches are narrow, subsurface stone-filled features; basins are shallow surface depressions (Correct answer)
Basins require underdrain systems; trenches do not
Trenches use sand media; basins use gravel

Correct answer: Trenches are narrow, subsurface stone-filled features; basins are shallow surface depressions

Infiltration trenches are narrow excavations filled with stone aggregate that receive runoff and infiltrate it underground, while infiltration basins are open surface areas that allow ponded water to percolate into the soil.

Question 14: What does the term 'hydromodification' refer to in stormwater management?

Adding amendments to soil to increase infiltration rates
Changes in watershed hydrology caused by land development that alter flow frequency, duration, and magnitude (Correct answer)
The physical modification of stream channels through dredging
The chemical modification of stormwater pollutants through treatment

Correct answer: Changes in watershed hydrology caused by land development that alter flow frequency, duration, and magnitude

Hydromodification refers to alterations in the hydrologic regime of streams resulting from land development, including changes in peak flows, flow duration, and total runoff volume.

Question 15: A bioretention cell (rain garden) treats stormwater primarily through which combination of processes?

Filtration, infiltration, and biological uptake (Correct answer)
Coagulation and flocculation
Chlorination and UV disinfection
Gravitational settling only

Correct answer: Filtration, infiltration, and biological uptake

Bioretention cells use engineered soil media for filtration, underlying native soil for infiltration, and plants for biological nutrient uptake to achieve pollutant removal.

Question 16: Which USDA soil texture class is generally considered the most erodible by water?

Clay
Sandy clay
Silt loam (Correct answer)
Gravel

Correct answer: Silt loam

Silt loam soils are highly erodible because silt particles detach easily under raindrop impact and are readily transported by sheet flow.

Question 17: When an inspector identifies that a subcontractor—not the prime contractor—has caused an erosion violation, who bears regulatory responsibility?

The subcontractor alone bears all liability
The inspector bears responsibility for not catching it sooner
The local municipality is automatically liable
The permit holder (typically the owner or prime contractor) remains responsible and must ensure correction (Correct answer)

Correct answer: The permit holder (typically the owner or prime contractor) remains responsible and must ensure correction

Under most NPDES construction general permits, the permit holder is ultimately responsible for all earth-disturbing activities on the site, including subcontractor work.

Question 18: When evaluating a site's susceptibility to rill erosion, which combination of factors poses the greatest risk?

Steep slopes, bare silt loam soil, high-intensity rainfall (Correct answer)
Moderate slopes, gravelly soil, low rainfall
Flat slopes, clay soils, dense vegetation
Gentle slopes, sandy loam, moderate rainfall

Correct answer: Steep slopes, bare silt loam soil, high-intensity rainfall

Rill erosion is maximized by steep slopes that accelerate flow velocity, highly erodible silt loam, bare conditions with no protective cover, and high-intensity rain events.

Question 19: What is required in inspection reports?

Expense receipts
Site conditions and BMP status (Correct answer)
Soil samples
Personal notes

Correct answer: Site conditions and BMP status

Inspection reports are required to include detailed information on site conditions and the status of Best Management Practices (BMPs). This includes observations about erosion, sediment accumulation, and pollutant sources, alongside assessments of whether BMPs are properly installed, maintained, and functioning effectively. This comprehensive reporting ensures accountability and guides necessary corrective actions.

Question 20: During a site walk, an inspector observes a whitish crust on the soil surface in a low-lying area. This is most likely an indication of:

Calcium from decomposing vegetation
Fungal growth indicating good organic matter
Salt accumulation (efflorescence) from high soil sodicity or evaporation of mineralized water (Correct answer)
Lime applied as a soil amendment

Correct answer: Salt accumulation (efflorescence) from high soil sodicity or evaporation of mineralized water

White salt crusts on soil surfaces indicate high sodium or other soluble salt concentrations, which can cause soil dispersion and impede vegetation establishment.

Question 21: Which of the following best describes an 'operator' as defined under NPDES construction stormwater regulations?

Any subcontractor performing earthwork activities on the project
The licensed engineer who stamps the SWPPP drawings
Any entity with operational control over daily activities or the ability to modify plans/specifications (Correct answer)
The municipality issuing the grading permit for the project

Correct answer: Any entity with operational control over daily activities or the ability to modify plans/specifications

An 'operator' is any entity that has operational control over construction activities or control over the project's plans and specifications.

Question 22: Which of the following situations would trigger a mandatory amendment to the site's SWPPP?

A forecast for a large storm event expected next week.
The replacement of a damaged silt fence with a new one of the same type in the same location.
The project manager decides to re-route a primary haul road and create a new 2-acre staging area. (Correct answer)
A routine weekly inspection identifies that a wattle needs minor maintenance.

Correct answer: The project manager decides to re-route a primary haul road and create a new 2-acre staging area.

SWPPPs are considered living documents and must be amended whenever there are changes in design, construction, operation, or maintenance that have a significant effect on the potential for the discharge of pollutants. Re-routing a haul road and adding a large new staging area fundamentally changes the site's drainage, potential pollutant sources, and necessary controls, thus requiring a SWPPP amendment.

Question 23: Why are permeable pavements beneficial?

Resist evaporation
Enable infiltration (Correct answer)
Crack under pressure
Block water

Correct answer: Enable infiltration

Permeable pavements are designed with porous surfaces that allow stormwater to filter through them and infiltrate into the underlying soil, rather than running off the surface. This process helps to reduce stormwater runoff volume, replenish groundwater, and filter out pollutants. By enabling infiltration, permeable pavements mitigate flooding and improve water quality.

Question 24: Which federal agency has primary enforcement authority for NPDES violations at construction sites in states without authorized NPDES programs?

Federal Emergency Management Agency (FEMA)
U.S. Environmental Protection Agency (EPA) (Correct answer)
U.S. Army Corps of Engineers
U.S. Department of Agriculture Natural Resources Conservation Service

Correct answer: U.S. Environmental Protection Agency (EPA)

EPA retains direct NPDES enforcement authority in states that have not received EPA authorization to administer their own permit programs.

Question 25: Permeable pavement is classified as which type of Low Impact Development (LID) stormwater practice?

Slope stabilization BMP
Sediment trapping BMP
Conveyance BMP
Volume reduction / green infrastructure BMP (Correct answer)

Correct answer: Volume reduction / green infrastructure BMP

Permeable pavement allows runoff to infiltrate through the surface into a gravel reservoir below, reducing total runoff volume — the defining characteristic of a green infrastructure/LID approach.

Question 26: A construction SWPPP must be updated when which of the following occurs?

A new subcontractor begins work on site
The general contractor changes project managers
Site conditions change in a way that affects stormwater discharges (Correct answer)
Monthly rainfall totals exceed the seasonal average

Correct answer: Site conditions change in a way that affects stormwater discharges

NPDES Construction General Permits require SWPPP amendments whenever there are changes in design, construction, operation, or maintenance that affect the potential for pollutant discharges.

Question 27: What does the term 'common plan of development' mean in the context of SWPPP and permit coverage requirements?

A state-approved SWPPP template
A permit that covers multiple operators under one document
A shared BMP design used by neighboring sites
Any contiguous area where multiple construction activities will occur under a single plan (Correct answer)

Correct answer: Any contiguous area where multiple construction activities will occur under a single plan

A 'common plan of development' is a contiguous area planned for construction activities, and all disturbance within it is aggregated to determine permit applicability.

Question 28: How does vegetative cover reduce erosion compared to bare soil?

Vegetation intercepts rainfall, reduces surface sealing, and anchors soil with roots (Correct answer)
Vegetation increases soil compaction, limiting infiltration and runoff
Vegetation shades the soil, reducing evaporation but not erosion
Vegetation increases runoff velocity, moving sediment away from the site faster

Correct answer: Vegetation intercepts rainfall, reduces surface sealing, and anchors soil with roots

Vegetation reduces erosion through multiple mechanisms: canopy interception dissipates raindrop energy, roots bind soil particles, and leaf litter maintains infiltration rates.

Question 29: Which record type is used to document that a contractor received and understood the SWPPP requirements before beginning earth disturbance?

Subcontractor acknowledgment form or training record (Correct answer)
Hazardous materials manifest
Daily rainfall log
Notice of Intent (NOI)

Correct answer: Subcontractor acknowledgment form or training record

Subcontractor acknowledgment forms (or training records) document that workers responsible for BMP installation and maintenance have been informed of SWPPP requirements before disturbing soil.

Question 30: Under the EPA Construction General Permit, which of the following pollutants from construction sites requires specific BMP controls beyond sediment?

Carbon dioxide from equipment exhaust
Dust from unpaved access roads in arid regions
Concrete washout, paint, and fuel stored on site (Correct answer)
Noise from grading equipment

Correct answer: Concrete washout, paint, and fuel stored on site

The CGP requires BMPs to address non-sediment pollutants including concrete washout, fuels, oils, paints, and other chemicals stored or used on site.

Question 31: A state requires that construction sites implement post-construction stormwater controls as a condition of local land development approval. This requirement is most directly associated with which federal mandate?

Section 404 wetland mitigation banking regulations
The Endangered Species Act Section 7 consultation requirements
The National Environmental Policy Act (NEPA) environmental review process
NPDES Phase II stormwater rules requiring local MS4 programs to include post-construction standards (Correct answer)

Correct answer: NPDES Phase II stormwater rules requiring local MS4 programs to include post-construction standards

Phase II NPDES rules require Municipal Separate Storm Sewer System (MS4) programs to establish post-construction stormwater management standards for new development.

Question 32: Which soil characteristic most directly determines whether a soil is classified as cohesive or non-cohesive?

Grain size distribution
Clay mineral content and plasticity (Correct answer)
Organic matter percentage
Bulk density

Correct answer: Clay mineral content and plasticity

Cohesion in soils results from clay minerals and their plasticity; higher clay mineral content and plasticity index indicate greater inter-particle cohesion.

Question 33: A contractor installs a concrete washout area on-site without any liner. Which regulatory concern does this most directly trigger?

Violation of OSHA hazard communication standards
Violation of local solid waste disposal ordinances only
Potential unpermitted discharge of pH-elevated wastewater to stormwater (Correct answer)
Noncompliance with FEMA floodplain development regulations

Correct answer: Potential unpermitted discharge of pH-elevated wastewater to stormwater

Unlined concrete washouts can leach alkaline wastewater into stormwater, constituting an unpermitted pollutant discharge under NPDES.

Question 34: Permeable pavement systems reduce stormwater runoff volume primarily by:

Increasing surface slope to accelerate drainage
Allowing water to infiltrate through voids into underlying storage layers (Correct answer)
Reducing impervious area calculations by 50% by default
Directing runoff to adjacent vegetated swales only

Correct answer: Allowing water to infiltrate through voids into underlying storage layers

Permeable pavement contains open-graded voids that allow rainfall to pass through the surface and into a stone reservoir base, where it infiltrates into the subgrade or is slowly released.

Question 35: Which outlet structure configuration is best suited to control two separate design storms (e.g., 2-year and 100-year) from a single detention basin?

Single orifice plate
Perforated riser pipe
Riser with multiple orifices at different elevations (Correct answer)
Simple overflow weir

Correct answer: Riser with multiple orifices at different elevations

A multi-stage riser with orifices at different elevations independently controls smaller, more frequent storms at lower stages and larger storms at higher stages.

Question 36: Street sweeping of public roads adjacent to a construction site is primarily performed to address which stormwater pollution concern?

Reduce vehicle noise from heavy construction truck traffic on roadways
Prevent pavement damage caused by excessive weight of sediment deposits
Remove tracked sediment and debris before it is washed into storm drains by rain (Correct answer)
Improve site visibility for construction personnel operating heavy equipment

Correct answer: Remove tracked sediment and debris before it is washed into storm drains by rain

Street sweeping removes sediment tracked from construction sites onto public roads before rainfall events can mobilize that material into storm drains and downstream waterways.

Question 37: When documenting inspection findings, which practice best supports clear communication with all stakeholders?

Keep records vague to avoid legal liability
Only photograph items that are compliant
Use clear, factual language with specific locations and measurements avoiding subjective terms (Correct answer)
Use technical jargon to demonstrate expertise

Correct answer: Use clear, factual language with specific locations and measurements avoiding subjective terms

Factual, specific, and measurable language with location references ensures inspection reports are defensible and actionable for all parties.

Question 38: A constructed stormwater wetland differs from a wet retention pond primarily in that it:

Is only used for flood control and not water quality
Relies entirely on chemical precipitation to remove pollutants
Is designed with shallow marshy areas and emergent vegetation to enhance biological pollutant treatment (Correct answer)
Has no permanent water pool

Correct answer: Is designed with shallow marshy areas and emergent vegetation to enhance biological pollutant treatment

Constructed stormwater wetlands incorporate shallow wetland zones with emergent plants (cattails, bulrush) that provide biological nutrient uptake, microbial decomposition, and additional sediment trapping beyond what a pond alone can achieve.

Question 39: In which scenario is a rock berm PREFERABLE to a silt fence for sediment control?

Sheet flow over flat slopes less than 1%
Perimeter control along property lines
Concentrated flow conditions or in drainage channels (Correct answer)
Areas with established vegetation nearby

Correct answer: Concentrated flow conditions or in drainage channels

Rock berms can handle concentrated flow and higher flow velocities that would overwhelm and breach a silt fence, making them more appropriate for drainage channels.

Question 40: Which inspection frequency is typically required for sediment control BMPs during a period of active construction?

Once per month regardless of weather
After every rainfall event of 0.5 inches or more, and at least weekly (Correct answer)
Only after storm events exceeding the 10-year design storm
Before the start of each work week only

Correct answer: After every rainfall event of 0.5 inches or more, and at least weekly

Most NPDES construction general permits require BMP inspections after any storm event producing 0.5 inches or more of rainfall and at least once per week during active construction.

Question 41: Under many MS4 (Municipal Separate Storm Sewer System) permits, what is the purpose of requiring a Stormwater Pollution Prevention Plan (SWPPP) for post-construction activities?

To replace the need for any physical BMPs on the site
To document long-term maintenance responsibilities, inspection schedules, and ownership of post-construction BMPs (Correct answer)
To satisfy OSHA safety requirements for the construction crew
To provide proof of final stabilization to the local government

Correct answer: To document long-term maintenance responsibilities, inspection schedules, and ownership of post-construction BMPs

Post-construction SWPPPs or equivalent O&M agreements create a legally binding record of who is responsible for maintaining BMPs and how often inspections and maintenance must be performed.

Question 42: What does the letter 'D' represent in NRCS Hydrologic Soil Group (HSG) classification?

Slow infiltration rate
High infiltration rate
Very high infiltration rate
Very slow infiltration rate — highest runoff potential (Correct answer)

Correct answer: Very slow infiltration rate — highest runoff potential

HSG D soils have very slow infiltration rates (typically clay-rich or shallow over impervious layers) and generate the highest surface runoff.

Question 43: During a site inspection, a 15-gallon drum of hydraulic fluid is tipped over, and the entire contents spill onto a gravel staging area. The spill is quickly contained with absorbent materials. According to typical SWPPP requirements, what is the inspector's most important documentation responsibility?

Take a sample of the contaminated gravel for laboratory analysis.
Estimate the cost of the spilled material for the project manager.
Ensure the incident is recorded in the SWPPP's spill log with details on the substance, volume, location, and cleanup measures. (Correct answer)
Interview the equipment operator who caused the spill and include their statement in the report.

Correct answer: Ensure the incident is recorded in the SWPPP's spill log with details on the substance, volume, location, and cleanup measures.

The SWPPP requires tracking and reporting of spills. Documenting the specifics of the spill—what it was, how much, where it happened, and the response taken—in a dedicated spill log is a critical record-keeping requirement for compliance and future prevention efforts.

Question 44: A contractor disputes the inspector's finding that a turbidity barrier is non-functional. What is the most professionally appropriate response?

Allow the contractor to override the finding verbally
Document the disagreement in the inspection record, provide objective evidence (photos, measurements), and refer to permit standards (Correct answer)
Physically demonstrate the barrier's failure yourself
Withdraw the finding to avoid conflict

Correct answer: Document the disagreement in the inspection record, provide objective evidence (photos, measurements), and refer to permit standards

Professional dispute resolution requires maintaining the documented finding supported by objective evidence and referring disagreements to the regulatory standard, not personal opinion.

Question 45: During a site inspection, you observe vehicle maintenance being performed on bare soil near a drainage channel. Which pollution prevention concern is MOST significant?

Excessive noise from engine operations near residential areas
Potential petroleum product spills contaminating stormwater runoff (Correct answer)
Increased dust generation from vehicle movement on unpaved surfaces
Risk of workers slipping on wet soil during maintenance activities

Correct answer: Potential petroleum product spills contaminating stormwater runoff

Vehicle maintenance on bare soil near drainage channels creates a direct pathway for petroleum products (oil, hydraulic fluid, fuel) to enter stormwater conveyances and downstream water bodies.

Question 46: A CESSWI inspector discovers a confined space (e.g., a sediment basin outlet vault) that must be inspected. What is the required approach?

Enter quickly and exit quickly to minimize exposure
Skip the inspection and note it as inaccessible
Follow confined space entry procedures including atmospheric testing and a standby person (Correct answer)
Use a flashlight and enter alone if the space appears clear

Correct answer: Follow confined space entry procedures including atmospheric testing and a standby person

Permit-required confined spaces demand atmospheric testing, ventilation, a standby attendant, and an entry permit before any inspector enters.

Question 47: When a SWPPP is revised to add a new sediment basin, the revision must be signed by:

The original engineer who prepared the SWPPP
Any site employee who witnessed the change
The local municipality's inspector
A responsible corporate officer or duly authorized representative (Correct answer)

Correct answer: A responsible corporate officer or duly authorized representative

NPDES regulations require that SWPPP amendments be certified and signed by a responsible corporate officer or authorized representative of the permittee.

Question 48: Which factor most directly determines the settling velocity of a sediment particle in a quiescent (still) water environment?

Particle size, density, and shape (Correct answer)
Upstream travel distance before entering the basin
Particle moisture content at the time of erosion
Particle color and mineralogy

Correct answer: Particle size, density, and shape

Settling velocity in still water is governed by Stokes' Law, which relates particle diameter, density, and shape to the rate at which a particle sinks.

Question 49: When an inspector uses photographic documentation, what information should accompany each photo in the inspection record?

Only the file name generated by the camera
The inspector's personal opinion of the BMP's effectiveness
The contractor's name only
Date, time, location (station or GPS), subject description, and direction of view (Correct answer)

Correct answer: Date, time, location (station or GPS), subject description, and direction of view

Each photo should be accompanied by date, time, specific location, description of what is depicted, and viewing direction to be useful in enforcement or legal proceedings.

Question 50: What is the role of an Erosion and Sediment Control (ESC) plan in the context of regulatory compliance for construction projects?

It replaces the SWPPP and satisfies all NPDES permit conditions
It documents site-specific BMPs for controlling erosion and sediment, often required by local ordinance and incorporated into the SWPPP (Correct answer)
It must be prepared exclusively by a licensed geotechnical engineer
It is only required for projects disturbing more than 50 acres under federal law

Correct answer: It documents site-specific BMPs for controlling erosion and sediment, often required by local ordinance and incorporated into the SWPPP

ESC plans document erosion and sediment control measures required by local authorities and are typically incorporated as part of the site's SWPPP.

Question 51: What is the primary goal of a site inspection?

Check for graffiti
Measure noise levels
Verify BMPs and compliance (Correct answer)
Trim grass

Correct answer: Verify BMPs and compliance

The primary goal of a stormwater site inspection is to verify that Best Management Practices (BMPs) are correctly installed, maintained, and functioning as intended. Inspectors also ensure that the site is in compliance with all applicable stormwater permits and regulations. This proactive approach helps prevent pollution and protect water quality.

Question 52: According to SWPPP requirements, how soon after rain events must a CESSWI-level inspection of erosion controls be conducted?

Only after rain events exceeding 1 inch
Within 72 hours after any measurable precipitation
Once per week regardless of rain events
Within 24 hours after a 0.25-inch or greater rain event (Correct answer)

Correct answer: Within 24 hours after a 0.25-inch or greater rain event

Most Construction General Permits require inspection within 24 hours following a qualifying storm event (typically ≥0.25 inch) to assess BMP performance.

Question 53: What is the primary purpose of a Stormwater Pollution Prevention Plan (SWPPP) under the Construction General Permit?

To satisfy local zoning and land-use approval requirements
To estimate project costs for erosion control materials
To document BMPs and site conditions to prevent pollutant discharge (Correct answer)
To calculate the peak discharge rate for drainage design

Correct answer: To document BMPs and site conditions to prevent pollutant discharge

A SWPPP identifies BMPs and site-specific measures to prevent stormwater pollution from reaching waters of the United States.

Question 54: A site inspection reveals that silt fence posts are leaning at more than 30 degrees from vertical after a storm. The CORRECT corrective action is:

Remove accumulated sediment, pull posts back to vertical, and re-drive or replace (Correct answer)
Leave the fence in place until the end of construction season
Drive additional posts immediately downslope to brace the leaning posts
Add wire backing to support the leaning posts

Correct answer: Remove accumulated sediment, pull posts back to vertical, and re-drive or replace

Leaning posts indicate overloading from sediment accumulation or hydrostatic pressure; the proper fix is to remove sediment and restore the fence to its original installed position.

Question 55: What does 'good housekeeping' mean in the context of NPDES stormwater permits for construction sites?

Sweeping only interior building floors to prevent dust generation during dry weather
Implementing routine operational practices that minimize pollutant sources and pathways to stormwater (Correct answer)
Keeping construction tools cleaned and stored in locked containers after each shift
Maintaining clean and organized office trailers and break rooms for worker morale

Correct answer: Implementing routine operational practices that minimize pollutant sources and pathways to stormwater

In the NPDES stormwater context, good housekeeping refers to operational practices — proper storage, waste management, spill prevention, and material handling — that reduce the potential for pollutants to contact and enter stormwater runoff.

Question 56: What role does the 'corrective action log' play in SWPPP management?

It tracks daily equipment maintenance records
It records changes to the permit fee schedule
It serves as the official notice of permit termination
It documents deficiencies found during inspections, required repairs, responsible parties, and completion dates (Correct answer)

Correct answer: It documents deficiencies found during inspections, required repairs, responsible parties, and completion dates

The corrective action log creates an auditable record of identified deficiencies, the actions required to correct them, and confirmation that repairs were completed within required timeframes.

Question 57: An inspector notes turbid stormwater leaving a site but cannot measure turbidity on-site. Which documentation approach is MOST appropriate?

Record a qualitative visual description using standard color/clarity descriptors (Correct answer)
Leave a blank field in the report until lab results arrive
Delay the inspection report until portable equipment is obtained
Estimate turbidity as 'zero' since no equipment is available

Correct answer: Record a qualitative visual description using standard color/clarity descriptors

When quantitative measurement is not possible, inspectors should document qualitative visual observations using accepted descriptors (clear, light brown, chocolate brown, etc.) so that a record of conditions still exists.

Question 58: Which sediment control BMP is MOST appropriate for protecting a storm drain inlet in a paved parking lot during active construction?

Inlet protection filter bag or sediment trap (Correct answer)
Rock check dam
Silt fence staked around the inlet
Straw wattle placed 10 feet upstream

Correct answer: Inlet protection filter bag or sediment trap

Filter bags or inlet sediment traps are specifically designed to fit over or around paved inlet grates, capturing sediment while allowing drainage.

Question 59: When installing a rock check dam, what is the recommended height-to-width ratio for the notch or spillway?

The notch depth should be 1/3 the dam height and centered
There is no notch; water overtops uniformly
The notch should be 6 inches below the top of the dam edges (Correct answer)
The notch should be at the same elevation as the top of the dam

Correct answer: The notch should be 6 inches below the top of the dam edges

The spillway notch in a rock check dam is typically cut 6 inches below the top edges so that design flow passes through the notch while preventing flanking around the sides.

Question 60: The Universal Soil Loss Equation (USLE) factor 'K' represents what soil property?

Slope steepness
Crop management
Conservation practice
Soil erodibility (Correct answer)

Correct answer: Soil erodibility

The K factor in USLE quantifies a soil's susceptibility to detachment and transport by rainfall and runoff, based on texture, organic matter, and permeability.

Question 61: What does the term 'qualified personnel' mean in the context of SWPPP inspections?

A licensed professional engineer only
Anyone employed by the construction company
Any state employee
Someone with sufficient training, experience, and knowledge to identify erosion and sediment control deficiencies and implement corrective actions (Correct answer)

Correct answer: Someone with sufficient training, experience, and knowledge to identify erosion and sediment control deficiencies and implement corrective actions

Most permits define qualified personnel as someone with training and knowledge to assess BMPs and identify deficiencies, not necessarily a licensed PE.

Question 62: In the context of post-construction stormwater management, what does 'hydromodification' refer to?

The installation of stormwater infrastructure modifications after construction
The process of adding chemical treatment to stormwater
Changes in the natural hydrologic cycle (peak flows, runoff volume, duration) caused by land development (Correct answer)
Modifying a hydrograph by adding riprap

Correct answer: Changes in the natural hydrologic cycle (peak flows, runoff volume, duration) caused by land development

Hydromodification describes how impervious surfaces and altered drainage increase peak flows, total runoff volume, and flow duration compared to pre-development conditions, degrading stream channels.

Question 63: Under the NPDES Construction General Permit, what minimum rainfall threshold typically triggers the requirement to inspect a construction site for BMPs?

0.10 inch
0.50 inch
1.00 inch
0.25 inch (Correct answer)

Correct answer: 0.25 inch

Most NPDES Construction General Permits require post-storm inspections following rainfall events of 0.25 inch or greater within a 24-hour period.

Question 64: When performing a post-construction stormwater inspection, which document should the inspector reference to verify that BMPs were installed as approved?

The contractor's bid schedule
The approved stormwater management plan and construction drawings (Correct answer)
The local zoning ordinance
The NPDES Phase I permit

Correct answer: The approved stormwater management plan and construction drawings

The approved stormwater management plan and associated construction drawings define the required BMP types, sizes, locations, and specifications that the inspector verifies against field conditions.

Question 65: When a construction project is complete and all areas are stabilized, what must the permit holder file to terminate NPDES permit coverage?

A Notice of Intent (NOI) amendment
A Final Inspection Report
A Certificate of Occupancy
A Notice of Termination (NOT) (Correct answer)

Correct answer: A Notice of Termination (NOT)

A Notice of Termination (NOT) is submitted to the permitting authority once the site is stabilized and permit coverage is no longer needed.

Question 66: A CESSWI inspector reviewing site records finds that corrective actions identified in a previous inspection were not implemented within the required timeframe. How should this be documented?

The prior inspection record should be amended to remove the uncorrected finding
A new inspection report should note the repeat finding and the failure to correct within the required period (Correct answer)
The site should automatically be issued a stop-work order by the inspector
The inspector should verbally notify the operator and take no further action

Correct answer: A new inspection report should note the repeat finding and the failure to correct within the required period

Repeat or unresolved findings must be documented in subsequent inspection reports as ongoing violations, creating an accurate compliance record.

Question 67: What is the primary purpose of a level spreader at the outlet of a stormwater conveyance system?

Convert concentrated flow to sheet flow (Correct answer)
Store runoff during peak events
Filter sediment from runoff
Increase flow velocity to prevent sedimentation

Correct answer: Convert concentrated flow to sheet flow

A level spreader converts concentrated pipe or channel flow into diffuse sheet flow, reducing erosive velocities before runoff enters a vegetated buffer.

Question 68: Which stormwater practice provides the greatest co-benefit of groundwater recharge in addition to runoff volume reduction?

Green roof
Wet detention pond
Extended detention basin
Infiltration-based BMP (trench, basin, or permeable pavement) (Correct answer)

Correct answer: Infiltration-based BMP (trench, basin, or permeable pavement)

Infiltration-based BMPs direct stormwater into the soil profile, directly recharging groundwater and sustaining baseflows in receiving streams, unlike detention or rooftop practices.

Question 69: A construction site experiences a severe rain event that causes sediment to discharge into an adjacent stream. Under NPDES permit conditions, what is the operator's immediate obligation?

Submit a Notice of Termination for the permit
Transfer permit responsibility to the general contractor
Remove all BMPs and start fresh with a revised SWPPP
Document the event and notify the permitting authority within the required timeframe (Correct answer)

Correct answer: Document the event and notify the permitting authority within the required timeframe

NPDES permits typically require operators to document unauthorized discharges and report them to the permitting authority within a specified timeframe (often 24–72 hours).

Question 70: An inspector notices that a construction site's stabilized construction entrance is tracked out onto a public road. What is the correct immediate response?

Issue a stop-work order for the entire site
Document the condition and schedule a follow-up inspection in 30 days
Require the contractor to install a second construction entrance
Require immediate road sweeping or washing of tracked sediment and improvement of the entrance BMP (Correct answer)

Correct answer: Require immediate road sweeping or washing of tracked sediment and improvement of the entrance BMP

Tracked sediment on public roads must be removed immediately to prevent it from washing into storm drains, and the entrance BMP must be improved to prevent recurrence.

Question 71: A CESSWI inspector identifies a BMP deficiency during an inspection. The timeframe for corrective action under most construction general permits is typically:

Within 7 calendar days for most deficiencies, with some requiring immediate action for active discharges (Correct answer)
Immediately (within hours) for all deficiencies regardless of severity
Within 90 days to allow contractor scheduling
At the end of the construction project

Correct answer: Within 7 calendar days for most deficiencies, with some requiring immediate action for active discharges

Most CGPs require non-emergency deficiencies to be corrected within 7 calendar days, while active discharges or high-risk conditions may require immediate action.

Question 72: Under the EPA's MS4 (Municipal Separate Storm Sewer System) permit program, which minimum control measure specifically addresses post-construction stormwater management?

MCM 1 – Public Education and Outreach
MCM 5 – Post-Construction Stormwater Management in New Development and Redevelopment (Correct answer)
MCM 6 – Pollution Prevention/Good Housekeeping
MCM 3 – Illicit Discharge Detection and Elimination

Correct answer: MCM 5 – Post-Construction Stormwater Management in New Development and Redevelopment

MCM 5 requires MS4 permittees to develop and enforce programs to address stormwater from new development and redevelopment projects that disturb one or more acres.

Question 73: During a site inspection, you observe sediment deposited outside the construction boundary. This MOST likely indicates:

Failure or inadequacy of perimeter sediment controls (Correct answer)
Normal sediment redistribution from wind activity
Sediment transport from adjacent undisturbed areas
Sediment from vehicle tracking on public roads

Correct answer: Failure or inadequacy of perimeter sediment controls

Sediment deposited beyond the construction limit of disturbance is direct evidence that perimeter BMPs have failed to contain site runoff.

Question 74: During a routine inspection, an inspector discovers that a subcontractor is operating without being listed on the site's SWPPP. What is the appropriate corrective action?

Report the subcontractor to the state environmental agency
Require the subcontractor to obtain a separate NPDES permit
Issue a stop-work order to the subcontractor immediately
Add the subcontractor to the SWPPP and ensure they receive a copy of relevant sections (Correct answer)

Correct answer: Add the subcontractor to the SWPPP and ensure they receive a copy of relevant sections

All subcontractors performing earth-disturbing work must be identified in the SWPPP; the operator should update the plan and provide the subcontractor with applicable SWPPP requirements.

Question 75: What role do vegetated rooftops play?

Delay runoff and cool buildings (Correct answer)
Enhance signal strength
Trap wind
Increase erosion

Correct answer: Delay runoff and cool buildings

Vegetated rooftops, also known as green roofs, are designed to absorb rainfall, which delays the flow of stormwater runoff into drainage systems. The plants and soil also provide insulation and through evapotranspiration, they help cool the building and its surrounding environment. This reduces the urban heat island effect and lowers energy consumption for air conditioning.

Question 76: What distinguishes a sediment trap from a sediment basin in terms of drainage area?

Both can serve up to 10 acres; basin is used when depth exceeds 5 feet
Sediment traps serve areas less than 5 acres; basins are required for 5 acres or more (Correct answer)
Sediment traps serve areas less than 1 acre; basins are required for larger areas
There is no regulatory distinction; the terms are interchangeable

Correct answer: Sediment traps serve areas less than 5 acres; basins are required for 5 acres or more

Sediment traps are typically designed for drainage areas less than 5 acres, while sediment basins with engineered outlet structures are required for larger disturbed areas.

Question 77: Under the NPDES Construction General Permit, which condition triggers the requirement to implement 'non-storm water management' erosion controls?

Discharge of irrigation water or dewatering effluent from a construction site (Correct answer)
Rain events exceeding 0.5 inches in 24 hours
Disturbance of more than 5 acres at one time
Presence of endangered species habitat within 500 feet

Correct answer: Discharge of irrigation water or dewatering effluent from a construction site

Non-stormwater discharges such as irrigation water or construction dewatering effluent require specific management BMPs because they are not precipitation-generated.

Question 78: A construction project disturbs 0.8 acres. Under federal NPDES rules, is a permit required?

Yes, all earth disturbance requires a permit
No, only sites disturbing 1 acre or more require a permit (Correct answer)
Yes, but only if within 100 feet of a waterbody
No, permits are only required for sites over 5 acres

Correct answer: No, only sites disturbing 1 acre or more require a permit

Federal NPDES Construction General Permits apply to sites disturbing 1 acre or more of land, so a 0.8-acre project does not trigger the federal permit threshold.

Question 79: Which federal law establishes the framework for protecting wetlands adjacent to construction sites and requires mitigation for unavoidable impacts?

The Safe Drinking Water Act (SDWA)
The National Historic Preservation Act (NHPA)
The Clean Water Act Section 404 and associated regulatory guidance (Correct answer)
The Resource Conservation and Recovery Act (RCRA)

Correct answer: The Clean Water Act Section 404 and associated regulatory guidance

CWA Section 404 requires USACE permits for wetland fill and mandates mitigation (avoid, minimize, compensate) for unavoidable wetland impacts.

Question 80: A CESSWI inspector discovers that a permitted construction site is discharging turbid stormwater directly to a stream without functional BMPs. What is the most appropriate immediate action?

Document the violation, notify the site operator, and report to the permitting authority (Correct answer)
Contact FEMA to activate the National Flood Insurance Program
Issue an immediate stop-work order under federal authority
Require the contractor to halt all work until EPA provides written guidance

Correct answer: Document the violation, notify the site operator, and report to the permitting authority

Inspectors document noncompliance and notify operators and the regulatory authority; federal enforcement authority rests with the permitting agency, not the inspector.

Question 81: An inspector observes a rock check dam in a channel with a 4% grade. The crest of the downstream dam is at the same elevation as the toe of the upstream dam. Sediment has accumulated to approximately half the height of the downstream dam. What is the most appropriate action for the inspector to recommend?

Reconstruct the dam to be 12 inches lower in the center than at the edges.
Add another check dam between the existing ones to improve efficiency.
No action is needed as the check dam is functioning as designed.
Remove the accumulated sediment from the upstream side of the dam. (Correct answer)

Correct answer: Remove the accumulated sediment from the upstream side of the dam.

Regular maintenance is crucial for the effectiveness of check dams. Sediment should be removed when it accumulates to one-half of the dam's height to restore ponding capacity and prevent sediment from being washed downstream in subsequent storm events.

Question 82: When multiple operators share responsibility on a single construction site under a Construction General Permit, how is permit responsibility typically allocated?

The landowner always holds sole permit responsibility regardless of who performs work
Permit responsibility automatically transfers to whoever installs the sediment controls
Each operator with operational control over a portion of the site may need separate or co-permittee coverage (Correct answer)
Only the general contractor holds permit responsibility; subcontractors are exempt

Correct answer: Each operator with operational control over a portion of the site may need separate or co-permittee coverage

Operators with day-to-day operational control over site activities may each require permit coverage or be named as co-permittees.

Question 83: Under the EPA CGP, for how many years after permit termination must stormwater inspection records be retained?

1 year
2 years
5 years
3 years (Correct answer)

Correct answer: 3 years

The EPA CGP requires that all inspection records, SWPPPs, and supporting documents be retained for at least 3 years after permit termination.

Question 84: What is the primary goal of erosion control?

Minimize soil movement (Correct answer)
Grow vegetation
Increase runoff
Build roads

Correct answer: Minimize soil movement

The primary goal of erosion control is to prevent or reduce the displacement and transport of soil particles by wind or water. Uncontrolled erosion can lead to loss of fertile topsoil, sedimentation of waterways, and damage to infrastructure. By minimizing soil movement, erosion control measures protect natural resources and maintain site stability.

Question 85: Under Low Impact Development (LID) principles, what is the primary goal when managing stormwater from a new development?

Size detention basins to handle the 500-year storm
Pipe all runoff directly to the nearest water body
Mimic pre-development hydrology by managing runoff at the source (Correct answer)
Maximize impervious surface to reduce maintenance

Correct answer: Mimic pre-development hydrology by managing runoff at the source

LID aims to replicate pre-development hydrology through distributed, small-scale practices that promote infiltration, evapotranspiration, and retention close to where rain falls.

Question 86: A wattled straw roll is placed on a slope. Which orientation relative to the slope contours is CORRECT?

Parallel to the slope direction to channel water
Orientation does not affect performance
Perpendicular to the slope, along the contour (Correct answer)
At a 45-degree angle to maximize coverage

Correct answer: Perpendicular to the slope, along the contour

Straw wattles must be installed perpendicular to the slope (along the contour) to intercept sheet flow across the slope and allow sediment to settle behind the roll.

Question 87: What is the primary limitation of using straw mulch alone (without tackifier or netting) on slopes steeper than 3:1?

Straw promotes excessive weed growth on steep terrain
Straw decomposes too slowly on steep slopes
Straw will be displaced by wind and runoff velocity on steep slopes (Correct answer)
Straw has insufficient thickness to prevent raindrop impact

Correct answer: Straw will be displaced by wind and runoff velocity on steep slopes

On slopes steeper than 3:1, water velocity and wind forces exceed the stability of loose straw, requiring tackifier, netting, or blankets to hold mulch in place.

Question 88: Where should a concrete washout area be located on a construction site to prevent stormwater contamination?

Directly adjacent to the nearest storm drain inlet for easy drainage
Within 10 feet of the concrete mixing area regardless of drainage patterns
At least 50 feet from storm drains, streams, and other water bodies (Correct answer)
Upslope from all drainage channels to allow natural dilution

Correct answer: At least 50 feet from storm drains, streams, and other water bodies

Concrete washout areas must be sited at least 50 feet from storm drains, streams, and water bodies to prevent highly alkaline concrete wastewater from entering waterways.

Question 89: A CESSWI is conducting a site inspection and finds that a silt fence is sagging and has sediment accumulated to more than half its height. According to common compliance standards, what is the most appropriate immediate action?

Remove the silt fence as it is no longer effective.
Document the finding and schedule maintenance for the following week.
Document the deficiency and require that maintenance be performed promptly to restore its function. (Correct answer)
Note that the BMP is functioning as intended by capturing sediment.

Correct answer: Document the deficiency and require that maintenance be performed promptly to restore its function.

Best Management Practices (BMPs) like silt fences require regular maintenance to function correctly. A common rule of thumb is that sediment should be removed when it reaches one-third to one-half the height of the fence. A sagging fence with excessive accumulation is a failing BMP that needs to be documented as a deficiency requiring prompt corrective action.

Question 90: When documenting inspection findings, which information is LEAST critical to include in the inspection report?

Location and description of each BMP inspected
Inspector's name and qualifications
Date, time, and weather conditions
Names of all workers observed on site that day (Correct answer)

Correct answer: Names of all workers observed on site that day

Worker rosters are not a required component of inspection reports; the critical elements are inspector identity, site conditions, BMP status, and corrective actions.

Question 91: A SWPPP requires inspections every 7 days and within 24 hours after a 0.25-inch rain event. During a week with two qualifying rain events, the minimum number of required inspections is:

3 (Correct answer)
4
1
2

Correct answer: 3

The two post-storm inspections (within 24 hours of each event) satisfy the weekly requirement if they occur within the 7-day interval, resulting in a minimum of 2 inspections for that week.

Question 92: What does 'final stabilization' mean in the context of NPDES Construction General Permits?

The site has passed a final municipal inspection
All grading work is complete
Temporary BMPs have been removed from the site
A uniform perennial vegetative cover of 70% has been established, or equivalent stabilization measures are in place (Correct answer)

Correct answer: A uniform perennial vegetative cover of 70% has been established, or equivalent stabilization measures are in place

Final stabilization requires a uniform perennial vegetative cover with 70% density or equivalent non-vegetative measures over all disturbed areas with no potential for discharge.

Question 93: On a construction site soil report, a 'dispersion' problem refers to which condition?

Soil particles that resist compaction
Soil particles that deflocculate in water, making it highly erodible (Correct answer)
Soil that collapses suddenly when wetted
Soil with high organic matter content

Correct answer: Soil particles that deflocculate in water, making it highly erodible

Dispersive soils have clay particles that repel each other in water, causing the soil to erode internally (piping) or on the surface at very low shear stresses.

Question 94: Who is ultimately responsible for ensuring a SWPPP is properly implemented on a construction site?

The local municipality
The land owner or operator (Correct answer)
The state environmental agency
The erosion control contractor

Correct answer: The land owner or operator

Under NPDES permit requirements, the land owner or operator bears ultimate responsibility for SWPPP implementation and compliance.

Question 95: A lightning storm approaches while an inspector is in an open field near a detention pond. What is the safest immediate action?

Seek shelter in a substantial building or hard-topped vehicle immediately (Correct answer)
Crouch near the water's edge to lower elevation
Stand under the nearest tree for cover
Continue inspecting and work faster to finish

Correct answer: Seek shelter in a substantial building or hard-topped vehicle immediately

Lightning safety requires immediately seeking shelter in a substantial building or hard-topped metal vehicle, avoiding open areas, water, and trees.

Question 96: What does a Total Maximum Daily Load (TMDL) establish for an impaired water body?

The maximum volume of stormwater that can be discharged daily
The maximum amount of a pollutant a water body can receive and still meet water quality standards (Correct answer)
The minimum buffer distance required between construction and waterways
The required frequency of stormwater monitoring at construction sites

Correct answer: The maximum amount of a pollutant a water body can receive and still meet water quality standards

A TMDL sets the maximum pollutant load a water body can assimilate while still meeting applicable water quality standards.

Question 97: Under most state construction general permits, what is the maximum allowable turbidity or visual benchmark that inspectors use to evaluate whether a BMP is functioning effectively?

Discharge must not cause a discernible change in the color or clarity of the receiving water (Correct answer)
Discharge must be completely clear with zero suspended solids
Discharge turbidity must not exceed 5 NTU above background levels
Discharge must not cause a visible sheen, foam, or floating solids in receiving waters

Correct answer: Discharge must not cause a discernible change in the color or clarity of the receiving water

Many permits use narrative standards prohibiting discharges that cause a discernible change in color or clarity of receiving waters as the visual benchmark.

Question 98: Which of the following best describes the 'common plan of development or sale' concept as it applies to NPDES construction stormwater thresholds?

It applies only to commercial development projects, not residential construction
It aggregates contiguous or nearby parcels developed under a common plan to determine whether the 1-acre permit threshold is met (Correct answer)
It exempts residential subdivisions from NPDES requirements if individual lots are under 1 acre
It allows multiple small sites to share a single SWPPP if they are within 1 mile of each other

Correct answer: It aggregates contiguous or nearby parcels developed under a common plan to determine whether the 1-acre permit threshold is met

Related parcels developed under a common plan are aggregated to determine total disturbance area, even if individual phases are under 1 acre.

Question 99: Which of the following is NOT typically required to be included in a SWPPP?

Inspection and maintenance procedures for BMPs
Description of potential pollutant sources
Contractor's liability insurance certificate (Correct answer)
Site map showing drainage patterns and BMP locations

Correct answer: Contractor's liability insurance certificate

Insurance certificates are not a SWPPP regulatory requirement; the plan must address pollution prevention, not contractor finances.

Question 100: Which curve number (CN) value in the TR-55 method indicates the LEAST runoff potential from a given soil and land use combination?

85
98
35 (Correct answer)
70

Correct answer: 35

Lower curve numbers indicate greater infiltration and less runoff potential; a CN of 35 represents a highly permeable soil with dense vegetation, while 98 represents nearly impervious surfaces.

Question 101: A stormwater inspector finds that the emergency spillway of a detention pond has been blocked by debris. What is the primary risk this creates?

Accelerated eutrophication of the permanent pool
Potential for dam overtopping and embankment failure during extreme storms (Correct answer)
Reduced water quality treatment efficiency
Increased mosquito breeding habitat

Correct answer: Potential for dam overtopping and embankment failure during extreme storms

The emergency spillway protects the embankment from overtopping; if blocked, flows exceeding the principal outlet capacity could overtop and rapidly erode the embankment, leading to failure.

Certified Erosion, Sediment, and Storm Water Inspector (CESSWI) Exam

The CESSWI certification validates the knowledge and skills of professionals responsible for inspecting and ensuring compliance with erosion, sediment, and stormwater management regulations.

100

Questions

120 min

Time Limit

75%

To Pass

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