CEPSCI Certification Exam — Questions and Answers

Question 1: What is the hydraulic residence time of a sediment basin?

The duration of the design storm
The time it takes to install the basin
The average time water spends in the basin, which determines how much sediment can settle out (Correct answer)
The time between required cleanouts

Correct answer: The average time water spends in the basin, which determines how much sediment can settle out

Hydraulic residence time is the average time water spends in the basin, calculated as basin volume divided by flow rate; longer residence time allows more and finer particles to settle.

Question 2: The emergency spillway of a sediment basin is designed to:

Prevent all flow from leaving the basin
Safely pass flows from storms exceeding the design storm without causing basin failure (Correct answer)
Provide the normal discharge path
Filter sediment from large storm events

Correct answer: Safely pass flows from storms exceeding the design storm without causing basin failure

Emergency spillways safely convey overflows from storms exceeding the design capacity, preventing basin failure and uncontrolled breaching that could release stored sediment.

Question 3: If a construction inspector discovers that a site's stormwater discharge is causing a visible plume of sediment in a receiving stream, what is the FIRST action that should be taken?

File a formal complaint with the EPA regional office
Halt all construction work indefinitely until the plume clears
Install additional silt fence along the stream bank
Immediately notify the site operator and document the condition with photographs and written notes (Correct answer)

Correct answer: Immediately notify the site operator and document the condition with photographs and written notes

The first step is to notify the responsible operator and document the discharge condition thoroughly, as documentation is required for permit compliance and corrective action tracking.

Question 4: What is the effect of vegetative cover on soil erosion rates?

Vegetation only reduces erosion in dry climates
Vegetation increases erosion by loosening soil with roots
Vegetation dramatically reduces erosion by intercepting rainfall, binding soil with roots, and slowing runoff (Correct answer)
Vegetation has no significant effect on erosion

Correct answer: Vegetation dramatically reduces erosion by intercepting rainfall, binding soil with roots, and slowing runoff

A well-established vegetative cover can reduce erosion by more than 99% compared to bare soil by intercepting raindrop energy, increasing infiltration, and binding soil particles with roots.

Question 5: Which document should be reviewed first when assessing a site's erosion control requirements?

The equipment rental agreement
The construction budget
The local municipal separate storm sewer system (MS4) permit and local ordinances (Correct answer)
The architect's floor plan

Correct answer: The local municipal separate storm sewer system (MS4) permit and local ordinances

Local MS4 permits and ordinances establish the minimum requirements for erosion and sediment control that all construction sites within that jurisdiction must meet.

Question 6: Short-circuiting in a sediment basin means:

Sediment blocking the outlet pipe
An electrical problem with the outlet pump
Runoff flowing directly from inlet to outlet without adequate residence time for settling (Correct answer)
The basin overflowing during a storm

Correct answer: Runoff flowing directly from inlet to outlet without adequate residence time for settling

Short-circuiting occurs when flow channels directly from the inlet to the outlet, bypassing the settling zone and reducing residence time, which dramatically reduces sediment removal efficiency.

Question 7: Coir logs are most commonly used for:

Shoreline and streambank stabilization and as check dams in shallow swales (Correct answer)
Stabilizing sediment basin embankments
Constructing temporary access roads
Filtering water in sediment basins

Correct answer: Shoreline and streambank stabilization and as check dams in shallow swales

Coir logs are biodegradable rolls of coconut fiber used to stabilize streambanks, shorelines, and shallow swales, providing temporary structural support while vegetation establishes.

Question 8: What is the correct approach when a BMP is found to have failed or to be inadequate during an inspection?

Only act if the regulatory agency has been notified first
Document the failure and wait until the next scheduled maintenance cycle
Remove the failed BMP and leave the area unprotected
Repair or replace the BMP as soon as practicable, typically within a defined timeframe required by the permit (Correct answer)

Correct answer: Repair or replace the BMP as soon as practicable, typically within a defined timeframe required by the permit

Permits typically require prompt repair of failed BMPs, often within 24 hours or before the next rain event, to maintain continuous erosion and sediment control.

Question 9: Surface area is critical in sediment trap design because:

Only the outlet pipe size matters
Larger surface area allows more particles to settle per unit time by lowering the overflow rate (Correct answer)
Surface area should be ignored
Only depth matters for sediment trap design

Correct answer: Larger surface area allows more particles to settle per unit time by lowering the overflow rate

Surface area is the key design parameter for sediment settling because larger surface area relative to flow rate lowers the overflow rate and increases the proportion of particles that settle out.

Question 10: What unit of measurement is most commonly used to express turbidity in stormwater monitoring?

NTU (Correct answer)
ppm
CFU/100mL
mg/L

Correct answer: NTU

Nephelometric Turbidity Units (NTU) is the standard unit used to measure turbidity in water quality monitoring programs.

Question 11: Which particle size is the most difficult to remove in a sediment basin?

Coarse silt
Small gravel
Sand and gravel
Clay and fine silt particles (Correct answer)

Correct answer: Clay and fine silt particles

Clay and fine silt particles have very low settling velocities due to their small mass, requiring very long residence times or coagulation and flocculation treatment to be effectively removed.

Question 12: What is 'soil erodibility' as measured by the K factor in the USLE?

The susceptibility of soil to detachment and transport by rainfall and runoff (Correct answer)
The ability of soil to support plant growth
The ability of soil to resist compaction by heavy equipment
The drainage rate of soil under saturated conditions

Correct answer: The susceptibility of soil to detachment and transport by rainfall and runoff

The K factor quantifies how easily a specific soil type is detached by rainfall and transported by runoff, integrating texture, structure, organic matter, and permeability.

Question 13: Which condition would most increase the peak discharge from a construction site?

Compacting the soil and removing vegetation (Correct answer)
Increasing vegetation cover
Installing infiltration basins
Reducing the impervious area

Correct answer: Compacting the soil and removing vegetation

Compacting soil reduces infiltration capacity and removing vegetation eliminates interception and evapotranspiration, both of which increase the volume and rate of surface runoff.

Question 14: How does freeze-thaw cycling affect soil erodibility on construction sites?

Freeze-thaw cycles compact soil and reduce erosion
Freeze-thaw cycles have no effect on disturbed soils
Repeated freezing and thawing disrupts soil structure and increases erodibility by breaking up aggregates and leaving soil loose and vulnerable (Correct answer)
Freezing permanently stabilizes soil against erosion

Correct answer: Repeated freezing and thawing disrupts soil structure and increases erodibility by breaking up aggregates and leaving soil loose and vulnerable

As water in soil pores freezes and expands, it breaks apart soil aggregates; when the ice melts, the disturbed, loosened particles are highly vulnerable to erosion by rainfall and runoff.

Question 15: What is the primary goal of restoring native vegetation on a post-construction site?

To increase property values with ornamental plantings
To satisfy landscaping aesthetic requirements only
To establish a self-sustaining plant community that prevents erosion, supports biodiversity, and requires minimal long-term maintenance (Correct answer)
To provide shade for construction workers after the project is complete

Correct answer: To establish a self-sustaining plant community that prevents erosion, supports biodiversity, and requires minimal long-term maintenance

Native vegetation is adapted to local climate and soils, establishing deep roots and dense canopy that provide superior erosion control, habitat value, and reduced maintenance needs.

Question 16: Which of the following would not file a Notice of Intent (NOI) prior to any land-disturbing activities?

Compliance Inspector (Correct answer)
Primary Permittee
Utility Provider
Secondary Permittee

Correct answer: Compliance Inspector

Explanation: In the context of erosion and sediment control regulations, filing a Notice of Intent (NOI) is typically required by the primary permittee (such as a developer or contractor) before any land-disturbing activities commence. The NOI notifies regulatory authorities of the intent to implement erosion and sediment control measures in compliance with permit requirements. Compliance Inspectors do not file an NOI because their role is to ensure compliance with existing permits and regulations, not to initiate land-disturbing activities.

Question 17: What is the design storm typically used for sizing temporary sediment basins?

2-year or 10-year storm depending on jurisdiction (Correct answer)
1-year, 24-hour storm
100-year storm
50-year storm

Correct answer: 2-year or 10-year storm depending on jurisdiction

Many jurisdictions require temporary sediment basins to be sized for the 2-year or 10-year design storm, though specific requirements vary by state and local regulations.

Question 18: Which of the following best describes 'green infrastructure' in post-construction stormwater management?

Using only native plant materials in landscaping
Installing solar panels on buildings
Practices that use natural processes — such as infiltration, evapotranspiration, and filtration — to manage stormwater close to the source (Correct answer)
Using only recycled materials in construction

Correct answer: Practices that use natural processes — such as infiltration, evapotranspiration, and filtration — to manage stormwater close to the source

Green infrastructure mimics natural hydrologic processes to manage stormwater at the source, reducing runoff volume, peak flows, and pollutant loading to receiving waters.

Question 19: What is the purpose of riparian buffer zones in stormwater management?

To slow runoff, filter sediment and pollutants, and stabilize stream banks through vegetation (Correct answer)
To direct concentrated flow to streams
To provide material storage areas
To reduce vegetation near water bodies

Correct answer: To slow runoff, filter sediment and pollutants, and stabilize stream banks through vegetation

Riparian buffers use natural vegetation along waterways to slow runoff, filter pollutants and sediment, stabilize banks, and maintain water quality in adjacent streams.

Question 20: What level of rainfall typically triggers a required post-storm inspection under most NPDES Construction General Permits?

Any measurable rainfall
0.5 inches in a 24-hour period (Correct answer)
1.0 inch in a 24-hour period
0.25 inches in a 24-hour period

Correct answer: 0.5 inches in a 24-hour period

Most NPDES Construction General Permits require a post-storm inspection within 24 hours of a storm event producing 0.5 inches or more of rainfall.

Question 21: Which statement best describes the concept of nurse crops in revegetation?

Crops grown to feed construction workers
Plants used only in wetland restoration
Crops specifically grown for wildlife habitat
Fast-establishing temporary plants that protect and shelter slower-germinating permanent species during establishment (Correct answer)

Correct answer: Fast-establishing temporary plants that protect and shelter slower-germinating permanent species during establishment

Nurse crops are fast-establishing temporary plants that provide immediate cover and protection from erosion, wind, and temperature extremes while slower-growing permanent species establish.

Question 22: Which condition makes soils most susceptible to erosion during construction?

Bare, freshly disturbed soils with no vegetative cover on slopes during high-intensity rainfall (Correct answer)
Compacted, sealed soils with low permeability
Soils covered with 4 inches of straw mulch
Soils that are moist but not saturated, with established vegetation

Correct answer: Bare, freshly disturbed soils with no vegetative cover on slopes during high-intensity rainfall

Disturbed soils lack protective vegetation and aggregate structure, making them extremely vulnerable to raindrop impact and runoff — conditions that are precisely what construction creates.

Question 23: To whom are NPDES permits typically issued?

Environmental consultants conducting site assessments.
Operators or companies responsible for a specific discharge. (Correct answer)
Regulatory agencies overseeing construction projects.
Homeowners managing stormwater runoff.

Correct answer: Operators or companies responsible for a specific discharge.

Explanation: NPDES (National Pollutant Discharge Elimination System) permits are issued to operators or companies responsible for a particular discharge of pollutants into the waters of the United States. These permits are regulated by the Environmental Protection Agency (EPA) or delegated state agencies and outline specific discharge limits, monitoring requirements, and other conditions to ensure compliance with water quality standards and environmental regulations.

Question 24: The RUSLE factor 'K' represents:

Soil erodibility (Correct answer)
Rainfall erosivity
Slope length and steepness
Cover-management factor

Correct answer: Soil erodibility

The K factor in RUSLE represents soil erodibility, quantifying a soil's susceptibility to detachment and transport by rainfall and runoff.

Question 25: A bioswale differs from a conventional drainage swale primarily because it:

Carries only clean water
Is only used in arid climates
Is lined with concrete to prevent erosion
Uses engineered soil and vegetation to filter and infiltrate runoff while conveying it (Correct answer)

Correct answer: Uses engineered soil and vegetation to filter and infiltrate runoff while conveying it

A bioswale uses engineered soil media and dense vegetation to filter pollutants and promote infiltration as runoff flows through it, providing water quality benefits beyond simple conveyance.

Question 26: What does it mean to daylight a drainage pipe on a slope?

Install the pipe above the soil surface only
Paint the pipe for visibility
Bring the pipe outlet to the surface at the base of the slope, requiring outlet protection to prevent scour (Correct answer)
Run the pipe vertically

Correct answer: Bring the pipe outlet to the surface at the base of the slope, requiring outlet protection to prevent scour

Daylighting a pipe means bringing its outlet to the surface, typically at the base of a slope, where outlet protection such as riprap must be installed to dissipate energy and prevent scour.

Question 27: What is the function of an 'extended detention basin' in post-construction stormwater management?

To provide a permanent water feature for the development
To temporarily store stormwater and release it slowly over 24–48 hours, allowing sediment to settle and reducing downstream peak flows (Correct answer)
To permanently store all stormwater runoff from the site
To eliminate the need for any other post-construction BMPs

Correct answer: To temporarily store stormwater and release it slowly over 24–48 hours, allowing sediment to settle and reducing downstream peak flows

Extended detention basins attenuate peak flows and promote sediment settling by holding runoff for an extended period before slowly releasing it through a low-flow outlet.

Question 28: PAM is a chemical that is added to turbulent runoff primarily to achieve the following.

Cause flocculation that reduces sediment transport. (Correct answer)
Provide binding of seed to mulch so that vegetation can be established.
Change the turbulent flow to laminar flow.
Make the water potable immediately.

Correct answer: Cause flocculation that reduces sediment transport.

Explanation: PAM (Polyacrylamide) is a chemical used in erosion and sediment control practices, particularly in controlling sediment in runoff from construction sites or disturbed areas. When added to turbulent runoff water, PAM functions by causing flocculation. Flocculation is the process where small particles in the water aggregate together to form larger particles (called flocs). These flocs are heavier and settle out more readily than individual particles, reducing the turbidity of the water and hence reducing sediment transport. This process helps to clarify the water by promoting the settling of suspended solids, which can then be trapped or filtered out more effectively by sediment control measures such as silt fences or sediment basins.

Question 29: How does the slope length factor (L) in the USLE affect predicted soil loss?

Longer slopes always have less erosion than shorter slopes
Shorter slopes have higher erosion rates because water moves faster on them
Slope length has no effect on erosion calculations
Longer slopes allow more runoff to accumulate and accelerate, increasing erosive power and predicted soil loss (Correct answer)

Correct answer: Longer slopes allow more runoff to accumulate and accelerate, increasing erosive power and predicted soil loss

As runoff travels down a longer slope, it accumulates more volume and velocity, increasing its erosive energy and the quantity of sediment it can transport.

Question 30: A check dam installed in a swale is primarily designed to:

Mark the boundary of the site
Direct water to storm drains
Prevent vehicle access
Reduce flow velocity and promote sediment settling in the channel (Correct answer)

Correct answer: Reduce flow velocity and promote sediment settling in the channel

Check dams reduce the velocity of flow in drainage channels and swales, promoting sediment deposition and reducing the channel's erosive energy.

Question 31: What is the primary function of temporary seeding on a construction site?

To attract wildlife to the site
To establish the permanent landscape
To improve the aesthetic appearance of the site
To provide rapid vegetative cover that stabilizes exposed soil and reduces erosion during construction (Correct answer)

Correct answer: To provide rapid vegetative cover that stabilizes exposed soil and reduces erosion during construction

Temporary seeding provides a fast-growing vegetative cover on exposed soils to reduce erosion during construction activities, even though the vegetation will eventually be replaced with permanent cover.

Question 32: What straw mulch application rate is typically recommended to achieve approximately 75% soil cover?

500 pounds per acre
100 pounds per acre
5,000 pounds per acre
1,500 to 2,000 pounds per acre (Correct answer)

Correct answer: 1,500 to 2,000 pounds per acre

A straw mulch application rate of approximately 1,500 to 2,000 pounds per acre typically achieves about 75% soil coverage, which is considered the minimum effective rate for erosion control.

Question 33: What should a CEPSCI inspector do when they observe a discharge of sediment-laden water leaving the site?

Wait until the next scheduled inspection
Contact the project owner only if the discharge is large
Document the discharge with photos, time, and location, and initiate immediate corrective action (Correct answer)
Ignore it if it appears minor

Correct answer: Document the discharge with photos, time, and location, and initiate immediate corrective action

Any discharge of sediment-laden water must be documented immediately with photographs, location, time, and estimated volume, and corrective actions must be initiated promptly to stop and prevent recurrence.

Question 34: What is the purpose of a corrective action log in SWPPP documentation?

To record worker disciplinary actions
To record daily weather observations
To log equipment maintenance
To track deficiencies found during inspections and document when and how they were corrected (Correct answer)

Correct answer: To track deficiencies found during inspections and document when and how they were corrected

A corrective action log creates a verifiable record showing that inspection deficiencies were identified, addressed, and resolved within required timeframes, demonstrating ongoing compliance.

Question 35: What is 'rill erosion' and how does it differ from sheet erosion?

Rill erosion only occurs near streams; sheet erosion occurs everywhere
Rill erosion is wind erosion; sheet erosion is water erosion
They are the same process described by different terms
Sheet erosion removes a uniform thin layer of soil; rill erosion involves concentrated flow that carves small channels into the soil surface (Correct answer)

Correct answer: Sheet erosion removes a uniform thin layer of soil; rill erosion involves concentrated flow that carves small channels into the soil surface

Sheet erosion is the relatively uniform removal of thin soil layers, while rill erosion begins when runoff concentrates into small channels, greatly increasing erosive power and sediment delivery.

Question 36: Which of the following is a sign that a post-construction bioretention cell is failing or clogged?

Native plants are flourishing in the cell
Bird and insect activity is observed in the cell
Water ponds in the cell for more than 72–96 hours after a storm event, indicating clogged media or an outlet problem (Correct answer)
The cell drains rapidly within a few minutes of a storm

Correct answer: Water ponds in the cell for more than 72–96 hours after a storm event, indicating clogged media or an outlet problem

Extended ponding in a bioretention cell indicates that the engineered soil media or underdrain has clogged, requiring sediment removal or media replacement to restore treatment function.

Question 37: Hydroseeding is most effectively used as:

A technique for compacting disturbed soils
A sediment trapping device at storm drain inlets
A substitute for silt fences on steep slopes
A temporary or permanent vegetative stabilization method applied as a slurry to exposed slopes (Correct answer)

Correct answer: A temporary or permanent vegetative stabilization method applied as a slurry to exposed slopes

Hydroseeding delivers a mixture of seed, mulch, fertilizer, and water in a slurry that adheres to slopes, providing rapid vegetative cover for erosion control.

Question 38: What is 'topsoil salvage and replacement' and why is it important in site restoration?

Stripping and stockpiling native topsoil before grading and replacing it after final grade is achieved to support vegetation establishment (Correct answer)
Removing contaminated soil from the site and replacing it with clean fill
Mixing topsoil with concrete to create a stabilized base
Importing topsoil from another site to replace subsoil

Correct answer: Stripping and stockpiling native topsoil before grading and replacing it after final grade is achieved to support vegetation establishment

Preserving native topsoil's biological and physical properties and returning it after grading greatly accelerates revegetation success compared to seeding on exposed subsoil alone.

Question 39: Soil compaction on a construction site affects revegetation success primarily by:

Improving drainage for plant roots
Increasing soil nutrient availability
Reducing pore space and limiting root penetration, water infiltration, and air exchange needed for plant establishment (Correct answer)
Accelerating seed germination rates

Correct answer: Reducing pore space and limiting root penetration, water infiltration, and air exchange needed for plant establishment

Compacted soils have reduced pore space, which limits root penetration, restricts water infiltration, and reduces oxygen availability, all of which severely impair plant establishment and growth.

Question 40: When is it appropriate to use polyacrylamide (PAM) as an erosion control amendment?

As a replacement for all physical BMPs on the site
As a soil amendment applied to disturbed soils to reduce erosion, typically in conjunction with seeding and mulching (Correct answer)
When no other BMPs are available and slope gradients exceed 80%
Only in wetland areas to stabilize aquatic sediments

Correct answer: As a soil amendment applied to disturbed soils to reduce erosion, typically in conjunction with seeding and mulching

PAM is an anionic polymer that binds soil particles together, reducing erosion and improving water quality when applied to disturbed soils along with other BMPs.

Question 41: Which device is most commonly used in the field to measure turbidity during stormwater monitoring?

Turbidimeter or nephelometer (Correct answer)
Spectrophotometer
Conductivity meter
Dissolved oxygen probe

Correct answer: Turbidimeter or nephelometer

A turbidimeter or nephelometer measures light scattered by particles in water and is the standard field instrument for turbidity monitoring.

Question 42: After construction is complete, what triggers the requirement to remove temporary BMPs such as silt fences?

Achievement of final stabilization of all disturbed areas and formal permit termination (Correct answer)
When the regulatory agency issues a removal order
The issuance of a certificate of occupancy for the buildings on site
The end of the rainy season following project completion

Correct answer: Achievement of final stabilization of all disturbed areas and formal permit termination

Temporary BMPs should remain until the site achieves final stabilization to ensure continuous protection; their removal before that point creates compliance liability.

Question 43: What is the purpose of a 'slope drain' or 'temporary slope drain pipe'?

To convey concentrated runoff down a slope without causing erosion by protecting the slope surface from flow (Correct answer)
To supply water to construction workers on steep slopes
To pump sediment-laden water to a treatment area
To drain groundwater from the slope face

Correct answer: To convey concentrated runoff down a slope without causing erosion by protecting the slope surface from flow

Slope drains are pipes anchored to the slope surface that convey concentrated runoff from the top to the bottom of a slope without allowing the flow to contact and erode the slope face.

Question 44: Which factor is NOT typically evaluated during a site's pre-construction erosion control assessment?

Adjacent property owner's personal finances (Correct answer)
Slope gradient and length
Rainfall intensity and frequency
Soil type and erodibility

Correct answer: Adjacent property owner's personal finances

Pre-construction assessments focus on physical site characteristics such as soil, slope, rainfall, and hydrology, not the financial status of adjacent property owners.

Question 45: A skimmer outlet on a sediment basin is designed to:

Draw water from the surface of the pool to minimize turbulence and discharge the clearest water (Correct answer)
Filter sediment using a screen
Prevent fish from entering the basin
Measure water depth

Correct answer: Draw water from the surface of the pool to minimize turbulence and discharge the clearest water

A floating skimmer draws water from just below the surface, discharging the clearest, least turbid water while keeping the turbid bottom water retained for further settling.

Question 46: The main benefit of using mulches and ECBs is that they:

Provide instant cover (Correct answer)
Last 4-6 years which is longer than the life of most construction projects
Are not living like vegetation
Do not have to be anchored

Correct answer: Provide instant cover

Explanation: Mulches (such as wood chips or straw) and ECBs (Erosion Control Blankets) provide instant cover to bare soil upon installation. This immediate coverage helps to protect the soil from rain impact, reduce surface runoff, and prevent erosion before vegetation can become established. It is a critical initial step in erosion and sediment control on construction sites and other disturbed areas. Unlike vegetation, which takes time to grow and provide cover, mulches, and ECBs offer an immediate solution to stabilize soil and prevent erosion during the early stages of project development. This early protection is essential for maintaining soil integrity and preventing sediment runoff into nearby water bodies or storm drains.

Question 47: If a state regulatory inspector visits a construction site and the SWPPP is not available, the likely consequence is:

Automatic suspension of all work
A notice of violation that may result in fines for failure to maintain required records (Correct answer)
Criminal charges against the project manager
A verbal warning with no further action

Correct answer: A notice of violation that may result in fines for failure to maintain required records

Failure to have the SWPPP available on-site constitutes a permit violation that can result in a notice of violation and potential financial penalties.

Question 48: What is the difference between 'erosion' and 'sedimentation' in the context of ESC?

Sedimentation occurs on slopes; erosion occurs in water bodies
They are the same process described differently by engineers vs. regulators
Erosion is a beneficial process; sedimentation is always harmful
Erosion is the detachment and transport of soil particles; sedimentation is the deposition of those transported particles in a new location (Correct answer)

Correct answer: Erosion is the detachment and transport of soil particles; sedimentation is the deposition of those transported particles in a new location

Erosion occurs at the source where soil is detached and moved; sedimentation is what happens downstream when transported particles lose momentum and settle, often clogging channels or water bodies.

Question 49: What is the purpose of a diversion dike on a construction site?

To redirect clean runoff away from disturbed areas or to route runoff to a BMP (Correct answer)
To separate different construction crews
To mark equipment exclusion zones
To stockpile excavated material

Correct answer: To redirect clean runoff away from disturbed areas or to route runoff to a BMP

Diversion dikes are earthen berms that redirect surface runoff away from disturbed areas or channel it toward a sediment control BMP to prevent uncontrolled runoff.

Question 50: Which soil characteristic most directly influences erodibility on a construction site?

Soil temperature
Soil pH
Soil texture and structure (Correct answer)
Soil color

Correct answer: Soil texture and structure

Soil texture and structure determine how easily particles are detached and transported by water or wind, making them the primary factors in erodibility.

Question 51: When sizing a sediment trap, the primary design parameter is:

Distance from the site entrance
Trap length only
Surface area based on the settling velocity of target sediment particles (Correct answer)
Trap depth only

Correct answer: Surface area based on the settling velocity of target sediment particles

Sediment trap surface area is designed based on the settling velocity of target sediment particles and the design flow rate, ensuring particles have sufficient residence time to settle out.

Question 52: Why is it important to minimize runoff velocity on a construction site?

Higher velocity improves sediment settling in basins
Lower velocity reduces the erosive energy that detaches and transports soil particles (Correct answer)
Higher velocity improves BMP performance
Velocity has no effect on erosion

Correct answer: Lower velocity reduces the erosive energy that detaches and transports soil particles

Runoff velocity directly determines erosive energy; slower flows have less capacity to detach and transport soil particles, reducing overall sediment production and transport.

Question 53: A construction site is located adjacent to a cold-water fishery. Which additional water quality parameter may be especially important to monitor beyond standard turbidity?

Color units
Electrical conductivity
Total dissolved solids
Dissolved oxygen (Correct answer)

Correct answer: Dissolved oxygen

Cold-water fisheries are highly sensitive to dissolved oxygen depletion, which can be exacerbated by elevated sediment loads and organic matter in runoff.

Question 54: A culvert on a construction site requires an outlet protection apron primarily to:

Redirect flow to a sediment basin
Mark the pipe location
Filter sediment from the flow
Dissipate energy and prevent scour at the pipe outlet (Correct answer)

Correct answer: Dissipate energy and prevent scour at the pipe outlet

Outlet protection aprons made of riprap dissipate the high-velocity flow exiting a culvert to prevent scour erosion at the outlet and downstream channel.

Question 55: Why should the embankment of a temporary sediment basin be inspected after every significant storm?

To verify the outlet pipe is clean
To measure sediment accumulation only
To check for vandalism
To identify signs of seepage, settlement, or erosion that could lead to embankment failure (Correct answer)

Correct answer: To identify signs of seepage, settlement, or erosion that could lead to embankment failure

Post-storm inspections identify early signs of embankment distress including piping seepage, settlement, cracking, or erosion that must be corrected before they progress to catastrophic failure.

Question 56: A tackifier is added to hydroseeding mixtures to:

Bond the mulch and seed to the soil surface and prevent displacement by rain and wind (Correct answer)
Kill weeds in the seed mix
Speed up seed germination time
Increase fertilizer availability

Correct answer: Bond the mulch and seed to the soil surface and prevent displacement by rain and wind

Tackifiers are binding agents that adhere the hydroseeding slurry to the soil surface, preventing seeds and mulch from being washed or blown away before vegetation can establish.

Question 57: Time of concentration in hydrology refers to:

The time needed for sediment to settle in a basin
The duration of a rainfall event
The time for runoff to travel from the most remote point in a watershed to the outlet (Correct answer)
The time required to install a BMP

Correct answer: The time for runoff to travel from the most remote point in a watershed to the outlet

Time of concentration is the time it takes for runoff from the hydraulically most distant point in a drainage area to reach the outlet, which affects peak discharge calculations.

Question 58: Which post-construction BMP is specifically designed to remove pollutants from stormwater before it discharges from a developed site?

A silt fence
A stabilized construction entrance
A diversion dike
A post-construction stormwater management facility such as a bioretention cell or wet pond (Correct answer)

Correct answer: A post-construction stormwater management facility such as a bioretention cell or wet pond

Post-construction stormwater management facilities (bioretention, extended detention basins, wet ponds) are designed to treat runoff from the completed development for the long term.

Question 59: Which grass species is commonly used for temporary seeding in the eastern US because of its rapid germination and growth?

Annual ryegrass or cereal rye (Correct answer)
St. Augustine grass
Kentucky bluegrass
Bermudagrass

Correct answer: Annual ryegrass or cereal rye

Annual ryegrass and cereal rye germinate and establish quickly, making them ideal for temporary erosion control seeding in the eastern United States during cool and transitional seasons.

Question 60: What is the purpose of applying mulch over seeded areas on a construction site?

To add nutrients to the soil
To make the site look more attractive
To retain soil moisture, regulate temperature, protect seeds from displacement, and reduce erosion until vegetation establishes (Correct answer)
To prevent weeds from growing

Correct answer: To retain soil moisture, regulate temperature, protect seeds from displacement, and reduce erosion until vegetation establishes

Mulch creates a protective layer over seeded soil that retains moisture for germination, moderates soil temperature extremes, prevents seed displacement by rain and wind, and reduces surface erosion.

Question 61: What is a 'vegetated filter strip' used for in post-construction stormwater management?

A strip of pavement adjacent to a parking lot
A buffer of trees planted around a building for aesthetic purposes
An ornamental landscape feature along property boundaries
A uniformly graded, densely vegetated area that treats sheet flow runoff by filtering sediment and infiltrating water before it enters a stream or water body (Correct answer)

Correct answer: A uniformly graded, densely vegetated area that treats sheet flow runoff by filtering sediment and infiltrating water before it enters a stream or water body

Vegetated filter strips treat sheet flow from adjacent impervious areas, reducing sediment, nutrients, and other pollutants before runoff reaches receiving waters.

Question 62: When a CEPSCI inspector finds a failed silt fence during an inspection, the first required action is to:

Remove the failed BMP permanently
Notify the project architect
Document the deficiency and ensure immediate repair within a specified timeframe (Correct answer)
Wait until the next scheduled maintenance

Correct answer: Document the deficiency and ensure immediate repair within a specified timeframe

Inspectors must document the deficiency and ensure corrective action is completed within the timeframe required by the permit, often 7 days or within 24 hours for active discharges.

Question 63: The SWPPP must be amended when:

Only after a regulatory inspection
Only at the end of the project
Site conditions change, new BMPs are added, or inspections reveal existing controls are inadequate (Correct answer)
The project manager requests it

Correct answer: Site conditions change, new BMPs are added, or inspections reveal existing controls are inadequate

The SWPPP is a living document that must be updated whenever site conditions change, BMPs are modified, or inspections indicate that current controls are not functioning adequately.

Question 64: Which of the following is a source control BMP rather than a treatment BMP?

Sediment basin
Phased construction limiting the area of disturbance (Correct answer)
Silt fence
Sediment trap

Correct answer: Phased construction limiting the area of disturbance

Source controls prevent sediment from being generated in the first place by limiting disturbed area, while treatment BMPs capture sediment after it has been mobilized; source controls are always preferable.

Question 65: What information must be documented in a BMP inspection report?

Only photographs of the site
Worker names and salaries
Only instances of permit violations
Date, inspector name, weather conditions, BMP status, any discharges, and corrective actions taken (Correct answer)

Correct answer: Date, inspector name, weather conditions, BMP status, any discharges, and corrective actions taken

Inspection reports must document the date and time, inspector's name, weather conditions, condition and effectiveness of each BMP, any discharges observed, and corrective actions needed or taken.

Question 66: Why is it important to preserve and reuse topsoil stockpiled during construction?

Topsoil must be discarded to prevent weed seed spread
Topsoil has no value once it is removed from its original location
Topsoil contains the organic matter, nutrients, and soil structure necessary for vegetation establishment, making revegetation faster and more successful (Correct answer)
Topsoil can be used as fill material in embankments

Correct answer: Topsoil contains the organic matter, nutrients, and soil structure necessary for vegetation establishment, making revegetation faster and more successful

Topsoil's biological and physical properties support plant establishment far better than subsoil; spreading it back over disturbed areas after grading accelerates permanent stabilization.

Question 67: The term 'disturbed area' on a construction site refers to:

Sections of the site with poor drainage
Areas where workers have disagreements
Any land area where vegetation, topsoil, or surface has been removed or altered (Correct answer)
Areas where equipment is stored overnight

Correct answer: Any land area where vegetation, topsoil, or surface has been removed or altered

Disturbed area refers to any land where the vegetative cover, topsoil, or ground surface has been removed or altered, exposing soil to erosion.

Question 68: After final grading, what is the recommended maximum time before temporary or permanent stabilization should be initiated on disturbed areas under the NPDES CGP?

90 days after the entire project is complete
14 days after grading activity has ceased in that portion of the site (Correct answer)
30 days after grading ceases
No time limit is specified in the federal CGP

Correct answer: 14 days after grading activity has ceased in that portion of the site

The NPDES CGP requires initiation of stabilization within 14 days after the last land-disturbing activity in any area, minimizing the window of erosion vulnerability.

Question 69: The best time to seed a disturbed site in temperate climates is typically:

Midsummer during the hottest temperatures
Immediately before a forecasted hard freeze
Late summer to early fall or early spring when temperatures favor germination and soil moisture is adequate (Correct answer)
During the driest month of the year

Correct answer: Late summer to early fall or early spring when temperatures favor germination and soil moisture is adequate

Late summer to early fall and early spring provide ideal soil temperatures and moisture conditions for seed germination in temperate climates, maximizing establishment success.

Question 70: How often must construction site BMP inspections be conducted under most state NPDES Construction General Permits?

Only before significant storms
Once per month
At least every 7 days and within 24 hours after a 0.5-inch or greater rainfall event (Correct answer)
Annually

Correct answer: At least every 7 days and within 24 hours after a 0.5-inch or greater rainfall event

Most NPDES Construction General Permits require inspections at least every 7 calendar days and within 24 hours of a qualifying rainfall event to ensure BMPs are functioning properly.

Question 71: A discharge point on a construction site SWPPP map is defined as:

The main contractor's parking area
The location of portable restrooms
The location of the site entrance gate
Any location where stormwater leaves the construction site boundary (Correct answer)

Correct answer: Any location where stormwater leaves the construction site boundary

Discharge points are all locations where stormwater runoff exits the construction site boundary, and each must be identified on the SWPPP site map and monitored during inspections.

Question 72: What is 'gully erosion' and why is it significant on construction sites?

Advanced-stage erosion where rills merge into large, deep channels that cannot be crossed by equipment, indicating severe loss of soil (Correct answer)
Minor surface staining that does not involve soil loss
Erosion that occurs only below the water table
Erosion that occurs only in sandy coastal areas

Correct answer: Advanced-stage erosion where rills merge into large, deep channels that cannot be crossed by equipment, indicating severe loss of soil

Gully erosion represents extreme concentration of runoff that has cut deeply into the soil, removing large volumes of material and potentially destabilizing adjacent areas.

Question 73: What are the three types of soil particles, listed from largest to smallest?

Loam, sand, gravel
Clay, silt, sand
Sand, silt, clay (Correct answer)
Gravel, sand, silt

Correct answer: Sand, silt, clay

Soil texture is determined by the relative proportions of sand (0.05–2 mm), silt (0.002–0.05 mm), and clay (<0.002 mm) particles.

Question 74: A peak discharge from a construction site is most critical because:

It represents the highest flow rate BMPs must handle without failure (Correct answer)
It sets the final cost of the project
It determines the daily work schedule
It determines the number of workers needed

Correct answer: It represents the highest flow rate BMPs must handle without failure

Peak discharge is the maximum flow rate during a storm event, and BMPs must be designed to handle this flow without being overwhelmed or failing.

Question 75: A Stormwater Pollution Prevention Plan (SWPPP) must be developed for sites disturbing:

Five acres or more of land
One acre or more of land (Correct answer)
Any amount of soil
Ten acres or more of land

Correct answer: One acre or more of land

Under the EPA Construction General Permit, a SWPPP is required for construction sites disturbing one acre or more, or less than one acre if part of a larger common plan of development.

Question 76: The rational method formula Q = CiA is used to calculate:

Peak stormwater runoff rate (Correct answer)
BMP maintenance frequency
Sediment pond volume
Soil erodibility

Correct answer: Peak stormwater runoff rate

The rational method calculates peak runoff rate (Q) using the runoff coefficient (C), rainfall intensity (i), and drainage area (A).

Question 77: When should a temporary sediment basin be cleaned out?

When sediment accumulation reaches 50% of the designed wet storage volume (Correct answer)
Never; basins are designed to fill completely
Only when it is completely full
After every rainfall event

Correct answer: When sediment accumulation reaches 50% of the designed wet storage volume

Sediment basins should be cleaned out when accumulated sediment reaches approximately 50% of the wet storage volume to maintain hydraulic capacity and sediment removal efficiency.

Question 78: What is the primary purpose of inlet protection (e.g., a filter sock or gravel bag around a storm drain inlet)?

To prevent sediment-laden runoff from entering the storm drain system (Correct answer)
To increase the capacity of the storm drain
To mark the inlet location for the contractor
To aerate the water before it enters the drain

Correct answer: To prevent sediment-laden runoff from entering the storm drain system

Inlet protection devices filter sediment out of runoff before it enters the storm drain, preventing sediment from being conveyed off-site through the stormwater system.

Question 79: A buffer zone around a stream on a construction site primarily serves to:

Designate areas for topsoil stockpiles
Mark property boundaries
Protect the stream bank from disturbance and filter runoff before it reaches the water (Correct answer)
Provide equipment staging area

Correct answer: Protect the stream bank from disturbance and filter runoff before it reaches the water

Buffer zones protect stream banks from direct disturbance and allow vegetation and soil to filter sediment and pollutants from runoff before it enters the waterway.

Question 80: Which factor in the rational method accounts for the type of ground surface?

Q (peak runoff rate)
i (rainfall intensity)
A (drainage area)
C (runoff coefficient) (Correct answer)

Correct answer: C (runoff coefficient)

The runoff coefficient (C) represents the fraction of rainfall that becomes runoff, which varies based on ground cover type, soil type, and slope.

Question 81: When planning construction phasing to minimize erosion, the best approach is to:

Focus disturbance near the site entrance first
Limit the area of disturbance at any one time and stabilize completed areas before moving on (Correct answer)
Disturb the entire site at once to complete faster
Disturb all slopes simultaneously

Correct answer: Limit the area of disturbance at any one time and stabilize completed areas before moving on

Phased disturbance limits the area of exposed soil at any given time, reducing the volume of potential sediment generation and making BMPs more manageable.

CEPSCI Certification Exam

The CEPSCI exam certifies erosion prevention and sediment control inspectors, testing knowledge of BMPs, stormwater management, inspection procedures, regulatory compliance, and site restoration under the Clemson University/EnviroCert program.

Questions

180 min

Time Limit

75%

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