Mixed Deck — All CEPSCI Topics Flashcards

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

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.

What soil amendment is most commonly applied before seeding to improve germination on disturbed sites?

Answer: Lime and fertilizer based on soil test results

Soil testing guides the application of lime to adjust pH and fertilizer to provide nutrients, both of which are critical for successful seed germination and establishment on disturbed soils.

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

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.

What is 'bioretention' (rain garden) as a post-construction BMP?

Answer: A shallow, vegetated depression that captures and treats stormwater through filtration, infiltration, and plant uptake

Bioretention cells use engineered soil media and native plants to filter stormwater pollutants, reduce runoff volume through infiltration, and attenuate peak flows.

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

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.

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

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.

Under the EPA's Construction General Permit (CGP), operators must conduct water quality monitoring when a project discharges to a water body that is impaired for which of the following?

Answer: Sediment or turbidity

The CGP requires enhanced monitoring when construction sites discharge to 303(d)-listed impaired water bodies for sediment or turbidity.

Which BMP is most appropriate for protecting a storm drain inlet in a parking lot?

Answer: A curb inlet protection device or filter bag designed to fit the specific inlet type

Curb inlet protection devices and sediment filter bags are engineered to fit standard curb inlet dimensions, effectively trapping sediment while allowing flow to continue into the drainage system.

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

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.

Where are sediment tubes typically installed to reduce soil erosion and retain sediment?

Answer: In drainage conveyance swales as ditch checks.

Explanation: Sediment tubes are commonly used as erosion control measures in drainage conveyance swales. They serve as ditch checks to slow down the flow of water, allowing sediment to settle out before it leaves the site. By retaining sediment within the swales, sediment tubes help to prevent erosion and reduce the amount of sediment entering stormwater systems or water bodies downstream.

What is the hydraulic residence time of a sediment basin?

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.

Why is it important to include the weather conditions at the time of inspection in inspection reports?

Answer: To establish context for BMP performance observations and demonstrate the inspection met permit requirements

Documenting weather conditions contextualizes BMP performance and demonstrates that inspections were actually conducted as required, since a functioning BMP observed during dry weather versus after rainfall tells a different compliance story.

Which statement best describes turf reinforcement mats (TRMs)?

Answer: Permanent erosion BMPs often used in areas of concentrated flows.

Explanation: Turf reinforcement mats (TRMs) are permanent Best Management Practices (BMPs) used primarily in areas with concentrated flows or where erosion control needs to be long-lasting and durable. TRMs are designed to stabilize soil and reinforce vegetation by providing protection against erosive forces such as rainfall and water flow. They are typically made of synthetic materials that are resistant to degradation and help to promote the establishment and growth of vegetation over time.

A turbidity curtain (silt curtain) is used to:

Answer: Contain sediment in open water bodies such as rivers, lakes, or bays during in-water work

Turbidity curtains are floating barriers deployed in water bodies to contain sediment plumes generated during in-water construction activities such as dredging or pile driving.

A skimmer outlet on a sediment basin is designed to:

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.

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

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.

What is the recommended aggregate size for a stabilized construction entrance?

Answer: Coarse aggregate 1.5 to 3 inches in diameter

Coarse aggregate in the 1.5 to 3 inch range is large enough to knock mud off tires through mechanical agitation as vehicles drive over it, while remaining stable under heavy equipment loads.

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

Answer: Turbidimeter or nephelometer

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

What is the purpose of a rock check dam in a drainage channel?

Answer: To slow flow velocity, reduce channel erosion, and trap sediment in the channel between storm events

Rock check dams reduce flow velocity in channels, decreasing erosive shear stress and trapping sediment between the dam and the next upstream dam during and after storm events.

What is the primary purpose of a temporary sediment basin on a construction site?

Answer: To capture and retain sediment-laden runoff, allowing sediment to settle out before water is discharged

Temporary sediment basins trap stormwater runoff and hold it long enough for suspended sediment to settle to the bottom before the clarified water is released through a controlled outlet.