CPESC Inspection Procedures 4 — Questions and Answers
Question 1: Which of the following is a key item to verify when inspecting a silt fence installation?
- The brand and manufacturer of the geotextile fabric
- That the fabric is trenched and backfilled at least 6 inches below grade (Correct answer)
- That the fence is painted high-visibility orange
- That the posts are spaced no more than 12 feet apart on flat terrain
Correct answer: That the fabric is trenched and backfilled at least 6 inches below grade
Proper toe-in burial (typically 6–8 inches) prevents stormwater from undermining the silt fence and bypassing the sediment barrier.
Question 2: What does a 'Notice of Termination' (NOT) signal in the context of a construction site NPDES permit?
- The contractor has left the site due to non-payment
- The permittee is notifying the agency that final stabilization has been achieved and permit coverage is no longer needed (Correct answer)
- The regulatory agency is revoking the site's permit
- The project owner is transferring permit responsibility to a new operator
Correct answer: The permittee is notifying the agency that final stabilization has been achieved and permit coverage is no longer needed
An NOT is filed when a site meets final stabilization criteria, officially ending permit coverage and inspection obligations.
Question 3: During a rainfall inspection, a CPESC professional observes that a bioretention cell is overflowing its emergency spillway. What does this most likely indicate?
- The cell is functioning as designed during a design storm event
- The underdrain system or infiltration capacity is impaired and needs maintenance (Correct answer)
- The inlet pipe is undersized for the drainage area
- The cell needs additional native plantings to improve function
Correct answer: The underdrain system or infiltration capacity is impaired and needs maintenance
Overflow from an emergency spillway during moderate storms typically signals that the underdrain or infiltration capacity is clogged or otherwise impaired.
Question 4: An inspector must evaluate whether a slope is 'steep' for BMP selection purposes. Which slope gradient is commonly used as the threshold between standard and steep slope conditions in erosion control?
- 3:1 (H:V)
- 2:1 (H:V) (Correct answer)
- 4:1 (H:V)
- 10:1 (H:V)
Correct answer: 2:1 (H:V)
A 2:1 (H:V) slope is commonly used as the threshold for steep slopes requiring more robust erosion control measures than standard slope BMPs.
Question 5: Which of the following records is required to be kept on-site or readily available during a regulatory inspection of a construction project?
- The contractor's business license and bonding documentation
- The current SWPPP, including all amendments and inspection reports (Correct answer)
- The project's building permit and architectural drawings
- The subcontractor list and their insurance certificates
Correct answer: The current SWPPP, including all amendments and inspection reports
Most NPDES CGPs require the SWPPP and all associated inspection logs and amendment records to be available on-site for regulatory review at any time.
Question 6: A newly seeded slope shows signs of rill erosion after a moderate rain event. Which inspection finding best explains this outcome?
- The seed mix was applied at too high a rate
- Germination has not yet established sufficient ground cover to protect the soil (Correct answer)
- The slope aspect is north-facing, reducing sunlight
- The seed mix included species not native to the region
Correct answer: Germination has not yet established sufficient ground cover to protect the soil
Temporary seeding provides no protection until germination establishes ground cover, making newly seeded slopes vulnerable to erosion in the interim period.
Question 7: Which action should an inspector take when a BMP deficiency is identified that poses an imminent threat to a waterway?
- Log the deficiency in the next scheduled inspection report
- Notify the operator immediately and require same-day corrective action (Correct answer)
- Issue a written notice with a 14-day correction window
- Wait until after the current storm event has passed before requiring repairs
Correct answer: Notify the operator immediately and require same-day corrective action
Imminent threats to waterways require immediate notification and same-day corrective action to prevent ongoing water quality violations.
CPESC Inspection Procedures 4
Which of the following is a key item to verify when inspecting a silt fence installation?