PIC EPA Stormwater & Erosion Control 2 — Questions and Answers
Question 1: Under the EPA Construction General Permit (CGP), a SWPPP must be developed and implemented before land disturbance begins on sites disturbing at least how many acres?
- 0.5 acres
- 1 acre (Correct answer)
- 2 acres
- 5 acres
Correct answer: 1 acre
The CGP requires a SWPPP for construction sites that disturb 1 or more acres, or that are part of a larger common plan of development.
Question 2: Which type of erosion control BMP is specifically designed to slow runoff velocity on steep slopes by creating a series of small check structures?
- Silt fence
- Sediment basin
- Rock check dams (Correct answer)
- Fiber rolls
Correct answer: Rock check dams
Rock check dams are placed in drainage channels or swales to reduce flow velocity and allow sediment to settle before water leaves the site.
Question 3: During a paving project, a contractor places a concrete washout pit 30 feet from a storm drain inlet. What is the primary concern with this placement?
- It violates minimum setback requirements from storm drains (Correct answer)
- The pit is too close to equipment traffic lanes
- Washout pits must be lined with impervious material only
- Concrete pH is not regulated under stormwater rules
Correct answer: It violates minimum setback requirements from storm drains
Concrete washout areas must be placed well away from storm drains and waterways to prevent high-pH washwater from entering the storm system.
Question 4: What is the purpose of a stabilized construction entrance (SCE) at a paving project site?
- To filter vehicle exhaust before it enters the atmosphere
- To reduce tracking of sediment onto public roads by construction vehicles (Correct answer)
- To provide a safe loading zone for heavy equipment
- To divert clean stormwater around the disturbed area
Correct answer: To reduce tracking of sediment onto public roads by construction vehicles
A stabilized construction entrance, typically made of coarse aggregate, removes mud and sediment from vehicle tires before they exit the site onto public roads.
Question 5: Which document under the NPDES stormwater program identifies site-specific BMPs and is required to be kept on-site during construction?
- Notice of Intent (NOI)
- Stormwater Pollution Prevention Plan (SWPPP) (Correct answer)
- Notice of Termination (NOT)
- Erosion Hazard Rating (EHR)
Correct answer: Stormwater Pollution Prevention Plan (SWPPP)
The SWPPP must be kept at the construction site and made available for inspection by the permitting authority at all times.
Question 6: An inspector observes a brown, turbid discharge leaving a paving site during a rain event. What is the most likely regulatory concern?
- Violation of air quality permits
- Potential exceedance of the permit's turbidity benchmark for sediment-laden discharge (Correct answer)
- Violation of solid waste disposal regulations
- Noncompliance with noise ordinance requirements
Correct answer: Potential exceedance of the permit's turbidity benchmark for sediment-laden discharge
Turbid (cloudy, sediment-laden) discharges from construction sites may exceed benchmark NTU values in the CGP, triggering corrective action requirements.
Question 7: Under the EPA CGP, how frequently must routine stormwater inspections be conducted at a construction site during active construction?
- Daily
- At least once every 7 calendar days
- At least once every 14 calendar days and within 24 hours after a 0.25-inch rain event (Correct answer)
- Monthly
Correct answer: At least once every 14 calendar days and within 24 hours after a 0.25-inch rain event
The CGP requires inspections at least every 14 days and within 24 hours of a qualifying storm event of 0.25 inches or more of rainfall.
PIC EPA Stormwater & Erosion Control 2
Under the EPA Construction General Permit (CGP), a SWPPP must be developed and implemented before land disturbance begins on sites disturbing at least how many acres?