CPESC Stormwater Management 5

Question 1

Which federal regulation requires municipalities in urbanized areas to obtain NPDES permits for their stormwater discharges?

Accepted Answer

MS4 Phase I and Phase II rules under 40 CFR Part 122

Answer

The MS4 (Municipal Separate Storm Sewer System) Phase I and II rules require NPDES permits for stormwater discharges from urbanized area storm sewer systems.

Question 2

What is the purpose of a vegetated filter strip in stormwater management?

Accepted Answer

Remove pollutants and slow runoff velocity through sheet flow over dense vegetation

Answer

Vegetated filter strips treat sheet flow runoff by slowing velocity and allowing infiltration and filtering of sediment and associated pollutants through dense grass.

Question 3

In the context of watershed hydrology, what does 'time of concentration' (Tc) represent?

Accepted Answer

Time required for runoff to travel from the hydraulically most remote point to the watershed outlet

Answer

Time of concentration is the travel time of runoff from the most remote point in the watershed to the outlet, used to determine the critical duration storm for peak flow design.

Question 4

Which condition would INCREASE the runoff curve number (CN) for a site?

Accepted Answer

Paving a gravel parking lot with asphalt

Answer

Paving a gravel lot with asphalt increases imperviousness significantly, raising the CN value and increasing runoff volume and peak rates.

Question 5

A constructed wetland used for stormwater treatment primarily removes pollutants through which mechanisms?

Accepted Answer

Settling, biological uptake, microbial decomposition, and filtration through vegetation

Answer

Constructed stormwater wetlands remove pollutants through a combination of settling, plant uptake, microbial activity, and physical filtration through emergent vegetation.

(CPESC) Certified Professional in Erosion and Sediment Control Practice Test

(CPESC) Certified Professional in Erosion and Sediment Control Practice Test

CPESC Stormwater Management 5