CESSWI CESSWI Post-Construction BMP Maintenance and Long-Term Controls

Question 1

Under the EPA's Construction General Permit (CGP), when is a permittee typically required to transition from construction-phase BMPs to post-construction stormwater controls?

Accepted Answer

When the site reaches final stabilization and permit coverage is terminated

Answer

Immediately after final grading is complete

Answer

After the first post-construction inspection

Answer

30 days after the last rainfall event exceeding 0.5 inches

Question 2

A dry extended-detention basin is a post-construction BMP designed primarily to:

Accepted Answer

Detain stormwater temporarily to reduce peak discharge rates and allow sediment settling

Answer

Permanently pool water to provide wetland habitat

Answer

Infiltrate 100% of design storm runoff into groundwater

Answer

Filter runoff through a sand/gravel media

Question 3

Which post-construction BMP is specifically designed to reduce both runoff volume and pollutant loading through infiltration and evapotranspiration?

Accepted Answer

Bioretention cell (rain garden)

Answer

Riprap channel lining

Answer

Concrete flume

Answer

Rip-rap energy dissipater

Question 4

During a post-construction inspection of a wet retention pond, an inspector observes the permanent pool is 50% smaller than the design volume due to sediment accumulation. The required action is to:

Accepted Answer

Notify the owner that sediment must be removed to restore design storage capacity

Answer

Document the condition and re-inspect in 12 months

Answer

Add more water to compensate for lost volume

Answer

Plant additional vegetation around the pond perimeter

Question 5

Permeable pavement is classified as which type of Low Impact Development (LID) stormwater practice?

Accepted Answer

Volume reduction / green infrastructure BMP

Answer

Conveyance BMP

Answer

Sediment trapping BMP

Answer

Slope stabilization BMP

Question 6

Which inspection finding would trigger an immediate corrective action for a post-construction outlet structure?

Accepted Answer

Outlet pipe fully blocked with debris, causing the basin to overflow its embankment

Answer

Minor algae growth on the barrel walls

Answer

Water surface 1 foot below the design permanent pool elevation

Answer

Grass growing on the side slopes of the embankment