CESSWI Post-Construction BMP Maintenance and Long-Term Controls Flashcards
6 cards from real CESSWI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CESSWI Post-Construction BMP Maintenance and Long-Term Controls flashcards as text
In the context of post-construction stormwater management, what does 'hydromodification' refer to?
Answer: Changes in the natural hydrologic cycle (peak flows, runoff volume, duration) caused by land development
Hydromodification describes how impervious surfaces and altered drainage increase peak flows, total runoff volume, and flow duration compared to pre-development conditions, degrading stream channels.
A vegetated filter strip used as a post-construction BMP functions primarily by:
Answer: Slowing sheet flow and allowing settling and infiltration of runoff from adjacent impervious areas
Vegetated filter strips use dense grass or other vegetation to slow shallow sheet flow, promote infiltration, and physically filter out sediments and other pollutants before runoff enters a water body.
Which maintenance activity is most critical for ensuring continued function of an underground stormwater infiltration system?
Answer: Removing accumulated sediment from pretreatment devices to prevent clogging of the infiltration media
Sediment accumulation in upstream pretreatment structures (catch basins, forebays) is the primary cause of infiltration system failure; regular cleanout preserves the system's ability to percolate stormwater.
Under many MS4 (Municipal Separate Storm Sewer System) permits, what is the purpose of requiring a Stormwater Pollution Prevention Plan (SWPPP) for post-construction activities?
Answer: To document long-term maintenance responsibilities, inspection schedules, and ownership of post-construction BMPs
Post-construction SWPPPs or equivalent O&M agreements create a legally binding record of who is responsible for maintaining BMPs and how often inspections and maintenance must be performed.
Green roofs are considered a post-construction LID BMP because they primarily:
Answer: Retain rainwater in a growing media layer, reducing and delaying roof runoff to the storm sewer
The saturated growing medium on a green roof absorbs rainfall, which is then returned to the atmosphere through evapotranspiration, reducing the volume and peak rate of runoff from the roof.
An inspector discovers that a post-construction wet pond outlet's trash rack is missing. The most important reason to replace it immediately is to:
Answer: Prevent debris from blocking the outlet pipe, which could cause uncontrolled overflow and embankment failure
Trash racks keep large debris from entering and blocking the outlet barrel; without one, clogging can cause water levels to exceed the embankment and lead to erosive overtopping or structural failure.