Environmental Engineering and Stormwater Management Flashcards
6 cards from real Civil Engineering PE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Environmental Engineering and Stormwater Management flashcards as text
Biochemical oxygen demand (BOD) measures:
Answer: Oxygen consumed by microorganisms decomposing organic matter
BOD quantifies dissolved oxygen consumed by biological processes decomposing organic matter, typically measured over 5 days at 20°C (BOD₅).
The Streeter-Phelps DO sag curve downstream of a wastewater outfall shows:
Answer: A dissolved oxygen deficit that deepens then recovers downstream
The DO sag model predicts a critical minimum at the point where deoxygenation rate equals reaeration rate, after which DO recovers as organic demand decreases.
An NPDES permit under the Clean Water Act regulates:
Answer: Point source discharges of pollutants to navigable waters of the US
NPDES requires permits for any discrete point source discharging pollutants into waters of the United States, setting effluent limits and monitoring requirements.
A bioretention cell (rain garden) removes stormwater pollutants primarily through:
Answer: Filtration through engineered soil media combined with plant uptake
Bioretention systems filter runoff through an engineered soil mix, removing TSS, metals, and nutrients via physical filtration, adsorption, and plant/microbial uptake.
A Total Maximum Daily Load (TMDL) establishes:
Answer: The maximum pollutant load a water body can receive and still meet water quality standards
A TMDL is the total pollutant loading capacity of a water body, allocated among point sources (WLA), nonpoint sources (LA), and a margin of safety (MOS).
NPDES Construction General Permits require a Stormwater Pollution Prevention Plan (SWPPP) for land disturbance areas of:
Answer: 1 acre or more
Federal NPDES CGP requirements apply to construction sites disturbing 1 acre or more, requiring a SWPPP with erosion and sediment controls.