Civil Engineering PE Environmental Engineering and Stormwater Management 2

Question 1

Biochemical oxygen demand (BOD) measures:

Accepted Answer

Oxygen consumed by microorganisms decomposing organic matter

Answer

BOD quantifies dissolved oxygen consumed by biological processes decomposing organic matter, typically measured over 5 days at 20°C (BOD₅).

Question 2

The Streeter-Phelps DO sag curve downstream of a wastewater outfall shows:

Accepted Answer

A dissolved oxygen deficit that deepens then recovers downstream

Answer

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.

Question 3

An NPDES permit under the Clean Water Act regulates:

Accepted Answer

Point source discharges of pollutants to navigable waters of the US

Answer

NPDES requires permits for any discrete point source discharging pollutants into waters of the United States, setting effluent limits and monitoring requirements.

Question 4

A bioretention cell (rain garden) removes stormwater pollutants primarily through:

Accepted Answer

Filtration through engineered soil media combined with plant uptake

Answer

Bioretention systems filter runoff through an engineered soil mix, removing TSS, metals, and nutrients via physical filtration, adsorption, and plant/microbial uptake.

Question 5

A Total Maximum Daily Load (TMDL) establishes:

Accepted Answer

The maximum pollutant load a water body can receive and still meet water quality standards

Answer

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).

Civil Engineering PE Practice Test

Civil Engineering PE Practice Test

Civil Engineering PE Environmental Engineering and Stormwater Management 2