AQS Air Dispersion Modeling

Question 1

Which EPA-approved air dispersion model is the preferred regulatory model for most near-field (within ~50 km) stationary source applications?

Accepted Answer

AERMOD

Answer

AERMOD (American Meteorological Society/EPA Regulatory Model) is the EPA's preferred regulatory model for near-field dispersion from stationary sources.

Question 2

In the Pasquill-Gifford atmospheric stability classification system, which stability class represents the most unstable atmospheric conditions?

Accepted Answer

Class A

Answer

Class A is the most unstable Pasquill-Gifford stability class, occurring under strong solar radiation and light surface winds.

Question 3

The Gaussian plume model assumes that pollutant concentrations follow what type of statistical distribution in both the horizontal and vertical directions from the plume centerline?

Accepted Answer

Normal (Gaussian) distribution

Answer

The Gaussian plume model assumes a normal (bell-curve) distribution of pollutant concentrations both crosswind and vertically from the plume centerline.

Question 4

The AERMET meteorological preprocessor is used to prepare which type of data for input into AERMOD?

Accepted Answer

Surface meteorological and upper-air sounding data

Answer

AERMET processes surface meteorological observations and upper-air soundings to derive planetary boundary layer parameters required by AERMOD.

Question 5

In air dispersion modeling, 'effective stack height' is defined as the sum of the physical stack height plus:

Accepted Answer

Plume rise due to momentum and buoyancy of exhaust gases

Answer

Effective stack height equals physical stack height plus plume rise, which results from the upward momentum and buoyancy of hot exhaust gases.

(AQS) Air Quality Specialist Certification Practice Test

(AQS) Air Quality Specialist Certification Practice Test

AQS Air Dispersion Modeling