ETC Air Quality & Emissions Monitoring 2

Question 1

Under the Clean Air Act, what is a 'criteria pollutant'?

Accepted Answer

One of six common air pollutants for which EPA has set NAAQS to protect public health and welfare

Answer

The six criteria pollutants are CO, NO2, SO2, O3, PM2.5/PM10, and lead — pollutants widespread enough for EPA to set health-based ambient standards (NAAQS).

Question 2

What does PM10 refer to in air quality monitoring?

Accepted Answer

Particulate matter with an aerodynamic diameter of 10 micrometers or less

Answer

PM10 refers to inhalable particles with aerodynamic diameters of 10 micrometers (µm) or less, which can penetrate into the upper respiratory tract.

Question 3

What is 'opacity' as used in air emissions monitoring?

Accepted Answer

The percentage of light obscured by emissions leaving a stack or fugitive source

Answer

Opacity is the degree to which emissions block or reduce the transmission of light, expressed as a percentage; it is visually assessed using EPA Method 9.

Question 4

What is a fugitive emission?

Accepted Answer

An emission released from a source that is not captured by an exhaust hood or stack and vented to the atmosphere directly

Answer

Fugitive emissions escape from equipment, seals, or open areas without passing through a control device or stack, such as dust from unpaved roads or leaks from valves.

Question 5

What is the role of a 'zero gas' when calibrating a continuous air quality analyzer?

Accepted Answer

A gas with no detectable concentration of the target pollutant used to set the instrument's zero response

Answer

Zero gas (scrubbed air free of the target pollutant) is introduced to verify and adjust the instrument's zero point so it reads 0 when no pollutant is present.

ETC - Environmental Technician Certification Practice Test

ETC - Environmental Technician Certification Practice Test

ETC Air Quality & Emissions Monitoring 2