Air Quality & Emissions Monitoring Flashcards
7 cards from real ETC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Air Quality & Emissions Monitoring flashcards as text
Under the Clean Air Act, what is a 'criteria pollutant'?
Answer: One of six common air pollutants for which EPA has set NAAQS to protect public health and welfare
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).
What does PM10 refer to in air quality monitoring?
Answer: Particulate matter with an aerodynamic diameter of 10 micrometers or less
PM10 refers to inhalable particles with aerodynamic diameters of 10 micrometers (µm) or less, which can penetrate into the upper respiratory tract.
What is 'opacity' as used in air emissions monitoring?
Answer: The percentage of light obscured by emissions leaving a stack or fugitive source
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.
What is a fugitive emission?
Answer: An emission released from a source that is not captured by an exhaust hood or stack and vented to the atmosphere directly
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.
What is the role of a 'zero gas' when calibrating a continuous air quality analyzer?
Answer: A gas with no detectable concentration of the target pollutant used to set the instrument's zero response
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.
Which Clean Air Act permit program requires large sources emitting above major source thresholds to obtain an operating permit that consolidates all air quality requirements?
Answer: Title V operating permit
Title V of the Clean Air Act requires major stationary sources to obtain an operating permit that incorporates all applicable air quality requirements into a single enforceable document.
What does the Ringelmann scale measure?
Answer: The visible density or darkness of smoke emissions from a stack
The Ringelmann scale is a visual reference tool using shaded gray cards numbered 0–5 to estimate smoke density/opacity from combustion sources.