CES Air Quality Monitoring & Standards 3

Question 1

The Air Quality Index (AQI) is calculated using which set of pollutants?

Accepted Answer

PM2.5, PM10, O3, CO, SO2, NO2

Answer

The AQI is computed for six pollutants: PM2.5, PM10, ground-level ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide, with the highest sub-index reported.

Question 2

In dispersion modeling, the Pasquill-Gifford stability classes range from A to F, where class A represents:

Accepted Answer

Extremely unstable daytime conditions

Answer

Pasquill-Gifford class A denotes extremely unstable atmospheric conditions (strong insolation, low wind speed), leading to rapid vertical mixing and dilution of pollutants.

Question 3

Which monitoring siting criterion in 40 CFR Part 58 Appendix E specifies the minimum distance a monitor must be from a roadway to measure neighborhood-scale PM2.5?

Accepted Answer

25 meters

Answer

For neighborhood-scale PM2.5 monitoring, 40 CFR Part 58 Appendix E requires the probe inlet to be at least 25 meters from the nearest road edge to avoid direct traffic emission impacts.

Question 4

What is a 'design value' in the context of NAAQS compliance?

Accepted Answer

The statistically derived ambient concentration used to compare against a NAAQS

Answer

A design value is the ambient air quality statistic — derived from monitoring data per EPA-specified averaging and calculation procedures — compared against the NAAQS to determine attainment status.

Question 5

Continuous Emission Monitoring Systems (CEMS) for SO2 at large point sources must meet performance specifications under:

Accepted Answer

40 CFR Part 75

Answer

40 CFR Part 75 establishes the continuous emission monitoring requirements and performance specifications for SO2, NOx, and CO2 at electric generating units and other large sources.

(CES) Certified Environmental Scientist Practice Test

(CES) Certified Environmental Scientist Practice Test

CES Air Quality Monitoring & Standards 3