CPWM Landfill Gas Management and Energy Recovery

Question 1

What are the two primary components of landfill gas (LFG)?

Accepted Answer

Methane and carbon dioxide

Answer

LFG is composed primarily of approximately 50% methane and 50% carbon dioxide by volume, produced through anaerobic decomposition of organic waste.

Question 2

Under the Clean Air Act, which regulatory standard specifically governs MSW landfill air emissions requiring gas collection and control systems?

Accepted Answer

New Source Performance Standards (NSPS) under 40 CFR Part 60

Answer

MSW landfill air emissions are regulated under NSPS in 40 CFR Part 60, which sets emission thresholds that trigger gas collection and control system installation requirements.

Question 3

At what volume concentration of methane in ambient air does the lower explosive limit (LEL) become a safety concern?

Accepted Answer

5% methane by volume

Answer

The lower explosive limit (LEL) for methane is approximately 5% by volume in air, below which the gas-air mixture is too lean to ignite.

Question 4

What biological process is primarily responsible for landfill gas production in a sanitary landfill?

Accepted Answer

Anaerobic biodegradation of organic waste

Answer

LFG is generated when anaerobic microorganisms decompose organic waste in the oxygen-depleted environment deep within the landfill, producing methane and carbon dioxide.

Question 5

Which type of landfill gas combustion device most effectively controls trace organic compound emissions?

Accepted Answer

Enclosed ground flare

Answer

Enclosed ground flares achieve destruction efficiencies of 99%+ for trace organics by providing controlled residence time, high temperature, and turbulent mixing in a sealed combustion chamber.

(CPWM) Certified Professional in Waste Management Practice Test

(CPWM) Certified Professional in Waste Management Practice Test

CPWM Landfill Gas Management and Energy Recovery