CPWM Landfill Design and Operations 3

Question 1

What is the purpose of a groundwater monitoring network at a permitted landfill?

Accepted Answer

To detect potential liner leaks and groundwater contamination early

Answer

A groundwater monitoring network with upgradient and downgradient wells detects liner performance failures and potential contamination before it spreads significantly.

Question 2

In landfill gas management, what percentage of landfill gas (by volume) is typically methane at a mature municipal solid waste site?

Accepted Answer

50–60%

Answer

Mature municipal solid waste landfills typically generate gas that is approximately 50–60% methane and 40–50% carbon dioxide by volume.

Question 3

What minimum separation distance from the historical high groundwater table is required for the base of an MSW landfill liner system under federal Subtitle D regulations?

Accepted Answer

1 foot

Answer

RCRA Subtitle D requires the base of the liner system to be at least 2 feet (not 1 foot) above the historical high groundwater table—but the correct answer here is 2 feet.

Question 4

Which document establishes federal minimum criteria for municipal solid waste landfills in the United States?

Accepted Answer

RCRA Subtitle D (40 CFR Part 258)

Answer

40 CFR Part 258, promulgated under RCRA Subtitle D, establishes the federal minimum criteria for MSW landfill location, design, operation, groundwater monitoring, and closure.

Question 5

A final cover system for a closed MSW landfill must include a layer with hydraulic conductivity no greater than:

Accepted Answer

1×10⁻⁷ cm/s

Answer

Federal regulations require the low-permeability layer of a final cover to have hydraulic conductivity ≤1×10⁻⁷ cm/s, matching or exceeding the bottom liner performance.

(CPWM) Certified Professional in Waste Management Practice Test

(CPWM) Certified Professional in Waste Management Practice Test

CPWM Landfill Design and Operations 3