CME Environmental Engineering & Sustainability 3 — Questions and Answers
Question 1: A municipality plans to install a landfill gas-to-energy system. Landfill gas typically consists of approximately what percentage of methane?
- 10–20%
- 25–35%
- 45–60% (Correct answer)
- 70–85%
Correct answer: 45–60%
Landfill gas is typically composed of approximately 45–60% methane and 40–55% carbon dioxide, with trace amounts of other gases.
Question 2: Which U.S. regulatory program requires large municipal separate storm sewer systems (MS4s) to obtain permits controlling stormwater runoff?
- Clean Water Act Phase I and Phase II MS4 rules (Correct answer)
- Safe Drinking Water Act Surface Water Treatment Rule
- Resource Conservation and Recovery Act Subtitle D
- Clean Air Act New Source Performance Standards
Correct answer: Clean Water Act Phase I and Phase II MS4 rules
EPA's Phase I (1990) and Phase II (1999) MS4 rules under the CWA NPDES program require municipalities to reduce pollutants in stormwater discharges.
Question 3: In green infrastructure design, which practice is most effective at capturing and infiltrating stormwater at the source before it enters the storm drain system?
- Detention basin
- Bioretention cell (rain garden) (Correct answer)
- Underground storage tank
- Riprap channel lining
Correct answer: Bioretention cell (rain garden)
Bioretention cells infiltrate and filter stormwater at or near the point of rainfall, making them highly effective at source-level control.
Question 4: A municipal engineer calculates the carbon footprint of a water distribution system. Which operational component typically contributes the most greenhouse gas emissions?
- Pipe corrosion and material degradation
- Energy use for pumping (Correct answer)
- Chlorine disinfection byproduct formation
- Meter reading vehicle trips
Correct answer: Energy use for pumping
Energy consumption for pumping water through distribution systems is the dominant source of GHG emissions in water utilities, often representing over 80% of total emissions.
Question 5: Which environmental assessment tool is required for federal projects under the National Environmental Policy Act (NEPA) that may significantly affect the environment?
- Phase I Environmental Site Assessment
- Environmental Impact Statement (EIS) (Correct answer)
- Hazard and Operability Study (HAZOP)
- Facility Response Plan (FRP)
Correct answer: Environmental Impact Statement (EIS)
NEPA requires federal agencies to prepare an Environmental Impact Statement for major federal actions that significantly affect the quality of the human environment.
Question 6: A city wants to reduce urban heat island effect. Which strategy provides the greatest long-term temperature reduction benefit?
- Installing reflective (cool) pavements on roads
- Increasing urban tree canopy and green space coverage (Correct answer)
- Painting building rooftops white
- Installing misting stations in public plazas
Correct answer: Increasing urban tree canopy and green space coverage
Urban tree canopy provides the greatest long-term benefit through shading, evapotranspiration cooling, and stormwater management, reducing ambient temperatures by 2–8°C.
Question 7: Under RCRA, a hazardous waste generator that produces between 100 and 1,000 kg of hazardous waste per month is classified as a:
- Very Small Quantity Generator (VSQG)
- Small Quantity Generator (SQG) (Correct answer)
- Large Quantity Generator (LQG)
- Conditionally Exempt Small Quantity Generator (CESQG)
Correct answer: Small Quantity Generator (SQG)
EPA classifies generators producing 100–1,000 kg/month of hazardous waste as Small Quantity Generators (SQGs), subject to intermediate regulatory requirements.
CME Environmental Engineering & Sustainability 3
A municipality plans to install a landfill gas-to-energy system.
Landfill gas typically consists of approximately what percentage of methane?