CME Environmental Engineering & Sustainability 2 — Questions and Answers
Question 1: A municipal engineer is designing a stormwater retention pond. Which pollutant removal mechanism is LEAST effective in a wet retention pond?
- Sedimentation of suspended solids
- Biological uptake of nutrients
- Volatilization of heavy metals (Correct answer)
- Algal assimilation of phosphorus
Correct answer: Volatilization of heavy metals
Heavy metals are not significantly removed by volatilization; they are primarily removed through sedimentation and adsorption to settling particles.
Question 2: Under the Clean Water Act Section 402, which permit program regulates point source discharges of pollutants into navigable waters?
- RCRA
- NPDES (Correct answer)
- CERCLA
- TSCA
Correct answer: NPDES
The National Pollutant Discharge Elimination System (NPDES) under CWA Section 402 regulates point source discharges into waters of the United States.
Question 3: A city is evaluating its solid waste program. The waste hierarchy preferred order from most to least preferred is:
- Recycle, Reduce, Reuse, Recover, Dispose
- Reduce, Reuse, Recycle, Recover, Dispose (Correct answer)
- Reuse, Reduce, Recover, Recycle, Dispose
- Recover, Recycle, Reduce, Reuse, Dispose
Correct answer: Reduce, Reuse, Recycle, Recover, Dispose
The EPA waste management hierarchy prioritizes source reduction first, then reuse, recycling, energy recovery, and finally disposal as the last resort.
Question 4: Which greenhouse gas has the highest 100-year Global Warming Potential (GWP) relative to CO₂?
- Methane (CH₄)
- Nitrous oxide (N₂O)
- Sulfur hexafluoride (SF₆) (Correct answer)
- Hydrofluorocarbons (HFCs)
Correct answer: Sulfur hexafluoride (SF₆)
Sulfur hexafluoride has a 100-year GWP of approximately 23,500, the highest of any gas regulated under the Kyoto Protocol.
Question 5: A municipal engineer is assessing a brownfield site. Under CERCLA, which party is generally NOT liable for cleanup costs?
- The current owner who purchased the site knowing of contamination
- A bona fide prospective purchaser who conducted all appropriate inquiry (Correct answer)
- A transporter who selected the disposal site
- The original generator of the hazardous waste
Correct answer: A bona fide prospective purchaser who conducted all appropriate inquiry
CERCLA provides liability protection for bona fide prospective purchasers who conduct all appropriate inquiry and comply with continuing obligations.
Question 6: In a life cycle assessment (LCA), the 'cradle-to-gate' system boundary includes:
- Raw material extraction through end-of-life disposal
- Raw material extraction through product manufacture only (Correct answer)
- Product manufacture through consumer use only
- Consumer use through end-of-life disposal only
Correct answer: Raw material extraction through product manufacture only
Cradle-to-gate encompasses raw material extraction through the factory gate, excluding distribution, use, and end-of-life phases.
Question 7: A wastewater treatment plant is experiencing elevated effluent total nitrogen levels. Which treatment process specifically removes nitrogen through biological nitrification-denitrification?
- Trickling filter followed by clarification
- Activated sludge with anoxic zones (Correct answer)
- Chemical precipitation with alum
- Dissolved air flotation
Correct answer: Activated sludge with anoxic zones
Activated sludge systems with anoxic zones allow nitrification in aerobic zones and denitrification in anoxic zones to biologically remove nitrogen.
CME Environmental Engineering & Sustainability 2
A municipal engineer is designing a stormwater retention pond.
Which pollutant removal mechanism is LEAST effective in a wet retention pond?