CGM Remediation & Mitigation Strategies 2 — Questions and Answers
Question 1: Which bioremediation technique involves introducing oxygen and nutrients into contaminated groundwater to stimulate indigenous microbial degradation?
- Air sparging with nutrient injection (Correct answer)
- Pump-and-treat extraction
- Permeable reactive barrier installation
- Soil vapor extraction
Correct answer: Air sparging with nutrient injection
Air sparging with nutrient injection enhances in-situ bioremediation by providing oxygen and nutrients that stimulate native microorganisms to degrade contaminants.
Question 2: A grounds manager discovers lead contamination in a children's play area. What is the MOST immediate remediation priority?
- Begin soil excavation immediately
- Install a clean soil cap and restrict access (Correct answer)
- Apply lime to reduce pH
- Plant phytoremediation species
Correct answer: Install a clean soil cap and restrict access
Installing a clean soil cap and restricting access immediately eliminates exposure risk while a long-term remediation plan is developed.
Question 3: What does the term 'pump-and-treat' refer to in groundwater remediation?
- Pumping nutrients into soil to treat contamination
- Extracting contaminated groundwater, treating it above ground, and reinjecting or discharging it (Correct answer)
- Using pumps to aerate contaminated ponds
- Applying chemical treatments via irrigation pumps
Correct answer: Extracting contaminated groundwater, treating it above ground, and reinjecting or discharging it
Pump-and-treat systems extract contaminated groundwater to the surface for treatment before safe discharge or reinjection.
Question 4: Which cover crop is most effective at mitigating soil erosion on a steep slope during winter months in the mid-Atlantic US?
- Hairy vetch
- Winter rye (Correct answer)
- Crimson clover
- Buckwheat
Correct answer: Winter rye
Winter rye establishes quickly in cool temperatures and provides dense ground cover through the winter, effectively protecting slopes from erosion.
Question 5: A turf area shows compaction-induced water runoff. Which mitigation strategy provides the longest-lasting benefit?
- Topdressing with sand
- Deep-tine aeration followed by organic matter incorporation (Correct answer)
- Applying a wetting agent
- Increasing mowing height
Correct answer: Deep-tine aeration followed by organic matter incorporation
Deep-tine aeration combined with organic matter incorporation improves soil structure and macroporosity for long-term compaction relief.
Question 6: What is 'monitored natural attenuation' (MNA) as a remediation strategy?
- Allowing natural processes to reduce contaminants while monitoring their progress over time (Correct answer)
- Using natural plant species to absorb contaminants
- Installing natural stone barriers to contain contamination
- Applying organic mulch to naturally suppress contamination
Correct answer: Allowing natural processes to reduce contaminants while monitoring their progress over time
MNA relies on natural physical, chemical, and biological processes to reduce contaminant concentrations while ongoing monitoring verifies effectiveness.
Question 7: Which stormwater mitigation practice is most effective at removing total suspended solids (TSS) from parking lot runoff?
- Green roof installation
- Vegetated swale with check dams (Correct answer)
- Tree canopy expansion
- Impervious surface sealing
Correct answer: Vegetated swale with check dams
Vegetated swales with check dams slow runoff velocity and allow sediment to settle, effectively removing TSS from parking lot drainage.
CGM Remediation & Mitigation Strategies 2
Which bioremediation technique involves introducing oxygen and nutrients into contaminated groundwater to stimulate indigenous microbial degradation?