CH Environmental Impact Assessment 3 — Questions and Answers
Question 1: Which federal permit is typically required before conducting hydrographic surveys that involve discharge of any pollutant into US waters?
- Section 404 permit
- NPDES permit (Correct answer)
- Section 10 permit
- Section 401 certification
Correct answer: NPDES permit
The National Pollutant Discharge Elimination System (NPDES) permit under the Clean Water Act governs discharges of pollutants into US waters.
Question 2: Cumulative impact analysis in an EIA examines:
- Only the direct effects of the proposed action
- The combined effects of the proposed action with other past, present, and reasonably foreseeable actions (Correct answer)
- Cost-benefit ratios of mitigation measures
- Agency review timelines
Correct answer: The combined effects of the proposed action with other past, present, and reasonably foreseeable actions
Cumulative impacts assess how the proposed action combines with other activities to affect the environment over time and space.
Question 3: A hydrographer discovers unexploded ordnance (UXO) on the seafloor during an EIA baseline survey. The first priority action should be to:
- Continue the survey and note location in the final report
- Immediately notify authorities and halt survey operations in the area (Correct answer)
- Remove the ordnance with available vessel equipment
- Photograph the item and proceed with survey
Correct answer: Immediately notify authorities and halt survey operations in the area
UXO discovery requires immediate notification of relevant authorities and cessation of operations in the area for safety and legal compliance.
Question 4: Which baseline data type is most relevant for assessing hydrographic survey impacts on submerged aquatic vegetation (SAV)?
- Water column salinity profiles
- Light attenuation and water clarity measurements (Correct answer)
- Surface wave height records
- Vessel traffic density
Correct answer: Light attenuation and water clarity measurements
SAV growth depends on light availability; turbidity and light attenuation data establish baseline conditions and predict survey-related impacts.
Question 5: The Marine Mammal Protection Act (MMPA) defines 'harassment' in the context of acoustic surveys as causing:
- Any audible noise in the water column
- A significant disruption of normal behavioral patterns (Correct answer)
- Reduction in fish prey availability
- Changes in water temperature
Correct answer: A significant disruption of normal behavioral patterns
Level B harassment under the MMPA includes acts that have the potential to disturb a marine mammal by disrupting its normal behavioral patterns.
Question 6: When assessing turbidity impacts from survey vessel operations in estuaries, which tidal condition typically produces the highest sediment resuspension risk?
- High water slack
- Maximum ebb or flood tidal current (Correct answer)
- Neap tide low water
- Spring tide high water
Correct answer: Maximum ebb or flood tidal current
Maximum tidal current velocities during peak ebb or flood create the greatest bottom shear stress, increasing sediment resuspension.
Question 7: Which EIA document tier follows an EA when significant impacts ARE identified?
- Record of Decision
- Finding of No Significant Impact (FONSI)
- Environmental Impact Statement (EIS) (Correct answer)
- Categorical Exclusion
Correct answer: Environmental Impact Statement (EIS)
If an EA reveals potentially significant impacts, a full Environmental Impact Statement must be prepared instead of issuing a FONSI.
CH Environmental Impact Assessment 3
Which federal permit is typically required before conducting hydrographic surveys that involve discharge of any pollutant into US waters?