STCW Marine Environmental Protection & Compliance 3 — Questions and Answers
Question 1: Under the Ballast Water Management Convention, what does the D-2 standard specify?
- Maximum volume of ballast water that can be exchanged at sea
- Maximum number of viable organisms permitted per cubic meter in discharged ballast water (Correct answer)
- Minimum distance from shore before ballast exchange
- Required treatment chemical concentrations
Correct answer: Maximum number of viable organisms permitted per cubic meter in discharged ballast water
The D-2 standard sets performance criteria limiting viable organisms (e.g., ≤10 organisms/m³ >50 µm) in discharged ballast water after treatment.
Question 2: Which annex of MARPOL specifically addresses sewage discharge from ships?
- Annex I
- Annex II
- Annex IV (Correct answer)
- Annex V
Correct answer: Annex IV
MARPOL Annex IV regulates the discharge of sewage from ships, setting distance and treatment requirements.
Question 3: What is the primary function of an oily water separator (OWS) aboard a ship?
- Remove salt from seawater to produce freshwater
- Separate oil from bilge water so effluent meets the 15 ppm discharge limit (Correct answer)
- Filter fuel oil before combustion
- Treat sewage before overboard discharge
Correct answer: Separate oil from bilge water so effluent meets the 15 ppm discharge limit
The OWS processes oily bilge water to reduce oil content to 15 ppm or less before any overboard discharge outside special areas.
Question 4: A tanker is cleaning cargo tanks using the crude oil washing (COW) method. This technique primarily helps by:
- Reducing the need for ballast water on the return voyage
- Minimizing oily residues left in tanks, thereby reducing slops requiring disposal (Correct answer)
- Increasing cargo capacity by removing scale
- Eliminating the need for an inert gas system
Correct answer: Minimizing oily residues left in tanks, thereby reducing slops requiring disposal
Crude oil washing uses crude oil itself to wash tank residues, significantly reducing the volume of oily slops that must be managed or discharged.
Question 5: Under MARPOL Annex VI, what is a 'Tier III' NOx limit and when does it apply?
- The least strict NOx standard, applicable globally
- The strictest NOx emission limit, applicable in NOx Emission Control Areas (NECAs) (Correct answer)
- The NOx limit for auxiliary engines only
- A voluntary standard for new-build LNG carriers
Correct answer: The strictest NOx emission limit, applicable in NOx Emission Control Areas (NECAs)
Tier III is the most stringent NOx standard under MARPOL Annex VI and applies to marine diesel engines operating in designated NOx Emission Control Areas.
Question 6: What must a ship do when it cannot discharge garbage at sea in compliance with MARPOL Annex V?
- Incinerate all garbage immediately regardless of type
- Retain the garbage on board and discharge it at a port reception facility (Correct answer)
- Discharge beyond 12 nautical miles if no other option exists
- Compact and jettison solid waste only
Correct answer: Retain the garbage on board and discharge it at a port reception facility
When at-sea discharge is not permitted under Annex V, vessels must retain garbage on board and offload it at a port reception facility.
Question 7: The Energy Efficiency Existing Ship Index (EEXI) under MARPOL Annex VI applies to:
- All ships regardless of age, as a design parameter only
- Existing ships above certain size thresholds to measure carbon intensity compared to a baseline (Correct answer)
- Only ships built after 2030
- Passenger ships exclusively
Correct answer: Existing ships above certain size thresholds to measure carbon intensity compared to a baseline
EEXI sets a required energy efficiency level for existing ships above certain gross tonnage thresholds, entering into force in 2023.
STCW Marine Environmental Protection & Compliance 3
Under the Ballast Water Management Convention, what does the D-2 standard specify?